Natural Nicotine Heals Honey Bees

January 23, 2017

NEONICOTINOID INSECTICIDES (e.g. thiamethoxam, imidacloprid, clothianidin) developed at Bayer Japan as safer alternatives (e.g. to human spray applicators) to the natural nicotine once widely used by farmers and gardeners, is now suspected of contributing to honey bee health problems like learning disorders and colony collapse. In contrast, natural nicotine, found in honey produced by bees working tobacco fields, as well as in pollen, nectar, leaves and other plant parts, is a nutrient and medicine helping to heal weak honey bee colonies, said Susan Nicolson of South Africa’s University of Pretoria at “Entomology Without Borders,” a joint meeting of the International Congress of Entomology (ICE) and the Entomological Society of America (ESA) in Orlando, FL.

Natural nicotine, even if produced organically in a sustainable recycling sort of way from tobacco waste products, is mostly shunned in organic farming and gardening. “Over 120 million sites will be returned on a web search on tobacco, but most will not be associated with plant science,” wrote USDA-ARS researcher T.C. Tso in Tobacco Research and Its Relevance to Science, Medicine and Industry. “Many plant scientists in academic institutions cannot obtain grant support for projects using tobacco as a research tool. Some even have to avoid tobacco because of the applying of ‘political correctness’ to academic research. The tobacco plant has served as a valuable tool since the dawn of plant and biological sciences, so it is indeed a great loss to scientific progress that a research tool already invested with so many resources and about which there is such abundant knowledge and such great potential for new advancement is now being wasted.”

Honey bees readily consume bitter alkaloids such as nicotine mixed in sugary plant nectars. Adult honey bees excel at detoxifying alkaloids such as nicotine, which should not be surprising, as survival depends on it. Younger, larval honey bees have fewer enzymes to detoxify nicotine, but also survive quite well even when their royal jelly contains high levels of nicotine. Honey bees and insects immune to nicotine, such as green peach (peach-potato) aphids, transform nicotine into less toxic butanoic acid. A knotty question naturally arises: If natural nicotine heals honey bees, why are synthetic neonicotinoids so terribly different? Are natural compounds like nicotine inherently more beneficial and their synthetic analogs (e.g. neonicotinoids) inherently bad, perhaps due to subtle differences in molecular structure? If bees and other pollinators are a major concern, perhaps natural product restrictions on nicotine need to be relaxed to provide competition to the synthetic neonicotinoids.

“Alkaloids, especially in the nicotine family, have been the main focus of tobacco research because alkaloids are the characteristic product of tobacco,” writes Tso. Dozens of other tobacco molecules are relatively overlooked, including sugar compounds providing least-toxic botanical insect and mite control. Anabasine (neonicotine), an alkaloid found in tobacco and other plants, has also been widely used as a natural insecticide. Strangely enough, anabasine is also an insect attractant and a poison gland product of Aphaenogaster ants. In a strange urban twist to the wild bird practice of lining nests with medicinal herbs emitting essential oils counteracting parasites: Researchers in Mexico discovered urban birds lining nests with cigarette butts to similar advantage. In times past, organic gardeners soaked cigarette butts in water to get a nicotine spray brew. Historically, most commercial nicotine insecticide used on farms and gardens was a sustainable tobacco waste extract.

There are 60-80 described tobacco or Nicotiana species, some available in seed catalogs and grown as ornamentals. Most Nicotiana species grow wild in the Americas, with some in Australia and Africa. “Tobacco plants are easy to grow and have a short growing period,” writes Tso. “Each tobacco plant may produce 14 g or about 150,000 seeds which may provide seedlings for 2 to 5 acres (1–3 ha) of field tobacco, depending on the type.” In Europe, oil extracted from tobacco seeds is being explored for an alternative bio-diesel fuel industry, with dry leftovers as animal feed.

Native American Nicotiana species are being integrated into China’s ancient agricultural interplanting tradition. When tobacco is interplanted in vineyard rows, tobacco roots and grape roots intermingle. Perhaps some sort of biological soil fumigation occurs. Whatever the mechanism, vineyards are cleansed of soil-dwelling phylloxera aphids, a pest that almost destroyed wine grape growing in France in the 1800s and is still a worldwide problem. According to the journal Chinese Tobacco Science, intercropping tobacco with sweet potato also alleviates soil and other pest problems, maximizing profits per unit area of land. Burley tobacco is intercropped with cabbage and other vegetable crops, according to the Journal of Yangtze University (Natural Science Edition).

Neonicotinoids are soluble in water and absorbed systemically by plants, and some are sprayed on urban lawns and landscapes. However, over 80% of synthetic neonicotinoids are applied to seeds prior to planting hundreds of millions of acres of corn, soybean, sunflowers and other crops. In Canada’s Ontario and Quebec provinces, 100% of corn seed is treated with neonicotinoids, said Nadejda Tsvetkov of Toronto’s York University at “Entomology Without Borders.” Though neonicotinoids were seldom found in corn pollen samples, somehow, perhaps by water transport, neonicotinoids are finding their way into clover and willow tree pollen far from corn fields.

“For a lot of farmers it is hard to get seeds untreated, especially corn,” as commercial seed is routinely treated with neonicotinoids regardless of need, said the University of Maryland’s Aditi Dubey at “Entomology Without Borders. In Maryland and other mid-Atlantic USA states where low pest pressures are the norm, neonicotinoid seed treatments are both unneeded and counterproductive. In 3-year Maryland rotations with double-cropped soybeans, winter wheat and corn, sowing seeds treated with thiamethoxam or imidacloprid reduced beneficial predatory ground beetles and increased slug damage to crops. Mid-Atlantic USA farmers typically apply 4 unnecessary prophylactic seed treatments every 3 years. Besides reduced biocontrol and more pest damage, soil accumulation over time is a disturbing agro-ecosystem possibility.

Alternative seed treatments include natural plant hormones such as salicylic acid and methyl jasmonate, which induce a natural immunity called induced systemic acquired resistance (SAR). Crops such as lettuce and argula (rocket) grown from seed treated with salicylic acid and methyl jasmonate also release volatile gases repelling pests such as sweet potato whitefly, a major worldwide pest, said Ben-Gurion University’s Mengqi Zhang at “Entomology Without Borders,” a gathering of 6,682 delegates from 102 countries. Numerous botanical materials and microbes have also been investigated around the world as alternative seed treatments.

A proactive approach to honey bee and bumble bee health includes a diversified landscape sown with herbs and medicinal botanicals for self-medication, not just natural nicotine from tobacco nectar or other sources. Thymol, an essential oil found in thyme and many other plants, is already sprayed in hives by beekeepers to combat Varroa mites. At “Entomology Without Borders,” North Carolina State University’s Rebecca Irwin reported laboratory choice tests where bumble bees rejected nicotine. In field tests, bumble bees were given a choice of different colored flowers each with a different botanical such as thymol, nicotine, anabasine and caffeine. Bumble bees only selected flowers with thymol to self-medicate. Interestingly, thymol and other herbal essential oils also synergize nicotine, boosting effectiveness against disease pathogens and perhaps also minimizing the likelihood of colony collapse.

Landscapes and hedgerows sown with medicinal plants such as thyme, sunflower and foxglove minimize bumble bee disease transmission, said Lynn Adler of the University of Massachusetts, Amherst. The current USA farm bill will actually pay farmers to plant bee-friendly sunflower edges or hedgerows around canola fields. Antimicrobial and medicinal honeys derived from sunflower, bay laurel (Laurus nobilis), black locust, etc., also effectively combat bee diseases like chalkbrood and foulbrood, said Silvio Erler of Martin-Luther-Universität in Halle, Germany at “Entomology Without Borders.”

Bee pharmacology is also useful in human medicine. In Oaxaca, Mexico gangrene is stopped and wounds are healed by combining maggot therapy and honey, reported Alicia Munoz. Maggot therapy uses sterilized (germ-free) green bottle fly maggots to disinfect and cleanse wounds by eating unhealthy tissues and secreting antibiotics, allowing healthy pink tissue to grow back under honey-soaked gauze. This cost-effective approach reduces hospital stays, lowers morbidity and can eliminate the need for surgery. It may sound yucky, but for diabetics and patients with bed sores or wounds where surgery is medically impossible, a few maggots and a little honey is preferable to amputating wounded or infected limbs.

Cancer-fighting bee propolis products were touched upon at “Entomology Without Borders” by Chanpen Chanchao of Chulalongkorn University in Bangkok, Thailand, where hives of stingless bees are reared like conventional honey bees. Cardol, a major component of propolis from the Indonesian stingless bee, Trigona incisa, causes early cancer cell death by disrupting mitochondrial membranes and “producing intracellular reactive oxygen species (ROS).” ROS are essential to energy, immunity, detoxification, chemical signaling, fighting chronic and degenerative diseases, etc. Cardol “had a strong antiproliferative activity against SW620 colorectal adenocarcinoma,” killing colon cancer cells within 2 hours, followed by complete cell necrosis within 24 hours. Thus, cardol is an “alternative antiproliferative agent against colon cancer.”


Food Sweetener Safely Slays Insects

August 27, 2015

CERTAIN SUGARS CONSIDERED SAFE as sweeteners in the human food supply can double as environmentally-friendly pest remedies, and even make biological control of insects by beneficial fungi more practical for households, farms and gardens. Considering that caffeine from coffee grounds can be used against deadly dengue mosquitoes and that a variety of traditional herbs can blast away bed bugs, insecticidal sugar compounds should come as no surprise. Perhaps the only remedy more surprising is that rain water or simulated rain sprays from hoses or irrigation equipment can safely wash away pests with no toxic pesticide residues to worry about in the environment.

Using sugars directly to slay insects is somewhat unusual. However, sugars are commonly used as attractants, for instance to lure fruit flies, moths or ants to baits and traps both for population control and as a survey method or monitoring tool. California citrus growers have a long history of using sugar sprays as an IPM (integrated pest management) strategy to lure fruit-scarring citrus thrips to organic or botanical formulations of ryania (“from woody stem and root materials of plants of the genus Ryania”) or sabadilla (alkaloids from seeds of a lily bulb, Schoenocaulon officinale). “INTEGRATED PEST MANAGEMENT implies that techniques used to manage one pest species should not disrupt techniques used to manage other pests of the same crop,” wrote J.D. Hare and Joseph Morse in the Journal of Economic Entomology. “In citrus pest management in California, this situation is well illustrated in the choice of pesticides for the management of one major pest, citrus thrips, Scirtothrips citri (Moulton), without disruption of several effective biological control agents of the other major pest, California red scale, Aonidiella aurantii (Maskell).”

That sugars can be lethal to pests and be a source of environmentally-friendly pesticides is not exactly intuitive. “Potential of the non-nutritive sweet alcohol erythritol as a human-safe insecticide” was the strangely intriguing title of Drexel University’s Sean O’Donnell’s presentation at the Entomological Society of America (ESA) annual meeting. Many of the details were previously published in PLoS ONE, an open access journal, and in part because of the origins of the research in a grade school science project by one of the researcher’s sons, aspects of the story have been widely reported in various media. “Erythritol is a zero-calorie sweetener found in fruits and fermented foods,” summarized Lauren Wolf in Chemical & Engineering News, and “is Generally Recognized As Safe by the Food & Drug Administration and has been approved as a food additive around the globe.”

“Many pesticides in current use are synthetic molecules such as organochlorine and organophosphate compounds,” and “suffer drawbacks including high production costs, concern over environmental sustainability, harmful effects on human health, targeting non-intended insect species, and the evolution of resistance among insect populations,” write the researchers in PLoS ONE. “Erythritol, a non-nutritive sugar alcohol, was toxic to the fruit fly Drosophila melanogaster. Ingested erythritol decreased fruit fly longevity in a dose-dependent manner, and erythritol was ingested by flies that had free access to control (sucrose) foods in choice and CAFE (capillary feeding assays) studies…

“We initially compared the effects of adding five different non-nutritive sugar substitutes (Truvia, Equal, Splenda, Sweet’N Low, and PureVia,” wrote the researchers in PLoS ONE. “Adult flies raised on food containing Truvia showed a significant reduction in longevity…We noted that adult flies raised on food containing Truvia displayed aberrant motor control prior to death. We therefore assayed motor reflex behavior through climbing assays…Taken together with our longevity studies, these data suggested some component of the non-nutritive sweetener Truvia was toxic to adult Drosophila melanogster, affecting both motor function and longevity of this insect…

“Our initial analysis of sweeteners included two sweeteners that contained extracts from the stevia plant, Truvia and Purevia. While adult flies raised on food containing Truvia showed a significant decrease in longevity compared to controls, this was not the case for flies raised on Purevia. These data suggest stevia plant extract was not the toxic element in these sweeteners. Purevia contains dextrose as a bulk component, while Truvia contains erythritol as a bulk component…To determine if erythritol was the toxic component of Truvia, we repeated our longevity studies on food containing equal weight/volume (0.0952 g/ml) of nutritive sugar control sucrose, and non-nutritive sweeteners Truvia, Purevia, and erythritol. We assured the flies were successfully eating the foods containing these sweeteners through dye labelling the food with a non-absorbed blue dye (blue food), and visual confirmation of blue food present in fly abdomens and proboscises daily…The average percentage of blue abdomens throughout the study were 97.46%.”

“These data confirm all treatment foods (including Truvia and erythritol treatments) were consumed by adult flies, and suggest mortality was not due to food avoidance and starvation…A large body of literature has shown that erythritol consumption by humans is very well tolerated, and, indeed, large amounts of both erythritol and Truvia are being consumed by humans every day throughout the world. Taken together, our data set the stage for investigating this compound as a novel, effective, and human safe approach for insect pest control. We suggest targeted bait presentations to fruit crop and urban insect pests are particularly promising.”

Interestingly, a few decades ago UK researchers found that the sweeteners (sugar alcohols; polyols) erythritol, glycerol and trehalose rendered more effective several insect biocontrol fungi, Beauveria bassiana, Metarhizium anisopliae and Paecilomyces farinosus. These insect-killing fungi need a relative humidity (RH) near 100% for germination of their conidia (seed-like propagules). “Conidia with higher intracellular concentrations of glycerol and erythritol germinated both more quickly and at lower water activity,” wrote UK researchers J.E. Hallsworth and N. Magan in the journal Microbiology. “This study shows for the first time that manipulating polyol content can extend the range of water availability over which fungal propagules can germinate. Physiological manipulation of conidia may improve biological control of insect pests in the field…Although fungal pathogens have been used to control insect pests for more than 100 years, pest control has been inadequate because high water availability is required for fungal germination.”

Curiously, erythritol and glycerol, besides being sweetening substances, also function as antifreeze compounds. Certain Antarctic midges, known as extremeophiles for living in an ultra-cold habitat, ingest and sequester erythritol from their food plants; and as antifreeze it protects the adult flies from freezing. Indeed, many mysteries remain. Besides being found in green plants like stevia and in lower amounts in fruits, erythritol is found in certain mushrooms, lichens and algae. Human and animal blood and tissues apparently have low endogenous levels of erythritol; and erythritol is a yeast fermentation product (hence in sake, beer, wine). In human medicine, erythritol has been used for coronary vasodilation and treating hypertension; and according to Japanese microbiologists, erythritol ingestion may mean fewer dental cavities (caries) than sucrose sugar.


Silicon Bed Bug Weaponry

May 4, 2015

BED BUGS CAN be spiked and trapped by tiny spears like leaf hairs, and can become dehydrated or dessicated and rendered harmless by certain forms of silicon, the second most abundant element in planet Earth’s crust (28%) after oxygen (47%). That silicon can be the bane of bed bugs is indeed odd when one considers that silicon permeates our world from beach sands, opals, agates and quartz crystals to sandpaper, semiconductors, glasses, ceramics, optical fibers and cosmetic products. Indeed, the famous French scientist and silkworm entomologist, Louis Pasteur, whose name has become synonymous with the germ theory of medicine, predicted silicon’s eventual service in human medicine; though Pasteur was probably not thinking along the lines of silica gels and desiccant diatomaceous earth dusts as remedies for the 21st century’s worldwide medical plague of bed bugs.

Despite its commonness in nature and the human environment and potential uses in human medicine, the use of silicon products comes with caveats to users, who might want to wear sufficient protective clothing and respirators to avoid inhaling the products. Strangely enough, that much maligned metabolic waste product, carbon dioxide, which along with sunlight is essential to photosynthesis and life on planet Earth, is perhaps a safer component (e.g. as a lure or attractant) when integrated into bed bug traps. Food grade diatomaceous earth made from freshwater diatoms is considered relatively nontoxic; whereas filtering grade diatomaceous earth (e.g. the type used for swimming pool filters) is a crystalline form with inhalation toxicity.

“Louis Pasteur (1822-95) said that silicon would prove to be a treatment for many diseases and in the first quarter of the twentieth century there were numerous reports by French and German doctors of sodium silicate being used successfully to treat conditions such as high blood pressure and dermatitis,” wrote British chemist John Emsley in his superb compendium, Nature’s Building Blocks (An A-Z Guide to the Elements). “By 1930, such treatments were seen to have been in vain and the medication fell out of favor. So things rested, until the discovery that silicon might have a role to play in human metabolism, and then followed suggestions that it could have a role in conditions such as arthritis and Alzheimer’s disease, but no new treatment based on these suggestions has yet emerged. Meanwhile, silicon continues to be linked with a disease of its own: silicosis. Miners, stone-cutters, sand-blasters and metal-grinders develop this lung condition which is a recognized occupational disorder caused by the inhalation of minute particles of silica…” Symptoms include coughing, wheezing and shortness of breath; a more aggressive form of silicosis associated with certain types of asbestos can develop into lung cancer and has been a rich source of litigation for occupational exposure in the USA.

While silica products should be used sparingly (a caution that should also apply to most sprays) or not at all by some people (e.g. existing respiratory problems; perhaps seek a medical opinion before using), they might prove for many others the tipping point for winning the bed bug war as part of an integrated approach that controls bed bugs (many of which are pesticide resistant) using a multiple arsenal of weapons including herbal oils, clutter reduction, heat, sealing crack and crevice harborages, traps, pheromones, carbon dioxide, vacuuming under baseboards, etc.

At the 2014 Entomological Society of America (ESA) annual meeting, Kyeong-Yeoll Lee of South Korea’s Kyungpook National University (Daegu) reported that silica in the form of diatomaceous earth (Perma-Guard(TM) or Fossil-Shell(R)) acted as a synergist when heat (hot air) fumigations substituted for chemical fumigants such as methyl bromide. Though the test insect was Indian meal moth, a worldwide pest of stored grain and many other packaged agricultural products, it would not be surprising to find that heat treatments combined with silica products like diatomaceous earth will also prove efficacious and perhaps also synergistic against bed bugs. Indeed, heat treatments may induce bed bugs to move around more, which could hasten contacting diatomaceous earth and water loss.

At the same 2014 ESA meeting, Virginia Tech (Blacksburg, VA) researcher Molly Stedfast provided some impressive results via the time-consuming process of first educating apartment residents about bed bugs and then painstakingly vacuuming along baseboards to suck up as many bed bugs as possible before applying the silica products under the baseboards to further reduce bed bug populations. This integrated (IPM; integrated pest management) approach required quite a bit of manual labor, as furniture had to be moved to gain access to the baseboards before vacuuming and then applying silica gel or dust products.

Stedfast tested two silica products, Mother Earth(TM) D, a highly-absorptive desiccant dust made from 100% freshwater diatomaceous earth, and CimeXa(TM) Insecticide Dust, a 100% amorphous silica gel. The silica dust or gel injures the insect cuticle (outer protective “skin”), letting water leak out and leading to dehydration (providing relative humidity is not extremely high, above 81%; and free water is unavailable). Both the diatomaceous earth and silica gel products were “very effective at killing bed bugs even at 10% of the label rate.” Going above the label rate was a waste of resources, as only so much product can contaminate the bed bugs. Bed bugs can die within 24 hours of contacting the silica products, but air currents that blow the dusts around can be a problem; also the products need to stay moist and not dry out to be effective. Among Stedfast’s biggest headaches is the application equipment, which was not very robust.

The patent literature reveals that inventors such as Roderick William Phillips in Vancouver are working on improved spray apparatuses for applying diatomaceous earth: “There is disclosed a spray apparatus for holding contents comprising diatomaceous earth and a compressed propellant for propelling the diatomaceous earth. There is also disclosed use of diatomaceous earth to control a population of bedbugs…diatomaceous earth, a naturally occurring siliceous sedimentary rock that includes fossilized remains of diatoms. However, known methods of applying diatomaceous earth can be cumbersome. For example, known methods of applying diatomaceous earth may undesirably require handling the diatomaceous earth, for example to transfer the diatomaceous earth from a container not having an applicator to a separate applicator apparatus. Also, known applicator apparatuses may apply diatomaceous earth unevenly, which may be wasteful or ineffective. In general, known methods of applying diatomaceous earth may be sufficiently complex so as to require professional involvement, which may undesirably add to cost and delay of bedbug treatment. Also, numerous types of diatomaceous earth are available, and different types of diatomaceous earth vary widely and significantly from each other. It has been estimated that there are approximately 100,000 extant diatom species…and may vary widely and significantly in size and shape across a very large number of diatom species…”

At the University of British Columbia (Vancouver), Yasmin Akhtar and Murray Isman demonstrated that both diatomaceous earth and herbal or botanical compounds such as neem, ryania and rotenone are to varying degrees transported by adult bed bugs and contaminate other adults and younger bed bug nymphs. “Our data clearly demonstrate horizontal transfer of diatomaceous earth and botanical insecticides in the common bed bug,” said Akhtar and Isman. “Use of a fluorescent dust provided visual confirmation that contaminated bed bugs transfer dust to untreated bed bugs in harborage. This result is important because bedbugs live in hard-to-reach places and interaction between conspecifics can be exploited for delivery and dissemination of management products directed at this public health pest…This result is important because bedbugs live in hard-to-reach places (cracks, crevices, picture frames, books, furniture) and as such interaction between the members of the colony can be exploited for delivery and dissemination of control products.”

At the 2014 ESA annual meeting, Akhtar suggested protecting travelers and suppressing bed bug transit by building diatomaceous earth into luggage, mattresses and fabrics. Diatomaceous earth provided 96% repellence; bed bug mortality was zero at 24 hours, but 93% after 120 hours. Diatomaceous earth could also be applied to box springs, dressers and headboards, and under carpets and inside drywall. A diatomaceous earth aerosol provided 81% bed bug mortality at 30 days, and was still active and being transferred from dead bed bugs to live bed bugs.

Diatom species mined for diatomaceous earth are stunning in their architectural variety and beauty. Ultimately, the silicon secrets of living diatoms has the potential to transform “the manufacture of siloxane-based semiconductors, glasses, ceramics, plastics, elastomers, resins, mesoporous molecular sieves and catalysts, optical fibers and coatings, insulators, moisture shields, photoluminescent polymers, and cosmetics,” wrote UCSB marine scientist Daniel E. Morse. “The manufacture of these materials typically requires high temperatures, high pressures or the use of caustic chemicals. By contrast, the biological production of amorphous silica, the simplest siloxane [(SiO2)n], is accomplished under mild physiological conditions, producing a remarkable diversity of exquisitely structured shells, spines, fibers and granules in many protists, diatoms, sponges, molluscs and higher plants. These biologically produced silicas exhibit a genetically controlled precision of nanoscale architecture that, in many cases, exceeds the capabilities of present-day human engineering. Furthermore, the biological productivity of siloxanes occurs on an enormous scale globally, yielding gigatons per year of silica deposits on the floor of the ocean. Diatomaceous earth (composed of the nanoporous skeletons of diatoms) is mined in great quantities from vast primordial deposits of this biogenic silica.”


Herbal Oils Blast Bed Bugs

March 28, 2015

HERBAL OILS such as NEEM can reduce bed bug populations when integrated with other pest control technologies such as traps. As desperation hits with more bed bug populations resistant to more conventional synthetic pesticides, more herb and essential oil formulations and fumigations, as well as silicon dioxide-based gels and dusts such as diatomaceous earth, are being integrated with other bed bug remedies such as clutter reduction and heat fumigation.

Those in thrall to chemical industry protocols adhere to the standard that a remedy must kill 95% in laboratory tests. But it is most often a hypocritical standard, as over time bed bugs are almost guaranteed to become genetically selected for resistance to widely used synthetic pesticides. According to Virginia Tech researchers: “A frightening resurgence of bed bug infestations has occurred over the last 10 years in the U.S. and current chemical methods have been inadequate for controlling this pest due to widespread insecticide resistance…While DDT was initially effective for bed bug control, resistance to the cyclodienes was well documented among different bed bug populations by 1958…bed bugs had developed resistance to organophosphate insecticides, including malathion by the 1960s…While there have been many hypotheses regarding the cause of the bed bug resurgence, the cause is at least partially explained by bed bug resistance to insecticides, in this case, those in the pyrethroid class,” including deltamethrin resistance in New York City bed bugs.

To that conclusion, I would add “over-reliance on synthetic chemical pesticides” to the exclusion of designing habitations to be inhospitable to bed bugs and alternative control methods. Oddly enough, herbal remedies not killing 95% are often subject to persecutory calls of marketplace banishment by the EPA, FDA, FTC or one of the myriad other USA.gov regulatory bureaucracies. An Alternative in the Internet age is letting people decide for themselves via Internet search engines before buying. To some extent, government regulation of herbal pest control efficacy is unnecessary when scientific test results can be posted on the Internet and debated.

An integrative approach can make excellent use of herbal remedies providing perhaps 40% or 60% bed bug reduction; in conjunction with heat treatments, sharp silicon dioxide crystals and other remedies that collectively might add another 30%, 40% or 50% bed bug reduction. It’s all mathematics, which many people hate; but nonetheless a 60% bed bug reduction from an herbal remedy combined with a 40% reduction from clutter reduction, heat fumigation or traps can easily equal over 95% control (the laboratory standard adhered to by those one-trick chemical ponies sometimes called “nozzle heads”).

In other words, herbal oils and other alternative treatments can leverage themselves when intelligently combined with other pest control methods such as heat, clutter reduction and traps. That should be intuitive, but it runs counter to the entomology training of the average PhD in the USA. The late “Professor (Robert) van den Bosch of the University of California was one of the developers of Integrated Pest Management” (IPM) and an advocate of biological controls; and he made the case for a multi-faceted approach to cotton and food crop pests long ago in books like The Pesticide Conspiracy (University of California Press).

Bed bugs and the urban environment of hotels, apartments, cracks, crevices, mattresses, trains, buses, backpacks and luggage of course present a different set of problems than a homogeneous field of crops or a laboratory spray arena. But you be the judge of whether herbal fumigations work against bed bugs: At the Entomological Society of America annual meeting, Korean researcher Jun-Ran Kim (Rural Develop Admin, Suwon-si Gyeonggi-do, South Korea) compared 120 herbal or botanical essential oils to the best conventional pesticides for controlling insecticide-susceptible and insecticide-resistant adult bed bugs hiding in protected places (as bed bugs do; e.g. cracks, crevices, inside electrical sockets).

Kim singled out two essential oils, those from peppermint (Mentha piperita) and myrtle (Myrtus communis) plants, as most effective and worth further development as bed bug fumigants. So, should the headline read: “Essential Oils a Failure as Bed Bug Fumigants,” as 118 of 120 essential oils did not make the cut. Indeed, fewer than 2% of the botanical oils tested, peppermint and myrtle, were singled out as potential bed bug fumigants. Or should the headline read: “Essential Oils Effective Bed Bug Fumigants,” or “Peppermint and Myrtle Oils Prove Essential Oils Can Work as Bed Bug Fumigants.”

Rue, an ancient herb, needs to be tested against bed bugs. Natural products researchers report: “An infusion of Ruta chalepensis leaves rubbed onto skin has been purported to be repellent to mosquitoes and other insects by farmers and shepherds in rural and mountainous areas of Marche and Latium, Central Italy. In the same Italian countryside, Ruta graveolens leaves were set under the bed to repel bugs and mice (Guarrera 1999). A decoction of Ruta species also has been used topically against scabies, lice, and fleas, to repel insects and to treat intestinal worms in livestock.”

Intriguingly, rather than following up on rue under the bed to fight bed bugs, Italian researchers veered off in another direction: Rue, as a sustainable weed control alternative for corn field weeds such as purslane and pigweed: “Poisonous plants are neglected sources of natural herbicides. An infusion of such a plant rue (Ruta graveolens L.) was tested…rue infusion (100 g/l) and its isolated allelochemicals…open up a promising avenue in the search of natural herbicides.”

Other researchers envision the disease-fighting properties of herbs such as rue and powders such as sodium bicarbonate (baking soda or bicarbonate of soda) being harnessed as alternatives to synthetic fungicides. Indeed, in organic and sustainable conventional farming, rue “at low rates…may lessen the onset of fungicide resistance” against powdery mildew, brown spot and other plant diseases in diverse crops, including strawberries.

Italian researcher Giovanni Aliottal and colleagues in a paper titled “Historical Examples of Allelopathy and Ethnobotany from the Mediterranean Region,” write: “Ruta graveolens L. (Rutaceae), or common rue, originating in Southern Europe, is an evergreen shrub with bluish-green leaves that emits a powerful odour and has a bitter taste. The plant is cited in the ancient herbals and has deep roots in folklore, alchemy and even demonology. Rue has been regarded from the earliest time as successful in warding off contagion and preventing the attacks of fleas and other noxious insects. The name rue derives from the Greek “reuo” (= to set free), because the plant is efficacious in various diseases. Rue was the chief ingredient of the famous antidote to poison used by Mithridates. It was also known to produce erythema and pustular eruptions on human skin. Many remedies containing rue as well as its abortive properties were mentioned by Pliny the Elder in his Naturalis Historia (XX, 143). In Europe, rue was considered a powerful defense against witches during the Middle Ages. Piperno, a Neapolitan physician, in 1625, recommended rue as a treatment for epilepsy and vertigo. Today, the aerial parts of the plant are eaten in Italian salads, and are said to preserve the eyesight. Rue is currently mentioned in the pharmacopoeias of 28 countries where it is considered mainly as a stimulating, antispasmodic, diuretic and emmenagogue. Moreover, fresh and dried leaves are used to preserve and to flavour beverages and foods such as liquor (grappa) and wine, cheese and meat.”

Ruta graveolens is the scientific name for garden rue or herb-of-grace, one of about 1,500 species in the plant family Rutaceae (includes oranges, lemons, other citrus). A native of the Balkans and southeastern Europe grown worldwide, rue is known as sudab or sadab in India, arvada in Tamil, aruda in Singhalese, gedung minggu in Javanese and geruda in Malay. Ruta chalepensis is the scientific name for fringed rue, Aleppo rue or Egyptian rue. Rue researchers D. H. Tejavathil and B. L. Manjula in India summarize: “Ruta graveolens L., a member of Rutaceae, is well known for its wide utilities such as ornamental, aromatic and culinary in addition to medicinal properties. Medicinal value of this taxon is attributed to the accumulation of flavonoids, furanocoumarins, acridine alkaloids, furanoquinolins and also essential oils which led to its recognition as one of the sought after traditional medicinal plants by pharmaceuticals.” Perhaps a bit dangerous, too; according to Egyptian researchers: “On moist skin in direct sunlight, it leads to photosensitivity. The essential oil is a central nervous system depressant and at high doses has become a narcotic.”

A major rue essential oil component, 2-undecanone, is nicely summarized in wikipedia: “2-Undecanone is used in the perfumery and flavoring industries, but because of its strong odor it is primarily used as an insect repellent or animal repellent. Typically, 1–2% concentrations of 2-undecanone are found in dog and cat repellents…” According to its web site claiming “invention” by Dr. R. Michael Roe and referencing 3 patents: “North Carolina State University is currently seeking an industry partner to commercialize a novel, natural insect repellent for mosquitoes, ticks, chiggers, bedbugs, house dust mites, cockroaches, and other pests…A researcher at North Carolina State University has discovered that undecanone and related structures are repellents of mosquitoes, ticks, bed bugs, cockroaches, thrips, aphids, deer flies, gnats and other animals. In some tests, these compounds were found to be more effective than DEET…”

The Flowers of Chania web site provides a nice overview of rue species used as medicine in Crete, grown in Netherlands botanical gardens, and mentioned in Shakespeare’s Hamlet. Unlike the Balkan bean leaf remedy for spearing bed bugs, which has recently sparked the interest of those desperate for bed bug remedies, medicinal plants in the rue family known since ancient times have escaped scientific scrutiny against bed bugs. Probably much to the delight of bed bugs worldwide. According to researchers in India, “The most frequent intentional use of the plant has been for induction of abortion.” If only that powerful rue activity could be integrated to naturally abort bed bug populations just enough to allow humans a more bite-free sleep.

On the Internet are a varied array of commercial products with herbal essential oil and soap (detergent) ingredients sold for potential use against bed bugs (and usually other pests, as well). The herbal ingredients do not need extensive safety testing, as they are GRAS (Generally Recognized as Safe) substances commonly found in foods, cosmetics, etc.

According to the USA FDA (Food and Drug Administration) web site: ““GRAS” is an acronym for the phrase Generally Recognized As Safe. Under sections 201(s) and 409 of the Federal Food, Drug, and Cosmetic Act (the Act), any substance that is intentionally added to food is a food additive, that is subject to premarket review and approval by FDA, unless the substance is generally recognized, among qualified experts, as having been adequately shown to be safe under the conditions of its intended use, or unless the use of the substance is otherwise excluded from the definition of a food additive. Under sections 201(s) and 409 of the Act, and FDA’s implementing regulations in 21 CFR 170.3 and 21 CFR 170.30, the use of a food substance may be GRAS either through scientific procedures or, for a substance used in food before 1958, through experience based on common use in food.”

In other words, if there is a long tradition of eating the stuff and smearing it on your body, it is likely not to need hundreds of millions of dollars and decades of testing and regulatory agency compliance like a pharmaceutical product. So, you don’t have to wait 15 years for a bed bug remedy that will be several times more costly (to recoup the regulatory expenses) than what is already available. Being publicly sold on the Internet, samples of these GRAS pesticide products can often be obtained free of charge by researchers for scientific studies. Sometimes the studies, even if taxpayer or public funded, are published in respected commercial journals and hidden from public perusal behind formidable paywalls. But Internet search engines can usually at least turn up abstracts, media reports and summaries of varying quality and usefulness.

Rutgers researchers compared 11 herbal and detergent products (e.g. Sodium Lauryl Sulfate) and two synthetic pesticide products against bed bugs. A nice summary by the researchers published in an industry trade publication and titled “Natural Pesticides for Bed Bug Control: DO THEY WORK?” was made freely accessible via the Internet. Bed bugs were placed in laboratory chambers offering no escape from spray contact; a valid approach for most product comparisons. But given that many bed bug populations are pesticide resistant and that in real rooms bed bugs hide and avoid spray contact, real world results are usually lower than the lab numbers. These are more or less truisms, for both botanical and synthetic pesticide products. Which is why pest control operators often are called back to spray multiple times over several months or years; and why you need an integrative approach (relying on more than just sprays) and plenty of patience to rid yourself of bed bug infestations. A quick overview of integrative bed bug alternatives with a resource list is found in the Jan. 2015 issue of the IPM Practitioner (as of this writing, still available for free Internet download).

According to the Rutgers researchers, Temprid SC [Imidacloprid (21%) and Beta-Cyfluthrin (10.5%)] killed 100% of exposed adult bed bugs coming in contact with the spray in three days, and “was significantly more effective than Demand CS” [Lambda-Cyhalothrin (9.8%)]. The best herbal formulations were a bit slower: “EcoRaider and Bed Bug Patrol were the most effective biopesticides in both tests. EcoRaider [Geraniol (1%), Cedar Extract (1%) and Sodium Lauryl Sulfate (2%)] caused 100 percent mortality after 10 days in both tests. Bed Bug Patrol [Clove Oil (0.003%), Peppermint Oil (1%) and Sodium Lauryl Sulfate (1.3%] caused an average of 92 percent and 91 percent mortality after 10 days in the first and second experiment, respectively. Neither of these two products caused more than 75 percent mortality at three days after treatment…Bed Bug Bully [Mint Oil (0.25%), Clove Oil (0.3%), Citronella Oil (0.4%) and Rosemary Oil (0.4%)] caused 60 percent mortality after 10 days.”

Thus, the need for a patience and a multi-faceted, integrative approach to bed bug control using herbal or synthetic pesticides, tiny leaf hair-like spikes, CO2, traps, heat, cold, steam, mattress encasements, vacuuming, pheromones, clutter reduction, diatomaceous earth, silica gels, etc. If winning the war against bed bugs were easy, the insects would have been extinct long ago and you would not be reading this.


Organic Dairies Suck Flies (CowVac)

December 5, 2014

Rest assured, a CowVac is not a veterinary vaccine of some sort that magically provides insect control or renders cows autistic. Rather, it is about producing organic milk and organic milk products like butter and yogurt. A CowVac is a suction or vacuum device incorporated into a larger trapping apparatus that removes blood-sucking flies that can be an even worse livestock plague than mosquitoes or ticks. Besides being bad economics (too expensive), pesticides repeatedly applied at ever higher doses quickly select for pesticide-resistant biting flies; i.e the flies become immune. Which is not to say that insects will not develop some ingenious solution, like holding on tighter, to avoid being sucked up by strong suction. But at least development of stronger suction devices and better ways to knock insects off animals would not add pesticide residues to the environment, food chain and human diets. A human equivalent, awaiting invention, would be an enclosure of some sort designed to knockoff and suck up (vacuum off) bed bugs before they bite (see previous blog, on bed bug desperation time innovative research).

“Seven years in the making: The Cow-Vac removes horn flies from dairy cattle” was the title of a special display at a members symposium “Honoring the Career and Contributions of Veterinary Entomologist Donald A. Rutz” at the Entomological Society of America (ESA) annual meeting in the beer brewing capital of the world, Portland, Oregon. On its web site, the Center for Environmental Farming Systems (CEFS) at North Carolina State University (NCSU) in Raleigh reports: “This innovative solution is now part of routine cattle management at the CEFS Dairy Unit and has allowed the herd to be insecticide-free for 5 years.” In other words, this “alternative fly management system” designed by Steve Denning and D. Wes Watson demonstrated “the feasibility of producing organic milk.”

“The trap removed between 1.3 and 2.5 million flies annually from the research station cattle,” Denning and Watson reported to the ESA in Portland. “Prior to the installation of the trap in 2007, the cattle routinely had horn fly populations above 1000 flies per animal and would require insecticide applications for horn fly control. With a vacuum trap in place, dairy cattle at CEFS have not required or have been treated with an insecticide.” With each of the thousand horn flies sucking blood 10-12 times per day, the blood loss and associated problems were huge (USA estimated losses are over $2.26 billion per year), and organic animal agriculture was considered questionable.

“The first walk-through pasture fly trap consisted of a covered structure designed to brush flies from the animals as they passed through, with the fleeing flies captured in the screened hollow walls,” reported Denning and Watson at the ESA meeting in Portland. “Modifications to the Bruce trap have been introduced over the years. These modified traps employ the same basic mode of action; curtains to dislodge flies and light, either natural or fluorescent, to attract flies to a cage, or bug zapper. In addition to curtains, the CowVac uses air pressure to dislodge flies, and vacuum to capture flies, trapping them in a chamber until death.” So far, the Animal Rights movement has yet to recognize a right to food (animal blood, in this case) for biting flies (also animals); and the flies die a natural death from lack of animal blood as a food source. Cruelty to animals (flies), perhaps; and fodder for an ethics debate. But if you want organic milk, butter, meat, yogurt, etc…

There are YouTube videos on the vacuum trap, and the Northeast Organic Dairy Producers Alliance has an in-depth article on the CowVac and its development by fly biocontrol specialist Tom Spalding of Spalding Labs: “…the Horn Fly is very tough to control. It’s resistant to most every chemical control. It only reproduces in cow pastures, which means there is always productive breeding material available as no one cleans up pasture pats…For the past 16 years, North Carolina State University entomologists, Dr. Wes Watson and Steve Denning, have been researching IPM practices for pest fly control for commercial livestock and poultry operations…They have seen it all, testing at least 100’s of products…repellent on most and only a few animals with pesticide, to using electric traps, light traps, walk thru traps, feed thru products, ear tags, oilers, you name it…in 2006 as Steve was watching flies get scrapped off cows going thru a walk in trap, and then following the cow out the exit and getting right back on, he had an AH HA moment of “let’s see if we could vacuum up those little buggers”…Organic Valley heard about this unit and they sponsored a test, placing 6 units on North Carolina dairies in 2012…we made a trip to Raleigh, NC to see it. I knew from our efforts using Fly Predators to control Horn Flies that this little insect was a big deal. It took a lot of work as you had to put the Fly Predators in the pastures where the cows has just been and that only worked for those doing intensive grazing. Harrowing or running a screen drag over the pastures made a big difference too, but all those things took more time than most dairymen had. If this vac thing worked it would solve a horrible problem every grazier has…We agreed to license the technology from NC State and so began the redesign for production and optimization. This is the second unlikely alignment of the stars. I run a beneficial insect company, but I’m a mechanical engineer (ME) by schooling and in the 30 years prior had started a number of high tech companies…we refined the airflow on real animals. While the simulated cow got us very close to optimized performance, we actually were blowing too much air…”


Herbicide-Resistant Grains Reduce Global CO2

June 25, 2014

THE WAR BANNERS of the North American Global Climate Change Brigade are flying high and flapping in the wind as the West’s Crusade Against CO2 (carbon dioxide) ratchets up against the alleged Lex Luther of fossil fuels, the super-villain coal favored by the up-and-coming industrial economies of India and China. But the USA has an ace in the hole, an agricultural crop super-hero warrior equivalent of the comic book-heroes Batman & Robin or the US Navy Seals ready to colonize world grain farming areas and help save the day by reducing global CO2 emissions. Though its longer term sustainability is open to question and the development of herbicide resistant weeds are almost an assured part of the package, an interesting case can be made for using grain crops resistant to herbicides (mainly glyphosate at the moment) in no-till and minimum-tillage farming systems to reduce global CO2 emissions.

“Weeds are the most significant of the economic and environmental pests, and they are the target of much of the pesticides applied throughout the world,” wrote Rachel E. Cruttwell McFadyen in an Annual Review of Entomology article titled Biological Control of Weeds. “Herbicides comprise 47% of the world agrochemical sales, and insecticides 29%. Weeding, usually by hand, accounts for up to 60% of total pre-harvest labor input in the developing world.” All this herbicide use is having predictable ecological results. According to to the International Survey of Herbicide Resistant Weeds: “There are currently 432 unique cases (species x site of action) of herbicide resistant weeds globally, with 235 species (138 dicots and 97 monocots). Weeds have evolved resistance to 22 of the 25 known herbicide sites of action and to 155 different herbicides. Herbicide resistant weeds have been reported in 82 crops in 65 countries.”

However, when the herbicide use is coupled with grain crops that are herbicide-resistant in no-tillage or minimum-tillage farming systems, the reduction in CO2 emissions from the farming systems is quite dramatic. In a 2008 article titled “Glyphosate: a once-in-a-century herbicide” in the journal Pest Management Science, S.O. Duke and S.B. Powell wrote: “Glyphosate-Resistant crop use worldwide in 2005 resulted in a reduction of carbon dioxide emissions and potential additional soil carbon sequestration equivalent to the removal of about 4 million family cars from the road in terms of effects on global carbon balance.” This positive view of Roundup Ready® crops, which are genetically modified organisms (GMOs) resistant to the herbicide glyphosate, was echoed in 2012 in the Weed Science Society of America’s journal, Weed Science: “Adoption of conservation tillage in the United States since 1982 is credited with reducing average soil erosion by 30%, raising the amount of soil carbon, and lowering CO2 emissions.”

In 2010, the combined biotech crop-related carbon dioxide emission savings from reduced fuel use and additional soil carbon sequestration were equal to the removal from the roads of 8.6 million cars, equivalent to 27.7% of all registered cars in the UK (United Kingdom),” wrote Graham Brookes and Peter Barfoot in their 2012 UK report. “Based on savings arising from the rapid adoption of no till/reduced tillage farming systems in North and South America, an extra 4,805 million kg of soil carbon is estimated to have been sequestered in 2010 (equivalent to 17,634 million tonnes of carbon dioxide that has not been released into the global atmosphere).”

If you subscribe to the CO2-centric consensus that temperature change on planet Earth revolves almost exclusively around the evil-demon molecule, CO2, then like night follows day the case for no-tillage farming schemes using herbicide-resistant GMOs (genetically modified organisms) that sequester carbon, reduce soil erosion, minimize fossil fuel use and reduce CO2 emissions in a major way is tough to fight, even if the GMO scheme has some discomforting side-effects to swallow.

On the other hand, the consensus or majority view can sometimes turn out to be dead wrong, be it CO2 or commodity prices (e.g. houses, gold). I remember vividly the early 2000s, being in the 17% minority when an overwhelming 83% of the USA population were “in consensus” with the world “intelligence community” consensus belief in the absolute certainty of another evil demon threatening life on planet Earth, Iraqi Weapons of Mass Destruction. Turned out to be Iraqi Weapons of Mass Deception. But realistically, we cannot demand God-like perfection and 100% correctness from the consensus-making machinery. On a more scientific level, before the USA came into existence as a nation-state, there was a very sincere consensus belief (perhaps 97%) that the Earth was flat and ships sailing from Europe towards North America would be swallowed by dragons or perish in the void. A skeptical Christopher Columbus undeniably demonstrated otherwise. Likewise, Aristotle’s most accepted ancient scientific wisdom was later revised; and a skeptical Albert Einstein punched holes into previous beliefs about the nature of the physical world.

Organic and traditional grain growers do have some good reasons to resist growing herbicide-resistant GMO (genetically modified organisms) grains, despite the reduced CO2 emissions. Indeed, it is theoretically possible to develop organic herbicides (e.g. allelopathic extracts of sorghum, eucalyptus, sesame, sunflower, tobacco and brassica fight weedy wild oats & canary grass in wheat fields) and implement organic no-till and minimum-till systems with cover crops, green manures, mulches, intercropping, crop rotations, etc.

But for the moment, herbicide-resistant GMO grains have been voluntary adopted (no mandates or penalties for non-use) and dominate in the Americas for reasons having little to do with direct concern for CO2 emissions. Reduced CO2 emissions from farming systems incorporating herbicide-resistant GMO crops might be called a pleasant side effect; though logically it could become a global selling point, if not a global mandate (perhaps even enforced by the USA, EU, NATO or United Nations) as part of the “War on CO2.”

In point of fact, the IPCC (International Panel on Climate Change), which sets the European Union (EU) and global agenda on these matters is on record in their official reports, that herbicide-resistant GMOs used in no-tillage and minimum-tillage farming are a valid remedy for reducing CO2 emissions.

Though Brookes and Barfoot caution against taking their numbers too literally, because they are estimates based on assumptions and models (e.g. IPCC data), the contribution to CO2 emissions reduction from herbicide-resistant GMO crops and no-tillage farming is hard to dispute. If the consensus case against CO2 as the climate-change evil demon molecule is fully accepted and considered closed and beyond debate, then the case for herbicide-resistant GMO grains becomes politically correct and GMO-skeptics should logically be housed with CO2-skeptics in the same denial and heretic camp. However, the evil-demon status of CO2 is open to alternative interpretations incorporating some beneficial attributes of carbon atoms and CO2 molecules as essential to life on planet Earth.

Call it carbon skepticism or CO2 denial if you wish, but the famous Italian chemist Primo Levi, a concentration camp survivor (who later committed suicide) and knew firsthand that majority opinion can sometimes be tragically wrong, questioned the mainstream CO2 obsession and wrote: “Carbon dioxide, that is, the aerial form of carbon…this gas which constitutes the raw material of life, the permanent store upon which all that grows draws, and the ultimate destiny of all flesh, is not one of the principal components of air but rather a ridiculous remnant, an ‘impurity,’ thirty times less abundant than argon, which nobody even notices. The air contains 0.03 percent (CO2)…This, on the human scale, is ironic acrobatics, a juggler’s trick, an incomprehensible display of omnipotence-arrogance, since from this ever renewed impurity of the air we come, we animals and we plants…”

Lost in the shrill certitude and climate change bullying is the fact that CO2 is only 1 of about 200 atmospheric gases interacting with each other and other factors such as cloud cover in still not fully understood ways affecting climate and temperature; lack of adequate understanding for computer input is one reason why the computer model predictions are inherently prone to error and inaccuracy. Side effects of reduced atmospheric CO2 may include less plant photosynthesis (e.g. less food crop growth) and less water transpiration by plants (which may affect cloud cover and rainfall in ways that actually increase global warming).

Coal gets more of the blame for CO2 emissions. But, ironically, scrubbing (removing) sulfur dioxide (SO2) from burning coal caused much of the global warming blamed on CO2 by shrinking the Earth’s sulfate layer (which offsets the warming effect of CO2). Though the SO2 from coal burning is a pollutant we would not want back, it illustrates the complexity of the atmosphere, where selectively manipulating one thing leads to other unexpected problems. For example, put back the SO2 “scrubbed” from burning coal, and almost like magic the CO2 warming effects vanish (along with the rationale for global carbon taxes, cap-and-trade, and herbicide-resistant GMO crops to fight CO2). It’s like Dem Bones song on YouTube. Indeed, the cooling of the Earth when SO2 or sulfates are put back into the atmosphere by natural sources like volcanic eruptions is very dramatic. According to the U.S. Geological Survey:

“The most significant climate impacts from volcanic injections into the stratosphere come from the conversion of sulfur dioxide to sulfuric acid, which condenses rapidly in the stratosphere to form fine sulfate aerosols. The aerosols increase the reflection of radiation from the Sun back into space, cooling the Earth’s lower atmosphere or troposphere. Several eruptions during the past century have caused a decline in the average temperature at the Earth’s surface of up to half a degree (Fahrenheit scale) for periods of one to three years. The climactic eruption of Mount Pinatubo on June 15, 1991, was one of the largest eruptions of the twentieth century and injected a 20-million ton (metric scale) sulfur dioxide cloud into the stratosphere at an altitude of more than 20 miles. The Pinatubo cloud was the largest sulfur dioxide cloud ever observed in the stratosphere since the beginning of such observations by satellites in 1978. It caused what is believed to be the largest aerosol disturbance of the stratosphere in the twentieth century, though probably smaller than the disturbances from eruptions of Krakatau in 1883 and Tambora in 1815. Consequently, it was a standout in its climate impact and cooled the Earth’s surface for three years following the eruption, by as much as 1.3 degrees at the height of the impact. Sulfur dioxide from the large 1783-1784 Laki fissure eruption in Iceland caused regional cooling of Europe and North America by similar amounts for similar periods of time.”

Yes, major volcanoes are rarely more than a few per century; but there is also possibility of global cooling from a nuclear winter triggered by nuclear explosions. In 2011, a “rare” combination of a tsunami triggering a nuclear power plant meltdown intimidated the Japanese into shutting down their “clean” (as far as CO2 and greenhouse gas emissions go) nuclear power plants and substituting CO2-emitting fossil fuels; ironically, going against the United Nations Kyoto Protocol treaty negotiated in Kyoto, Japan. The Kyoto Treaty, whose stated “goal is to lower overall emissions from six greenhouse gases – carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, HFCs, and PFCs,” had a few other flaws: “Please recall that China and India are Exempt from Kyoto standards,” writes Mish’s Global Economic Trend Analysis. “The US opted out because China was not a party. Canada signed the treaty but in 2012 Canada Leaves Kyoto Protocol, Lets China Buy Into Oil Sands.”

CO2 concentrations in the atmosphere of planet Earth have actually dropped dramatically over geologic time, and are nowhere near returning to former levels that favored plant life over animal life. University of Cambridge chemist John Emsley notes that natural sources, mainly the metabolism of food sources by plant and animal life, are still responsible for most CO2 production on planet Earth. In his book, Nature’s Building Blocks, Emsley writes: “The Earth’s early atmosphere may have contained a lot of carbon dioxide and methane, but once life evolved that began to change. Today, there is very little of these gases and a lot of oxygen instead, thanks chiefly to the action of plants which convert carbon dioxide and water into carbohydrate and oxygen by photosynthesis. The Earth’s atmosphere contains an ever-increasing concentration of carbon dioxide and carbon monoxide, from fossil fuel burning, and of methane, from paddy fields and cows. Human contributions to these sources are still minor compared with natural sources: most carbon dioxide comes from plants, microbes and animals, while methane is given off by swamps, marshes and termite mounds.”


Whole Hog Into Debugging Michigan Apples

April 9, 2014

FROM TIME to TIME over the course of the centuries, agriculture seems to reinvent itself, and if anything modern agriculture based on the industrial model seems to be unconsciously integrating the higher animals back into the fruit tree groves, at least among those Michigan entomologists and farmers who appreciate the overlooked virtues of the hog as a faithful human servant at the beck and command of its handlers for hunting down pests that have become resistant to pesticides and difficult to control even with the latest pheromone mating disruption technologies. To those combating or hunting down feral pigs and wild boar disrupting native ecosystems and rooting up farm crops, turning pigs loose in apple, cherry, pear and other fruit tree orchards is likely to seem a heretical notion belonging to renegade rednecks or radical hippie farmers from the counterculture past stuck in a continuous time-warp loop with Spock and the characters from Star Trek.

One of the advantages of attending Entomological Society of America meetings is being able to follow themes like “livestock-crop reintegration,” which Ceres Trust Research Grants have been funding for Michigan State University entomologists like Krista Buehrer and Matthew Grieshop. Basically, organic hogs provide organic fruit orchards control of weeds and insect pests like plum curculio (Conotrachelus nenuphar), codling moth (Cydia pomonella) and Oriental fruit moth (Grapholita molesta). “The rotation of hogs through different pastures and orchards with supplemental nutrition sources” is also “a method of livestock-crop integration that avoids the problem of adhering to National Organic Policy (NOP) and Good Agricultural Practices (GAP) policies restricting the application of manure prior to harvest,” wrote Buehrer in “Graduate Student Final Report – Ceres Trust Research Grant.”

Rotating organic hogs through organic fruit orchards to clean out weeds and insect pests hidden inside fallen fruits, traces its roots to Charles Valentine Riley, who pioneered modern biological control in the orange orchards of Los Angeles, California. In his 1871 “Third Annual Report on the Noxious, Beneficial and other Insects of the State of Missouri,” Riley said that for apple curculio “the only real remedy is the destruction of infested fruit.” In 1890, writing in the Iowa Agricultural Experiment Station Bulletin, C.P. Gillette suggested grazing orchards with sheep or hogs to eat the insect-infested “windfallen fruit” on the orchard floor and thereby reduce pest populations.

From the 1800s into the Roaring Twenties, Iowa apple growers could not get rid of apple curculios by shaking the trees, cultivating the soil, pruning, or spraying arsenic pesticides, leading B.B. Fulton in 1925 and 1926 to test hog grazing on the “Apple Grove Orchards south of Mitchellville, Iowa.” Writing in the Journal of Agricultural Research in 1928, Fulton said: “The experiments with pasturing pigs were successful from a business standpoint. A cost account kept for the two years showed that this method of control was more than economical, for it actually netted a profit. In 1925 each pig returned a net profit of $10 above cost and feed and in 1926 a net profit of $7.65…five pigs per acre can, if properly handled, clean up the early dropped apples in an orchard and thus control the apple curculio. The critical time for such control, as shown by the seasonal history data, is from the middle of June until about the middle of July. Pigs weighing about 100 pounds are the best size for this purpose since they do not tramp down the low branches. They do not feed from the trees…”

Krista Buehrer told the 2012 ESA Annual meeting in Austin, Texas that weekly rotations (June-August) of grazing hogs eating dropped fruit (containing pests inside) on the orchard floor produced marketable organic hogs and reduced pests without harming earthworms or beneficial insects (e.g. lady beetles, lacewings, ground beetles, spiders, parasitoid wasps, tachinid flies, syrphid flies, dolichopodid flies, ants). ““There were 3 control plots and 3 hog grazed plots,” said Buehrer. “Grazed plots were bordered by electric fencing to prevent hogs from escaping. Twenty-four Berkshire hogs were rotated through each grazed plot twice. In 2012, they were in each plot for 1.5 weeks per rotation, for a total of 3 weeks per grazed plot. In 2013 they were in each plot for 1 week per rotation, for a total of 2 weeks per grazed plot. Hogs ranged from 50-90 lbs (23-41 kg) each.”

Hog grazing really only scratches the surface of changing fruit orchard floor management, which includes cover crops, living mulches, composts, etc. Perhaps it is more a case of everything old becoming new again, as grazing by cattle, sheep, goats, wild pigs and boar are considered part of traditional European agroforestry systems.


Bed Bug Herbal Remedies Work Well With Traps

July 15, 2013

THE NEEM TREE (Azadirachta indica), a medicinal mahogany tree (Meliaceae) native to arid broadleaf and scrub forests in Asia (e.g. India), has been used for over 4,000 years in Vedic medicine and has a heavy, durable wood useful for furniture and buildings because it is resistant to termites and fungi. Nonetheless, despite US EPA registration as a pesticide for crop and home use and a long legacy of neem seed oil use for cosmetics, shampoos, toothpastes and medicines in India, Ohio State University researcher Susan Jones could not find any households near her Columbus, Ohio, home willing to try neem in her bed bug control experiments.

“We had no study takers because of the regulatory requirements,” which scared off people, Jones told the Entomological Society of America (ESA) Annual Meeting. “You have to read page after page to residents about toxicity without being able to talk about the toxicity of alternative products” not as safe as neem. In October 2012, an empty house with bed bugs became available for research when its occupant opted to escape a bad bed bug infestation by leaving the infested home; and inadvertently transferred the infestation to their new home.

Jones monitored the empty house by placing in each room four (4) Verifi(TM) CO2 (carbon dioxide) traps and four (4) Climbup(R) Interceptor traps. Visual inspections revealed few bed bugs. On October 24, 2012, prior to neem treatments, 38 bed bugs were captured in Climbup(R) traps, indicating bed bug infestations only in the master bedroom and bed of the empty house. Eight Verifi(TM) traps captured 48 bed bugs in the dining room, guest room and master bedroom. As part of an IPM (integrated pest management) approach using multiple treatment tools: Electrical sockets were treated with MotherEarth(R) D diatomaceous earth; 3.67 gal (13.9 l) at a rate of 1 gal/250 ft2 (3.9 l/23 m2). Gorilla Tape(R) was used to seal around the doors and exclude bed bug movement from other rooms.

The neem seed oil product, Cirkil(TM) RTU, was sprayed in various places, including on books, backs of picture frames and cardboard boxes. Vials of the insecticide-susceptible Harlan bed bug strain were placed around the house for on-site neem seed oil vapor toxicity assays. Two days after spraying, bed bug mortality from neem seed oil vapors was highest in confined spaces; with 48% mortality in vials placed between the mattress and box spring, versus 28% mortality in open spaces. On Nov. 6, two weeks post-treatment, 123 dead bed bugs were vacuumed up and live bed bugs were detected in a second bedroom. Bed bug numbers were low because the monitoring traps were doing double duty, also providing population suppression by removing many bed bugs.

Herbal oils can also be combined with heat chambers at 50 C (122 F) or carbon dioxide (CO2) fumigation chambers to combat bed bugs. However, heat chambers are expensive, and CO2 fumigation with dry ice can pose handling difficulties and room air circulation issues, Dong-Hwan Choe of the University of California, Riverside, told the Entomological Society of America (ESA).

Herbal essential oils are useful against head lice, and in Choe’s native Korea clove oil from from the leaves and flower buds of clove plants (Syzygium aromaticum) is used in aromatherapy and as a medicine. Clove oil is rich in GRAS (Generally Recognized as Safe) compounds such as eugenol, beta-caryophyllene and methyl salicylate (sometimes called wintergreen oil), which are useful as vapors in control of insects and microbes. In dentistry, clove oil (eugenol) is widely used as an antiseptic and pain reliever.

Clove essential oils work faster in closed spaces or fumigation chambers (e.g. vials, Mason jars) than in open spaces. Essential oils are even slower to kill bed bugs when orally ingested. In experiments at varied temperatures, Choe placed 10 bed bugs in plastic vials with mesh tops. The vials were placed inside 900 ml (1.9 pint) Mason jars; filter paper treated with essential oils was placed on the underside of the Mason jar tops.

Herbal essential oils worked faster at higher temperatures. For example, methyl salicylate fumigant vapors provided 100% bed bug mortality in 30 hours at 26 C (79 F); 10 hours at 35 C (95 F); and 8 hours at 40 C (104 F). Eugenol vapors produced similar results; there were no synergistic or additive effects from combining eugenol and methyl salicylate. Choe told the ESA that his future trials will include: botanical oil granules; exposing bed bug-infested items to essential oil vapors; and checking for sublethal essential oil effects on parameters such as female bed bug reproduction.

Narinderpal Singh of Rutgers placed bed bugs on cotton fabric squares treated (half left untreated) with synthetic pesticide and herbal essential oil products: 1) Temprid(TM) SC, a mixture of imidacloprid and cyfluthrin (neonicotinoid and pyrethroid insecticides); 2) Ecoraider(TM) (Reneotech, North Bergen, NJ) contains FDA GRAS ingredients labeled as “made from extracts of multiple traditional herbs that have been used in Asia for hundreds of years for therapy and to repel insects;” 3) Demand(R) CS, which contains lambda-cyhalothrin (a pyrethroid insecticide); 4) Bed Bug Patrol(R) (Nature’s Innovation, Buford, FL), a mixture with the active ingredients listed as clove oil, peppermint oil and sodium lauryl sulfate.&&

Temprid(TM) SC and Demand(R) CS proved best on the cotton fabric test. In arena bioassays with Climbup(R)Interceptor traps, none of the four insecticides were repellent to bed bugs (i.e. repellency was less than 30%). Ecoraider(TM) was equal to Temprid(TM) SC and Demand(R) CS against the tough to kill bed bug eggs. Singh concluded that field tests of Ecoraider(TM) as a biopesticide were warranted.

Changlu Wang of Rutgers told the ESA that travelers might be protected from bed bug bites and bring home fewer bed bugs if protected by essential oil repellents, as well as by more traditional mosquito and tick repellents like DEET, permethrin and picaridin. Repellents are more convenient and less expensive than non-chemical alternatives such as sleeping under bed bug tents and bandaging yourself in a protective suit.

Isolongifolenone, an odorless sesquiterpene found in the South American Tauroniro tree (Humiria balsamifera), is among the botanicals being studied, as it can also be synthesized from turpentine oil and is as effective as DEET against mosquito and tick species. Bed bug arena tests involve putting a band of repellent around a table leg, with a Climbup(R)Interceptor trap below. If the bed bug falls into the trap, it is deemed to have been repelled from the surface above. In actual practice, the bed bug climbs up the surface and goes horizontal onto the treated surface and drops or falls off if the surface is repellent. Isolongifolenone starts losing its repellency after 3 hours; 5%-10% DEET works for about 9 hours. In arena tests with host cues, 25% DEET keeps surfaces repellent to bed bugs for 2 weeks. But isolongifolenone is considered safer, and Wang is testing higher rates in hopes of gettting a full day’s protection.


Pollinator-Friendly Lawns: Flowers or No Flowers?

April 28, 2013

TURF is a $25 BILLION USA INDUSTRY, said Nastaran Tofangsazi of the University of Florida (Apopka, FL), a sex pheromone researcher looking to complement biocontrols like beneficial Beauveria bassiana fungi and Steinernema carpocapsae nematodes to control the browning and uneven grass growth caused by tropical sod webworm (Herpetogramma phaeopteralis) in Florida’s $9 billion worth of turfgrass. Also at the Entomological Society of America (ESA) annual meeting, Auburn University’s R. Murphey Coy noted that the USA’s 164,000 km2 (63,320 square miles) of turf is the USA’s most irrigated crop. Turfgrass irrigation consumes 300% more water than corn; plus 4.5 pounds (2 kg) of nitrogen per 1,000 square feet (93 m2).

Alabama is among the top USA turfgrass-producing states, and Auburn University researchers are looking to reduce turfgrass water, nitrogen and iron inputs by colonizing grass seeds and roots with easy to apply sprays of plant growth promoting rhizobacteria (PGPR). Blends of PGPR species such as Bacillus firmis, Pseudomonas and Rhizobium in turfgrass and cotton induce systemic resistance to pestiferous Fusarium fungi and triple parasitic wasp biocontrol of the caterpillar larvae of moth pests like fall armyworm (Spodoptera frugiperda).

Not everyone is a fan of turfgrass lawns, and before the modern chemical era lawns were more like fragrant flowery meadows. “Agricultural experts and agribusiness are bound by the idea that even land that has lost its natural vitality can still produce crops with the addition of petroleum energy, agricultural chemicals, and water…considering this form of agriculture to be advanced,” wrote Japanese agriculturist and philosopher Masanobu Fukuoka in the book, Sowing Seeds in the Desert (edited by Larry Korn).

“When I suggested that it would be a good idea to plant fruit trees to line the streets in towns and cities and to grow vegetables instead of lawns and annual flowers, so that when the townspeople were taking a walk, they could pick and eat the fruit from the roadside, people were surprisingly enthusiastic,” said Fukuoka. “When I suggested that it would be good to scatter the seeds of clover and daikon on the existing lawns so that in two or three years the clover would overcome the lawn and the daikon would take root amid the ground cover, interestingly, it was the Asian people and Asian-Americans who said they would try it right away. Most Americans would just laugh and agree with the theory, but they were cautious about putting it into practice. The reason, I believe, is that it would challenge their adherence to ‘lawn’ culture. If they cannot overcome this prejudice, there will be a limit to the growth of family gardens in the United States.”

“It seems that the main goal in the life of the average American is to save money, live in the country in a big house surrounded by large trees, and enjoy a carefully manicured lawn,” wrote Fukuoka. “It would be a further source of pride to raise a few horses. Everywhere I went I preached the abolition of lawn culture, saying that it was an imitation green created for human beings at the expense of nature and was nothing more than a remnant of the arrogant aristocratic culture of Europe…Because residential lots are large in the United States, a family vegetable garden can provide for all the food needs of a typical family, if they are willing to do the work. In Japan, a residential lot about a quarter acre would be enough to allow near self-sufficiency and provide a healthy living environment, but I learned—to my envy—that in many suburban and rural areas of the United States, people are not allowed to build houses on small lots.”

On closer inspection, modern American lawns are more often a biodiverse mixture of turfgrass and flowering plants like clover and dandelions. Kentucky bluegrass lawns may be 30% white clover, which favors native pollinators like bumblebees. Clover and dandelion flowers attract honey bees, bumble bees, parasitic wasps that kill pests, hover flies (syrphids) that eat aphids, and carnivorous rove and ground beetles eating snails, slugs, caterpillars and other pests. Nonetheless, tons of herbicides go onto USA lawns to eradicate clover and dandelions as weeds, often as part of fertilizer and insecticide mixtures.

Turf biodiversity is all well and good, but only as long as the clover and dandelion flower nectar is pure and uncontaminated by pesticide cocktails. Lawns laden with clover and dandelion flowers provide bees and beneficial insects with “a big gulp of nectar,” the University of Kentucky’s Jonathan Larson told the ESA annual meeting in Knoxville, Tennessee. When those “big gulps of nectar” are laced with certain neonicotinoid pesticides, the effects can ripple through the ecological food chain.

When turfgrass pesticide labels say, ‘Don’t treat flower heads,’ “Follow the label to the letter of the law” to avoid poisoning pollinators, said Larson. Or get rid of the flowering plants in the lawn by mowing the turf before spraying. Or delay pesticide sprays until after clovers, dandelions and other lawn flowers have finished flowering. Clover control in lawns using herbicides is difficult, and usually not feasible, Larson told the ESA. Hence, mowing is the preferred strategy for removing flowering lawn weeds before spraying pesticides.

In enclosure experiments with tents confining bees in the turf, mowing the turf before pesticide treatment mitigated the problem, resulting in more bees and more honey. In 2012, bees were tented on clothianidin-treated turf for 6 days and then moved for 6 weeks to a Lexington, Kentucky, horse ranch with unsprayed turf. Clothianidin reduced the rate of bumble bee weight gain, but at the end of 6 weeks the bees were starting to catch-up. But overall, the 6-day pesticide exposure still resulted in reduced bumble bee weight gain, less foraging and reduced queen and hive reproduction several weeks later. Chlorantraniliprole, which has a different mode of action (muscular), did not produce these adverse effects. Larson also told the ESA that clothianidin, a widely used neonicotinoid turf pesticide, also reduces decomposers (detritivores) like soil-dwelling earthworms and springtails more than chlorantraniliprole.

Besides supporting more soil life, more biocontrol organisms, and healthier crops of pollinating bees, you get a healthier turfgrass lawn if you do not need pesticides and do not have to mow so often. “Mowing height is an easily manipulated cultural practice that can have an impact on ecological conditions,” Samantha Marksbury from the University of Kentucky, Lexington, told the ESA. “Taller grass usually supports a more diverse ecosystem and increases natural enemies. Increasing cutting height stimulated deeper roots, yielding a healthier turf with less need for insecticide. Higher mowing height decreases need for irrigation and the canopy prevents water loss.”

Taller turf (raised mowing height) also tends to be more robust and more tolerant of white grubs. Nevertheless, about 75% of turf is lush residential monocultures (mostly one grass species) that is heavily fertilized, dosed with chemical herbicides and frequently mowed, Emily Dobbs of the University of Kentucky, Lexington, told the ESA. However, the ecology of grass cutting or mowing gets quite complex and has seasonal variations. In May, turf with a low mowing height (2.5 inches; 6.4 cm) was hotter, drier, and had the most predatory ground beetles, rove beetles and spiders. Later in the season and Sept/Oct, turf with a higher mowing height (4 inches; 10.2 cm) was cooler, wetter, and had the most predators.

Historically, in the Middle Ages in England, going back many centuries (even before Chaucer) before the age of chemical farming and gardening, lawns were “flowery meads” with roses, violets, periwinkles, primroses, daisies, gillyflowers and other colorful, fragrant flowers interplanted right into the turf. The idea of planting a lawn with one species of grass made no sense, though a camomile lawn or plot came into being for infirmary gardens in England after 1265, as this medicinal aromatic plant helped other plants growing nearby in poor soils and grew faster the more it was trodden.

“There were no flower-beds of the sort familiar to us,” wrote Teresa McLean in her 1981 book, Medieval English Gardens. “The simplest type of flower garden was the flowery mead, wherein low-growing flowers were planted in turf lawns, sometimes walled, sometimes left open, to make a beautiful domestic meadow. The flowery mead was the locus amoenus of God’s beautiful world.”

“Trees were often planted in raised turf mounds, surrounded by wattle fences, which doubled as seats,” wrote McLean. “Medieval lawns, unlike modern ones, were luxuriously long, and full of flowers and herbs; they were fragrant carpets to be walked, danced, sat and lain upon. What modern lawn could find a poet to write about it as Chaucer wrote about the one in the Legend of Good Women?

Upon the small, soft, sweet grass,
That was with flowers sweet embroidered all,
Of such sweetness, and such odour overall…”


Medicinal Caterpillar Fungus High in Nepal’s Himalayan Mountains

December 27, 2012

CATERPILLAR FUNGI ARE not everybody’s finger food, though their beautifully-sculpted medicinal mushrooms are rich in fiber, amino acids, minerals and vitamins. The caterpillar fungus of commerce, Cordyceps sinensis, grows high in the Himalayan Mountains in the larvae (caterpillars) of equally high-altitude Asian ghost moths (genus Hepialus). An ancient medicine or tonic, caterpillar fungus is in reality part insect (mummified caterpillar) and part fungus; and perhaps a conundrum for vegetarians, who might have to take a pass on its medical benefits because of its animal kingdom (insect) component.

Cordyceps is an abundant resource of useful natural products with various biological activity, and it has been used extensively as a tonic and health supplement for subhealth patients, especially seniors, in China and other Asian countries,” write Kai Yue and colleagues at Sichuan Agricultural University in an article pre-published online in October 2012 in the Royal Pharmaceutical Society’s Journal of Pharmacy and Pharmacology.

For perhaps thousands of years (at least several hundred) in China and other Asian countries, “Cordyceps sinensis (Caterpillar fungus) has been used as a tonic for longevity, endurance, and vitality,” write Chinese Academy of Sciences researchers Zhenquan Liu et al. in an Open Access journal, Behavioral and Brain Functions. “Many studies have shown that Cordyceps sinensis modulates immune responses, inhibits tumor cell proliferation, enhances hepatic function, regulates insulin sensitivity” and modulates steroid production.

“Although Cordyceps sinensis is extensively used in Chinese medicine, it lacks scientific grounds for its efficacy,” write Liu et al. In other words, it has worked like magic for centuries; providing practical benefits, though the exact mechanisms of how it works are unknown or speculative. The Chinese researchers argue that even proponents of modern medicine objecting to traditional natural or folkloric medical treatments could benefit from studying the caterpillar fungus. Their argument is that the research results from studying the mechanisms of how the caterpillar fungus works to heal or prevent disease could also be used to develop more conventional medical or drug treatments.

Caterpillar fungus could be particularly useful for certain brain strokes, where modern medicine lacks effective drugs and treatments. ”The lack of effective and widely applicable pharmacological treatments for ischemic stroke patients may explain a growing interest in traditional medicines,” wrote Liu et al. An example is “self-medication or preventive medicine” to prevent cerebral ischemia. In this type of stroke, brain oxygen levels are too low; which can trigger a cascade of biological events leading to brain damage and death. Caterpillar fungus prevents or protects against this type of brain stroke (“ischemia-induced brain infarction”), presumably by inducing or modulating production of a steroid, 17beta-estradiol.

Cordyceps sinensis mushrooms growing out of golden caterpillar bodies are sometimes artfully and decoratively displayed in high-end Chinese herbal shops. Caterpillar fungus achieved some notoriety when it was revealed to be a dietary supplement for Chinese athletes bringing home gold and silver medals at the 2008 Beijing Olympics.

“In China, this fungus is usually called ‘Dong Chong Xia Cao,’ which means ‘Worm in winter and grass in summer,’” write Kai Yue and colleagues at Sichuan Agricultural University. “This insect parasitizing fungus lives primarily on the head of the larva of one particular species of moth, Hepialus armoricanus Oberthur (Lepidoptera), but is occasionally found growing on other moth species. Cordyceps was first introduced to Western society during the 17th century. In 1878 Saccardo, an Italian scholar, named Cordyceps derived from China officially as Cordyceps sinensis (Berk.) Sacc., and this nomenclature has been adopted up to the present day.”

At a Nepal Overseas Entomologists members symposium at the Entomological Society of America (ESA) annual meeting in Nov. 2012, at the Convention Center in Knoxville, Tennessee, Bhishma Subedi of the Asia Network for Sustainable Agriculture and Bioresources (ANSAB) screened a 20-30 minute documentary film as part of a talk titled, “Cordyceps sinensis a natural viagara(sic) from the mountains of Nepal.” Even the other Nepali entomologists in attendance learned something new, as the caterpillar fungus is found only in remote Himalayan Mountain locales; and it is not common knowledge, even in Nepal.

Known in Nepal by its Tibetan name, yarsagumba, caterpillar fungus is well-hidden; blending like a camouflaged black joss stick into black soils and grasses on slightly north-facing (5-10 degrees) Himalayan slopes 3,200 to 4,500 meters (10,500 to 14,800 ft) high. Yarsagumba lands are several days trek from anyplace where people normally live, and the ground is covered in snow 6 months of the year. But this is where temporary high-mountain camps must be set up for hunting the difficult-to-find caterpillar fungus.

Searching for the camouflaged black and debris-covered yarsagumba means crawling on hands and knees or bending over among short grasses and melted snow. Men search for yarsagumba and other medicinal herbs in the vicinity, while women stay behind and maintain the base camps. A certain Buddhist purity is maintained in yarsagumba lands; there is no alcohol, no tobacco and no shouting, loud voices or arguing. People pray, and the first yarsagumba found is offered to the Gods.

The beauty of the mountains belie the harshness of the climate and the difficulty of the life in search of yarsagumba; it’s a tough way to earn money in these remote mountains where economic opportunities are few. Storms can come at any time, and it is easy to fall down a steep cliff when climbing in the snow. A fall near a cliff edge can mean loss of limbs and frequently death. There are no second chances, no safety nets to catch you up here. Medical treatment is do-it-yourself, by necessity. Conventional medicine and doctors are many days distant. Widows are commonplace at all ages; and many subsistence families in Nepal have lost husbands, fathers, brothers and sons during the search for yarsagumba and medicinal herbs that may help others prevail against brain strokes and other maladies.

It takes seven cleanings with a toothbrush to remove all the debris and black soil, and make the black yarsagumba look like a proper insect, namely a golden caterpillar. The going price from the middlemen is 80,000 rupees per kilo; with 3,500 to 4,000 pieces of clean golden caterpillars per kilo. It takes five people a month to find a kilo. People are doing well to come out of the season with 60,000 rupees, before the expenses of the trek and weeks or months of camp costs. Recently, the Nepal government imposed a 20,000 rupee per kilo tax or royalty on the trade.

After being steamed and packaged, most of the yarsagumba eventually is exported and finds its way to the Chinese market. The yarsagumba trade is estimated at 2 tons annually. But in Nepal, since the government-imposed 20,000 rupee/kilo royalty or tax went into effect, it was like the yarsagumba harvest had become illegal for Nepal’s subsistence mountain people. Royalties were paid on only 3 kilos in a recent year. Perhaps there is a free market and tax lesson in all this. Or perhaps it is just part of the great wheel of life.


Carbon Dioxide Gas Combats Bed Bugs

July 24, 2012

CARBON DIOXIDE GAS, an essential nutrient for photosynthesis and the human and animal food chain consuming green plants, can also play a key role in bed bug control. As an attractant, carbon dioxide (CO2) is useful for monitoring and trapping bed bugs and other vampire-like blood-suckers attracted to the gas, including ticks, mosquitoes, and assorted biting flies. Carbon dioxide gas, which has been used to fumigate everything from stored grain and food products to freight containers, museum collections, and hotel and motel rooms, can also be used to fumigate clothing, furnishings, books, electronics, and other bed bug-infested items.

Carbon, carbon dioxide, and the carbon cycle are integral to our very existence on planet Earth. “The carbon of the Earth comes in several forms,” writes University of Cambridge chemist John Emsley in his fascinating Oxford University Press book, Nature’s Building Blocks (An A-Z Guide to the Elements). “Most of what we eat –carbohydrates, fats, proteins and fibre – is made up of compounds of carbon…most ingested carbon compounds are oxidized to release the energy they contain, and then we breathe out the carbon as carbon dioxide. This joins the other carbon dioxide in the atmosphere, from where it will again be extracted by plants and become part of the carbon cycle of nature…The cycle rules the tempo of life on Earth and turns over 200 billion tonnes of carbon each year…In this way carbon is passed up the various food chains, with each recipient releasing some as carbon dioxide, until most carbon is back where it started.”

Does this mean that using carbon dioxide for bed bug control is environmentally acceptable, since it is kind of a “miracle of life” gas behind photosynthesis and plant life? Or is carbon dioxide really more the evil greenhouse or global-warming gas causing global climatic havoc and deserving of punishment via carbon taxes and elimination from the atmosphere via geological carbon sequestration (storage) schemes? Perhaps we should offset carbon dioxide releases for bed bug pest control with offsetting carbon dioxide injections into greenhouses, where elevated CO2 levels increase yields of greenhouse roses, tomatoes, cucumbers, peppers and other crops.

“Carbon is probably the most important element from an environmental point of view,” writes Emsley in Nature’s Building Blocks. “The Earth’s early atmosphere may have contained a lot of carbon dioxide and methane, but once life evolved that began to change. Today, there is very little of these gases and a lot of oxygen instead, thanks chiefly to the action of plants which convert carbon dioxide and water into carbohydrate and oxygen by photosynthesis. The Earth’s atmosphere contains an ever-increasing concentration of carbon dioxide and carbon monoxide, from fossil fuel burning, and of methane, from paddy fields and cows. Human contributions to these sources are still minor compared with natural sources: most carbon dioxide comes from plants, microbes and animals, while methane is given off by swamps, marshes and termite mounds.”

Obviously best to avoid bed bug infestations, and not have to think about remedies like carbon dioxide trapping or fumigations. Italian chemist Primo Levi makes the most persuasive literary argument: “Carbon dioxide, that is, the aerial form of carbon…this gas which constitutes the raw material of life, the permanent store upon which all that grows draws, and the ultimate destiny of all flesh, is not one of the principal components of air but rather a ridiculous remnant, an ‘impurity,’ thirty times less abundant than argon, which nobody even notices. The air contains 0.03 percent; if Italy was air, the only Italians fit to build life would be, for example, the 15,000 inhabitants of Milazzo in the province of Messina. This, on the human scale, is ironic acrobatics, a juggler’s trick, an incomprehensible display of omnipotence-arrogance, since from this ever renewed impurity of the air we come, we animals and we plants, and we the human species, with our four billion discordant opinions, our millenniums of history…”

Bed bugs concern themselves little with environmental correctness, and just tune into characteristics like the heat and carbon dioxide released by metabolizing warm-blooded meal hosts like humans, poultry, rodents, rabbits, etc. A flush from a CO2 cartridge is enough to flush bed bugs from their harborages or hiding places onto a bed in search of a meal. But more naturally, bed bugs follow CO2 gradients to locate live hosts for their blood meals.

“Carbon dioxide has been shown by several researchers to be the most effective attractant for bed bugs,” University of Florida-Gainesville entomologist Philip Koehler told a recent Entomological Society of America (ESA) annual meeting. Humans produce about 700 mg (0.02 oz) of CO2 per minute. “Thus, detectors with very slow CO2 releases cannot compete with human hosts,” said Koehler. “A rapid CO2 release is a better mimic to the human breathing pattern. Detectors with fast CO2 release captured about 4x more bed bugs than detectors with slow release.”

Trapping or monitoring bed bugs with CO2 is complicated by the fact that at different times in the life cycle bed bugs seek out hosts (releasing CO2) for blood meals when hungry; and then when well-fed, instead of CO2 bed bugs seek shelter in groups or cracks and crevices. So although CO2 is the better lure for hungry bed bugs, bed bugs that have fed have different needs and respond to different lures.

A commercial product, FMC’s Verifi(TM) trap, is a dual-action detector combining “fast CO2 generation with liquid kairomone and pheromone lures to attract both host-seeking bed bugs and aggregation-seeking bed bugs,” Koehler told the ESA. Carbon dioxide and the kairomone lure blood-seeking bed bugs into a pitfall part of the trap from which there is no escape. A pheromone lures harborage- or aggregation-seeking bed bugs seeking shelter in cracks and crevices into another part of the trap.

“An inexpensive detector that can be left in place and routinely serviced is needed to aid pest management professionals,” Ohio State University’s Susan Jones told the ESA. “Rutger’s do-it-yourself dry ice (frozen CO2) traps are a cheap and effective method for overnight surveys of potentially infested habitations.” An experiment in a 13-story high-rise apartment building in Columbus, Ohio compared (see You Tube video) 3 Verifi(TM) bed bug detectors per room with 1 CO2-generating dry ice trap per room and canine (dog) detection teams (2 dogs/room; same handler).

Verifi(TM) traps detected bed bugs in 11 of 17 infested rooms in the first 24 hours; and in 14 of 17 infested rooms within a week. Dry ice traps had similar efficacy. Dogs detected bed bugs in 19 rooms, including 3 rooms where neither visual inspections nor dry ice or Verifi(TM) traps detected anything. But the dogs were also not perfect, as each dog also missed 1 room rated positive for bed bugs. So the quest to capture bed bugs with carbon dioxide and other lures goes on.

Human ingenuity seems almost unlimited when it comes to traps. Carbon dioxide, heat and other attractants are all being tested with traps as varied as Susan McKnight Inc.’s Climbup bed bug trap and pitfall traps made from inverted dog bowls painted black on the outside. Rutgers’ Narinderpal Singh tested CO2, heat, and lures such as nonanol, octanol, 1-octen-3-ol, coriander, and spearmint with inverted dog bowl pitfall traps. CO2 had an additive effect with multiple-component lures in inverted dog bowl traps, and may be developed into an inexpensive monitoring system for detecting low levels of bed bugs. Trials with baited traps are continuing.

Both carbon dioxide and ozone show fumigant potential against bed bugs. Purdue University’s Kurt Saltzmann told the ESA of “Two devices capable of delivering ozone to laboratory fumigation chambers.” One device delivered a short exposure to high ozone levels, and the other long exposure to low ozone levels. “Preliminary experiments showed that adult male bed bugs were susceptible to relatively short periods of ozone exposure when high concentrations of ozone were used,” said Saltzmann. “100% mortality was achieved when bed bugs were exposed to 1800 ppm ozone for 150 minutes.” Low ozone fumigation is also being tested with 1-2% hydrogen peroxide for up to 72 hours.

Carbon dioxide (CO2) is used by libraries, museums, and others as an insect-killing fumigant. Indeed, dry ice (frozen CO2) to release CO2 gas is cheaper than washing and drying fabrics to kill bed bugs, Rutgers University’s Changlu Wang told the ESA. At an 80% concentration, CO2 kills all bed bug eggs in 24 hours (eggs are the toughest bed bug life stage to kill). A 50% CO2 concentration for 8 hours is sufficient to kill bed bug nymphs (immatures) and adults.

Wang’s CO2 fumigations involved filling Husky garbage bags 90% full of items such as mattress covers and fabrics, leaving little room for air. Then the bags were sealed with dry ice inside for several hours. Books, electronics, toys and other items damaged by heat treatments might benefit from the low temperatures created by dry ice treatments. However, for safety reasons Wang recommends wearing gloves and turning on fans for ventilation when opening many bags filled with carbon dioxide gas (fumigant).


An Eco-Organic Ode to Ethanol (Ethyl Alcohol)

June 6, 2012

ETHANOL, AN ANCIENT DISINFECTANT commonly used in today’s medical and health-care hand sanitizers, is also produced by microbes in food fermentation and natural ecosystems. A simple two-carbon molecule abbreviated EtOH by chemists, ethanol (ethyl alcohol) is also routinely used in organic chemistry and commerce as a solvent for natural essences or tinctures like perfumes, food flavorings, and medicinals.

“By far the most common natural source of ethanol is fermentation of fruit sugars by yeasts,” wrote Douglas J. Levey in The Evolutionary Ecology of Ethanol Production and Alcoholism, an article in Oxford Journals’ Integrative & Comparative Biology. “Although ethanol is an end product of fermentation, the fungi that produce it are locked in a complex set of interactions with fruiting plants, frugivorous vertebrates, and other microbes. Given that ethanol affects both vertebrates and microbes, it is likely to have at least some adaptive basis. In particular, it may be viewed as a defensive agent, used by yeasts to inhibit growth of competing microbes in much the same way as penicillin is thought to give Penicillium fungi the upper hand in competition with bacteria.”

“In an anthropological context, fermentation can be viewed as controlled spoilage of food,” wrote Levey. “The microbes responsible for the later stages of food spoilage generally cannot grow in alcoholic or acidic environments. Thus, by culturing the production of alcohols and in many cases organic acids via limited exposure to oxygen, the food is protected. Long before refrigeration and synthetic additives, fermentation was one of the most important food preservation technologies… As they discovered the inebriating qualities of some fermented foods, they focused attention on those fermentative processes, ultimately leading to the beer and wine industries of today.”

Ethanol and fermentation are part of fruit plant reproductive ecology. Ethanol molecules multi-task: Fruit pulp is protected from microbial decay by ethanol. Ethanol also attracts fruit pulp-eating (frugivorous) animals aiding plant reproduction via seed dispersal. In essence, fruit pulp is redirected in the ecological food chain from microbes to higher animals, to the benefit of fruit plant reproduction.

“The low molecular weight of ethanol and its substantial concentration within fruit pulp well suit this molecule for long-distance signaling of availability to appropriate consumers,” wrote Robert Dudley in an article titled Ethanol, Fruit Ripening, and the Historical Origins of Human Alcoholism in Primate Frugivores in a 2004 issue of Integrative & Comparative Biology. “Ripening involves production of a number of fruit volatiles, but ethanol is perhaps the only olfactory commonality to an otherwise bewildering taxonomic array of angiosperm fruits.”

“As with longevity and fitness benefits of ethanol exposure in fruit flies, epidemiological studies in modern humans demonstrate a reduction in cardiovascular risk and overall mortality at low levels of ethanol consumption relative either to abstinence or to higher intake levels,” writes Dudley. “If natural selection has acted on human ancestors to associate ethanol with nutritional reward, then excessive consumption by modern humans may be viewed as such a disease of nutritional excess. Availability of ethanol at concentrations higher than those attainable by yeast fermentation alone (i.e., 10–12%) is a very recent event in human history.”

Underscoring the importance of ethanol in ecosystems, yeast fungi survive up to 15% (v/v) ethanol concentrations that are lethal to most microbes. Distillation, a technique known to ancient alchemists that survived the transition from magical potions to modern chemical science, of course boosts ethanol concentrations to much higher and more lethal/toxic levels than those found in natural ecosystems.

Ethanol is also an ecological feedstock. Yeasts and certain bacteria further transform (oxidize) ethanol into acetic acid or vinegar, which besides being culinary is toxic to many microbes. In India and elsewhere, anti-microbial solutions of vinegar and baking soda commonly replace harsh commercial chemicals for floor and surface cleaning.

Ethanol’s role as an animal attractant can be turned to human advantage: for example, in ecological pest control as part of traps or trap crops. Christopher Ranger and Michael Reding of the USDA-ARS in Wooster, Ohio, and Peter Schultz, Director of Virginia Beach’s Hampton Roads Agricultural Research and Extension Center told the Entomological Society of America (ESA): Ethanol released by stressed (e.g. lack of water) or doped (injected with ethanol) forest or nursery trees (e.g. magnolias) attracts ambrosia beetles (Xylosandrus species). “A successful trap crop strategy might include 75ml (2.5 fl oz) of 90% ethanol injection of cull or park grade trees of an attractive species within the field production block or along the border between a woodlot and the high value nursery crop species,” said Schultz.&&

In the USA, where the federal government controversially subsidizes corn ethanol and mandates its use as a fuel, Douglas Landis and University of Illinois-Urbana colleagues Mary Gardinera, Wopke van der Werf and Scott Swinton wrote of the deleterious ecological consequences of growing too much corn in a 2008 issue of the Proceedings of the National Academy of Sciences of the USA. In contrast to intercropping strategies promoting landscape diversity and biocontrol of pests by natural enemies, increasingly large almost monoculture acreages of corn create a less diverse landscape with less biocontrol in other regional crops like soybeans. Too much corn in the landscape costs soybean producers in Iowa, Michigan, Minnesota and Wisconsin an estimated $239 million in reduced yields and increased pest control costs.

Not that planting corn need be bad. Indeed, the Native Americans traditionally interplanted corn with squash, beans, strawberries, sunflowers, and diverse weedy species that promoted ecological balance between pests and natural enemies. “Biological control of insects is an ecosystem service that is strongly influenced by local landscape structure,” wrote Landis et al. “Altering the supply of aphid natural enemies to soybean fields and reducing biocontrol services by 24%” from planting too much corn cost an estimated $58 million in soybean crop loss and control costs for just one pest, the soybean aphid.

Distiller’s dried grains (DDGs) leftover from ethanol production could potentially be utilized in innovative ways. Though with billions of gallons of corn ethanol being distilled, the emphasis is understandably on utilizing big tonnages of DDGs for animal feed, mulches, etc., rather than really innovative research that could yield niche corn-based products for medical use. Yiqi Yang, a Professor of Biological Systems Engineering and Charles Bessey Professor in the Nebraska Center for Materials and Nanoscience and the Departments of Biological Systems Engineering and Textiles, Clothing and Design at the University of Nebraska-Lincoln, believes that small research investments could yield niche innovations like medicines (e.g. corn-derived cancer-fighting molecules small enough to enter the brain) and biodegradable filters that can be left in the human body.


Fruit Flies, Ethanol, Good Health & Biocontrol

March 19, 2012

SEXUAL DEPRIVATION INCREASES Ethanol Intake in Drosophilia” was the semi-tabloid headline in the American Association for the Advancement of Science (AAAS) journal Science (16 March 2012; v. 1355, p. 1351). No fools, the AAAS knows a scientific title readily translatable into good headlines and writerly fun; parental Internet filters be damned. I was particularly impressed by Scientific American Science Sushi blog writer Christie Wilcox’s entertainingly deft mix of science, human implications and fun stuff on fruit flies with quotes from lead scientist Gilat Shohat-Ophir.

You Tube has an entertaining mix of titles on the subject, such as: 1) Flies turn to drinking after sexual refusal; 2) Study: Rejected Male Flies Turn to Alcohol; 3) Scientists Find Fruit Flies Self Medicate With Booze; and from Emory University, 4) ‘Drunken’ fruit flies use alcohol as a drug. The underlying science has a certain fascination, as there are similar neural (molecular) pathways for rewards and addiction (and their interaction with social experiences) in the two species: neuropeptide F (NPF) in fruit flies and neuropeptide Y (NPY) in humans. “Flies exhibit complex addiction-like behaviors,” write Shohat Ophir and colleagues K.R. Kaun, A. Azanchi and U. Heberlein, including “a preference for consuming ethanol-containing food, even if made unpalatable.”

In primitive natural settings, ethanol from fermentation of overripe fruit functions as a cue or lure for humans, fruit flies and other animals to locate fruit crops. Indeed, there is evidence that fruit fly larvae “have evolved resistance to fermentation products” from millennia of eating “yeasts growing on rotting fruit.” But fruit flies are not immune to alcohol-related mortality; the dose of the poison (alcohol) determining whether it is medicinal.

“The high resistance of Drosophila melanogaster (fruit fly) may make it uniquely suited to exploit curative properties of alcohol,” wrote Emory University’s Neil Milan, Balint Kacsoh, and Todd Schlenke in an article titled “Alcohol Consumption as Self-Medication against Blood-Borne Parasites in the Fruit Fly” in Current Biology (2012). “Ethanol levels found in natural D. melanogaster habitats range up to 6% ethanol by volume in rotting fruits, and 11% in wine seepages found at wineries. Fly consumption of food with moderate levels of ethanol (i.e., less than 4% by volume) results in increased fitness, but consumption of higher ethanol concentrations (i.e., greater than 4%) causes increasing fly mortality.”

One of the hazards of life for fruit flies is parasitic wasps, which sting the flies and lay eggs hatching into parasitoid larvae living inside and eventually killing the fruit fly. From the fruit fly’s perspective, biological control by natural enemies is deleterious and best prevented or overcome. “We have shown here that ethanol provides novel benefits to flies by reducing wasp infection, by increasing infection survival, and by allowing for a behavioral immune response against wasps based on consumption of it in toxic amounts,” wrote Milan and his colleagues. “To our knowledge, these data are the first to show that alcohol consumption can have a protective effect against infectious disease and in particular against blood-borne parasites. Given that alcohols are relatively ubiquitous compounds consumed by a number of organisms, protective effects of alcohol consumption may extend beyond fruit flies. Although many studies in humans have documented decreased immune function in chronic consumers of alcohol, little attempt has been made to assay any beneficial effect of acute or moderate alcohol use on parasite mortality or overall host fitness following infection.”

Scientists and students with science projects have been rearing fruit flies for over a century, and unraveling many of the mysteries of biological life. Indeed, the common fruit fly, “Drosophila melanogaster is emerging as one of the most effective tools for analyzing the function of human disease genes, including those responsible for developmental and neurological disorders, cancer, cardiovascular disease, metabolic and storage diseases, and genes required for the function of the visual, auditory and immune systems,” wrote Ethan Bier of the University of California, San Diego, in Nature Reviews Genetics (v.6, Jan. 2005). Depending on the matching criteria, anywhere from 33% to “75% of all human disease genes have related sequences” in fruit flies. Thus, “D. melanogaster can serve as a complex multicellular assay system for analysing the function of a wide array of gene functions involved in human disease.”

Something to think about next time you see those tiny (1/8 inch; 3 mm) golden or brownish fruit flies flitting around your overripe bananas, vegetable-laden bins and garbage cans.


Asian Innovations in Insect Control

August 20, 2011

Innovations in Insect Control in Asia date back almost 2,000 years to when ancient Chinese farmers learned the art of biological insect control. China’s ancient orchardists annually introduced colonies of predatory ants to cultivated trees to control caterpillars and other pests of crops such as citrus. Ancient Chinese biocontrol practices included constructing bamboo bridges between trees, so predatory ants could easily wander from tree to tree foraging for pests.

Fast forward to the twenty-first century: Tea is arguably the second most widely consumed beverage, after water. Tea production occupies 2.7 million ha (6.7 million acres) in 34 countries, with 78% of production in Asia and 16% in Africa. Sustainable tea production practices emphasize displacing pesticides with cultural and biological control practices to control spider mites and other pests in tea plantations.

“The application of natural enemies in tea pest control aroused a large amount of investigations in the tea producing countries,” reported Yang Yajun and colleagues at the Tea Research Institute of Chinese Academy of Sciences at the 2005 International Symposium on Innovation in Tea Science and Sustainable Development in Tea Industry. “In South India, investigations showed the introduction of three species of entomophagous fungi in the control of tea spider mite (Oligonychus coffeae). In Japan, the use of pesticide-resistant predatory mite resulted in successful control…In Japan, one fungal preparation and one bacterial preparation were registered and used in control of tea diseases.” In China and Japan, viruses stop pesky leafrollers and loopers. Japan also has five fungal biocontrol products, one bacterial biocontrol preparation, and several kinds of parasitic and predatory natural enemy preparations to control tea insect pests.

“Great achievements in the application of physical and agricultural control methods in controlling the tea pests were advanced,” said Yajun et al. In Japan, China, and Malawi (Africa), yellow sticky traps and reflective films (near ultra-violet light) help control tea aphids, thrips, and leafhoppers (70-80% pest reduction). “A special mist wind insect-sucking machine was developed in Japan,” and it reduces tea leafhopper, whitefly, and spider mite populations.

Sex pheromones have been used for mating disruption in Japanese tea gardens since 1983 to control a pesky tea leafroller. Sex pheromones are also being used against other tea pests in Japan and China. Natural volatiles from the tea plant that attract natural enemies but not pests are also under development. For example, the April 2004 Chinese Journal of Applied Ecology (15(4):623-626) reported that beneficial lady beetles, green lacewings, and hover flys (syrphids) controlling tea aphids were attracted by natural compounds such as nerol from tea flowers, n-octanol from intact tea shoots, and geraniol, methyl salicylate, benzaldehyde, and hexanal from aphid-damaged tea shoots.

At Entomological Society of America (ESA) annual meetingss, California Department of Food and Agriculture (CDFA) officials report that T. Kanzawa’s 1939 translation of Professor Dr. Shonen Matsumura‘s 1931 book, 6000 Illustrated Insects of Japan-Empire, is still used to help with identification and control of invasive insect pests like the dusky-winged fruit fly (Drosophila suzukii). Oregon entomologist Jana Lee told the ESA that the Japanese get 100% fruit fly protection by placing 0.98 mm (0.04 inch) mesh over blueberries 20 days pre-harvest. After the harvest, 100% of fruit fly eggs and newly hatched larvae on cherries are killed by holding the fruit at 1.6-2.2 C (29-36 F). In Japanese experiments, fruit fly egg laying in cherries was reduced 30-60% with botanicals such as eucalyptus, neem, and tansy. In other promising Japanese research, Kotaro Konno and Hiroshi Ono told the ESA that latex from the same mulberry leaves used to safely grow silkworms since ancient times could be an effective botanical insecticide against other pests.

Since the 1920s, the USDA has been importing Japanese and Korean biocontrol organisms, like Tiphia wasps to control Oriental beetles and Japanese beetles attacking golf courses, turf, crops, and landscape ornamentals. Japan is currently patenting decoy tree technologies to help stop an explosive outbreak of oak wilt fungus (Raffaelea quercivora), caused by mass attacks of ambrosia beetles (Platypus quercivorus), said Masahiko Tokoro of the Forestry and Forest Products Research Institute (FFPRI) in Ibaraki, Japan (See earlier blog post: The Asian Invasion -Insects in Global Trade).

In South Korean greenhouse tests, Sangwon Kim and Un Taek Lim of Andong National University told the ESA of greenhouse tests showing the superiority of yellow circles against a black background versus conventional rectangular yellow sticky traps for capturing pesky whiteflies and thrips. “In laboratory behavioral studies using different backgrounds and shapes, yellow sticky card with black background was 1.8 times more attractive than sticky card without background, and triangle attracted 1.5 times more sweetpotato whitefly (Bemisia tabaci) than square,” said Kim. Black sticky cards with small yellow circles caught 180% more sweetpotato whitefly than cards with larger circles.


Honey Bees, 24-Hour Surveillance Cameras & Pesticides

February 22, 2011

HONEY BEE HEALTH had the entomologists buzzing and the grad students searching for answers at the Entomological Society of America (ESA) annual meeting in San Diego. For several years now specialists have been spinning speculative theories as to why the pollinating honey bees of commerce, mostly the species known as Apis mellifera, have been in such sad shape. Isaac Newton had the proverbial apple bonk him awake to gravity. Bee entomologists have not yet had that magical bee sting in the butt “Aha” moment.

But there seems no getting away from the problem, as keepers of bee hives an ocean away from the USA are also getting stung with big losses, from what is dubbed colony collapse disorder (CCD). What has entomologists scurrying to their Petri dishes and bee hives and firing up surveillance cameras, chromatographs and mass spectrometers is a study titled “High Levels of Miticides and Agrochemicals in North American Apiaries: Implications for Honey Bee Health.” Christopher Mullin of The Pennsylvania State University, a self-described connoisseur of how poisons work, and several colleagues “found 121 different pesticides and metabolites within 887 wax, pollen, bee and associated hive samples” from 23 states and one Canadian province. Enough to induce sleep-loss and second thoughts about the health and sleep-inducing effects of commercial honey products.

Surveillance cameras, 24-hours a day, are the best way to monitor and gather numerical data on how pesticides affect honeybees, Cornhusker grad student Bethany Teeters told the ESA in her prize-winning poster, “Bees under surveillance.” Being more video than even an insomniac can sanely watch, the University of Nebraska-Lincoln entomology lab delegates the task to “state-of-the-art detection” software: namely EthoVision XT, which Noldus Information Technology calls “the most widely applied video tracking software that tracks and analyses the behavior, movement, and activity of any animal” from “lab animals in mazes to farm animals in stables.” No doubt what Geoge Orwell would have used in his Animal Farm novel, had he written it in 2011 rarther than 1946.

“Honey bees are exposed to sublethal doses of pesticides on a regular, often chronic, basis,” Teeters told the ESA. “For instance, the pyrethroid tau-fluvalinate (Apistan(R)) is one of many pesticides applied directly into the hive to control the parasitic mite Varroa destructor. Although tau-fluvalinate is considered safe for honey bees, potential effects of sublethal intoxication remain unexplored.” Same goes for coumaphos, also used to treat for Varroa mites.

“Honey bees may also encounter sublethal doses of pesticides while foraging,” said Teeters. “Systemic pesticides, including the neonicotinoid imidacloprid, have become prominent in U.S. crop pest management. This raises concerns about the consequences of sublethal exposure to systemic pesticides in nectar and pollen that honey bees visit in addition to chronic exposure to residues in the hive. Decline in colony health has been associated with ppm (parts per million) pesticide residues in hive products, and the neonicotinoid can impair honey bee health at ppb (parts per billion) levels.”

Teeters surveillance videos of bees exposed to sublethal pesticide doses in Petri dishes revealed that bees exposed to tiny traces of tau-fluvalinate spend more time socially interacting. Bees exposed to imidacloprid spend less time socially interacting and more time eating. Next step is studies to see if this is true in actual honey bee hives, and whether colony health is impacted.

Natalie Boyle, a graduate student at Washington State University in Pullman, studied the effects of Varroa mite pesticides on honey bee hives in Moscow, Idaho. Honey bee adults stressed by miticide residues died sooner and did less reproductive swarming. But they compensated with increased brood production. “While our results are preliminary, if we find that pesticide residues in brood comb adversely affect colony health, it would suggest that regular brood comb replacement in beekeeping operations might be a suitable management strategy,” said Boyle. “Similarly, approaches to reduce miticide applications in beehives and pesticide exposure in agricultural field settings would be highly beneficial.”

Back at The Pennsylvania State University, graduate student Daniel Schmehl noted that the Varroa mite-killing chemicals coumaphos and tau-fluvalinate were found in almost every honey bee hive sampled in North America. Furthermore, these two chemicals were “associated with reduced queen weight and reduced ovary development.” After six days chronic exposure to tau-fluvalinate in cage studies, worker bees were less attracted to queen bees. This was possibly “due to changes in pheromone production from the queen or pheromone recognition by the workers.”

On the West Coast, at the University of California, San Diego, graduate student Daren Eiri explored how sublethal doses of the pesticide imidacloprid can subtly alter foraging habits in ways that weaken honey bee colonies. A common lab assay used to assess foraging is stimulating the honey bee antenna with sucrose, which elicits the proboscis (tongue) extension reflex (PER). PER is the lab equivalent of natural honey bee behavior in the field when foragers are stimulated by nectar. The pesticide seemed to make the bees “become pickier when foraging for nectar sources, possibly limiting the colony intake and storage of their only carbohydrate.” Pollen foraging may also be reduced, and “the colony would therefore suffer a protein deficit, resulting in lessened brood production and a dwindling population.”

Though the mystery of colony collapse disorder (CCD) is far from solved, current agriculture practices do not seem to be making honey bee colonies healthier, to say the least. But the collapse of the imported honey bee may have a silver lining: It is spurring agriculture to turn to previously neglected native pollinators. But the rise of the native pollinators is another story, for another time.


The Asian Invasion -Insects in Global Trade

January 8, 2011

NATURAL WOOD PRODUCTS are better than synthetic petrochemical plastics is a common refrain, almost a rallying cry for many who consider themselves “green,” organic, sustainable or environmentally correct. Thus, the fashionable zeal in some sectors of society to ban plastic shopping bags and allow wood-pulp paper bags. But what if being “green” and using natural materials like wood instead of synthetic petrochemical plastics led to deforestation and pestilence? That’s pretty much the world trade situation these days.

At first glance wood pallets, crates, dunnage, and packaging materials seem to be the low-cost, sustainable “green” alternative vis-a-vis more expensive, synthetic petrochemical plastics. But wood packing materials used in global trade have spread a pestilence of native Asian wood-boring beetles to new homes worldwide. The North American invasion by Asian wood-boring species of bark beetles, ambrosia beetles, and long-horned beetles were among the hot topics at the Entomological Society of America (ESA) annual meeting of Dec. 2010 in San Diego, California.

Since hitchhiking to North America from Asia in solid wood packing materials and being detected near Detroit, Michigan in 2002, the wood-boring emerald ash borer has killed an estimated 30 million ash trees in the northern United States and southern Canada. The remaining North American ash trees are threatened. Though Sara Tanis, whose Michigan State University work is on You Tube, reported at the ESA annual meeting that blue ash (Fraxinus quadrangulata) “can withstand infestation and continue to survive.”

Emerald ash borer control is now multinational, involving the U.S. states of Michigan, Illinois, Indiana, Iowa, Kentucky, Maryland, Minnesota, Missouri, New York, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia, and Wisconsin plus the Canadian provinces of Ontario and Quebec. The Asian wood-boring beetle invasion is so far along it might make little difference if world trade abandoned wood pallets, crates, dunnage, and packing materials.

“Control strategies are now shifting to how we can manage established populations in the longer term,” Shajahan Johny of the Canadian Forest Service Great Lakes Forestry Centre in Sault Ste. Marie, Ontario, Canada, told the ESA. “One possibility is biological control, which is recognized as the most suitable long-term pest management strategy for invasive species.” Johny is looking at fungi in the genera Isaria and Paecilomyces attacking emerald ash borer in Ontario.

In Michigan and Ontario, Canada, the early emerald ash borer hot spots, woodpeckers can peck out up to half the wood-borers; which is good for the birds, but not stopping beetle movement to new trees. “In their native habitats, Agrilus (sci name of genus of 3,000 wood-boring beetles) populations are generally suppressed by a diverse group of natural enemies and/or host tree resistance, and rarely become serious pests,” said Jian Duan, Lead Scientist of the emerald ash borer biological control team at the USDA-ARS Beneficial Insects Introduction Research Unit in Newark, Delaware. The USDA has searched Russia, Mongolia, China, and South Korea to find specialized parasitoids that can be introduced to North America to hunt wood-boring beetle eggs concealed under loose bark and larvae hidden inside trees. The idea being to restore a natural ecological balance.

Asia has not been immune to wood-boring beetle outbreaks. “The mass mortality of oak trees (Japanese oak wilt) has recently increased explosively in Japan,” Masahiko Tokoro of the Forestry and Forest Products Research Institute (FFPRI) in Ibaraki, Japan, told the ESA. The Japanese are using a Decoy Tree Method (patent pending). Trap trees are baited with an aggregation pheromone attracting the wood-boring oak ambrosia beetle (Platypus quercivorus). Ethanol (alcohol) is added to the mix, because it is emitted by unhealthy or stressed trees and attracts beetles.

“Oak trees survive when they have been inoculated with a fungicide against the pathogenic fungus (oak wilt) before being attacked,” said Tokoro. “The decoy trees are lethal to the beetles because the symbiotic fungi (i.e. the ambrosia) that the beetles feed on are killed by the fungicide.” Neighboring trees can be similarly protected.

Variations on this method called push-pull are being developed in the U.S. to protect nursery trees from exotic ambrosia beetles (Xylosandrus spp.), said Christopher Ranger of the USDA-ARS Application Technology Research Unit in Wooster, Ohio. Ethanol is injected into sweetbay magnolia trap trees to stimulate ambrosia beetle attack. Beetles are “pushed” out of trees being protected by application of a repellent compound such as verbenone (dispensers) or via commercial botanical repellents such as Armorex, Veggie Pharm, Cinnacure. Azatin or Eco-Trol.


Richard Feynman’s Nontoxic Ant Ferry

June 2, 2010

RICHARD FEYNMAN, CALTECH’S Nobel Prize winning physicist (1965; quantum electrodynamics), was a Princeton University graduate student during the early years of World War II when foraging ants crawled in his bay window and spurred development of an ant control device that did not kill the creatures. It was not quite as momentous as the proverbial apple conking Isaac Newton on the head in 1666 and waking him up to gravity. But according to Mathpages.com, Feynman’s “analysis of the behavior of ants involves some of the same ideas that were central to his work in theoretical physics.”

On a more mundane note, Feynman recounts the experience in his 1985 book, Surely You’re Joking, Mr. Feynman!: “In Princeton the ants found my larder, where I had jelly and bread and stuff, which was quite a distance from the window. A long line of ants marched along the floor across the living room. It was during the time I was doing these experiments on ants, so I thought to myself, ‘What can I do to stop them from coming to my larder without killing any ants? No poison; you gotta be humane to the ants!'”

Interesting sentiments coming from a man who worked on the Manhattan Project in New Mexico to help develop atomic energy into the bombs dropped on Japan to end World War II. But, of course, the goal of the Manhattan Project was to build the bomb ahead of Hitler’s scientists working in Europe. Peace and freedom were envisioned at the end of the atomic trail.

“One question that I wondered about was why the ant trails look so straight and nice,” wrote Feynman in his oft-reprinted 1985 book. “The ants look as if they know what they’re doing, as if they have a good sense of geometry. Yet the experiments that I did to try to demonstrate their sense of geometry didn’t work. Many years later, when I was at Caltech and lived in a little house on Alameda Street, some ants came out around the bathtub. I thought, ‘This is a great opportunity.’ I put some sugar on the other end of the bathtub, and sat there the whole afternoon until an ant finally found the sugar. It’s only a question of patience.”

Today we know that ants are putting down a pheromone trail, and that over time the trails most frequented (i.e with food at the end) get a stronger dose of pheromone while the pheromone disappears from the least-wandered trails. Feynman’s observations are called Ant Logic or Ant Colony Optimization by those who, in or out of the bathtub, today study the trail-following process, oftentimes using virtual ants in computer simulations for Internet routing, robotics, and business and travel solutions.

Apparently, via pheromone trails between their nest and food resources, in their everyday life ants have mastered a workable solution to what is called The Traveling Salesman Problem, which the web site of the same name (abbrev. TSP) calls “one of the most intensively studied problems in computational mathematics.”

Planning the best route between a hundred cities for a traveling rock band or the quickest path for sending data packets among thousands of Internet nodes on the Worldwide Web can apparently overheat and exhaust modern computers. In a chapter titled “Ant Logic” in The Perfect Swarm, book author Len Fisher says: “To calculate the optimal route that Ulysses might have taken between the 16 cities mentioned in The Odyssey, for example, requires the evaluation of 653,837,184,000 possible routes.” That works out to “ten thousand billion calculations” for a relatively simple travel problem.

Fortunately, Nobel Prize-caliber calculations were not needed to disrupt ant trails and humanely protect Feynman’s Princeton larder or Pasadena home. ANT FERRY was the name Feynman gave to his least-toxic ant removal device: “I made a lot of little strips of paper and put a fold in them, so I could pick up ants and ferry them from one place to another,” wrote Feynman in Surely You’re Joking, Mr. Feynman!.

“What I did was this: In preparation, I put a bit of sugar about 6 or 8 inches from their entry point into the room, that they didn’t know about. Then I made those ferry things again, and whenever an ant returning with food walked onto my little ferry, I’d carry him over and put him on the sugar. Any ant coming toward the larder that walked onto a ferry I also carried over to the sugar. Eventually the ants found their way from the sugar to their hole, so this new trail was being doubly reinforced, while the old trail was being used less and less. I knew that after half an hour or so the old trail would dry up, and in an hour they were out of my larder. I didn’t wash the floor. I didn’t do anything but ferry ants.”

No Nobel Prize is needed to obliterate ant trails and naturally protect larders without toxins or even killing any ants. However, the patience, the extra hour, may be outside the modern mindset. Nonetheless, thank you Mr. Feynman for what your colleagues call a PROOF of CONCEPT.


Natural vs Synthetic Repellents

March 30, 2010

SYNTHETIC OR NATURAL? Which is best? Since the 1950s the synthetic chemical DEET (N, N-diethyl-m-toluamide) has been the standard to which all other mosquito, tick and biting fly repellents have been compared. DEET is still the standard of comparison, but the long search for natural or organic repellents is finally yielding a number of potential alternatives, some from the plant world and others from such unlikely places as human sweat.

The progress in besting DEET has been so stunning that the Entomological Society of America (ESA) presented a four-hour symposium with a dozen 20-minute talks, Celebrating the Success of Global Insect Repellent Science Research. Habitues of the ESA know that in the world view of a female mosquito, humans are little more than scented apes put on Earth to be protein-rich blood meals to begat new generations of what we call vermin and they consider kin.

Sweat, heat, and carbon dioxide, that greenhouse gas that humans respire into the atmosphere with every exhaled breath, tip off mosquitoes and other bloodsuckers that the human food wagon has arrived. Actually, that’s putting it a bit crudely. Mosquitoes are actually connoisseurs, and sniff out humans like a gourmet would a fine wine. To be even more accurate, females are the true connoisseurs and gourmands, the bloodsucking vampire sex of the mosquito world. Male mosquitoes are true flower children, pacifists abhorring the bloodsucking life and mostly passing the time pollinating plants.

Longtime scholars of mosquito feeding habits on humans, like Willem Takken at Wageningen University in The Netherlands, have tallied 300 to 350 compounds mosquitoes can use to identify humans. About 60 of these odors are common to every person, and the rest give each human a slightly different scent. Thus, we oftentimes remember a person by their distinctive smell. Elegant experimental techniques like gene silencing and transferring mosquito olfactory genes to fruit flies allows the mapping of mosquito odor preferences. Some mosquito species, such as the malaria-vector Anopheles gambiae, can zero right in on humans. Other mosquito species may bypass humans in favor of cows, livestock or other animal species.

From a practical standpoint, if diseases like malaria, dengue and yellow fever are not a concern and you need protection for only an hour or two, one of the many commercial botanical repellents is likely to suffice as an alternative to DEET. Lemon eucalyptus products, including Quwenling from China, get high marks from the CDC. Daniel Strickman at the USDA-ARS in Beltsville, MD, and others have compiled long lists of botanicals good for about an hour of repellency, including: clove, geranium (geraniol), citronella, celery, lemon, lime, neem, pyrethrum, fringed rue, patchouli, pennyroyal, soybean, thyme, niaouli (Melaleuca viridiflora), makaen (Zanthoxylum limonella), Mexican tea (Chenopodium ambrosioides), Labrador tea (Ledum groenlandicum), and lily-of-the-valley.

However, natural or organic does not automatically mean safe or lacking in toxicity. Natural compounds, like synthetics, can also be sources of skin irritation, toxicity, and carcinogenicity. Even lemon eucalyptus oil can be an eye irritant. And as some herbal tea drinkers have learned the hard way (as is documented in the medical journals), the active ingredients in pennyroyal, violets and other botanicals can be dangerously toxic in too high a dose or with prolonged use.

The U.S. EPA can give what is known in legalese as FIFRA 25(b) Exemptions (Minimum Risk Pesticides), the USDA’s Strickland told the ESA repellent symposium. This allows some natural compound active ingredients to be used as repellents without testing. Examples include cedar oil (from eastern red cedar), citronella, garlic, geranium, lemongrass, peppermint, soybean oil and thyme. The International Fragrance Association investigates active ingredients to avoid lawsuits over cosmetics, though even this is not a guarantee against allergic reactions.

In short, caution is the watchword. Try a little bit first, and to be really safe use long sleeves and pants so that minimal repellent directly contacts the skin (as both natural and synthetic chemicals may penetrate the skin and enter the bloodstream).

Joel Coats’ lab at the University of Iowa provided the ESA symposium with a glimpse of the future. Coats’ lab is well-known in entomological circles for its pioneering work with naturally occurring monoterpene and sesquiterpene chemicals in plants such as catnip (Nepeta cataria), Osage orange (Maclura pomifera), West Indian sandalwood (Amyris balsamifera), and Siam-wood (Fokenia hodginsii). In short, the chemicals known as monoterpenes provide a broad spatial repellency, and the “oxygenated sesquiterpenes” provide contact repellency. And a mixture of the two provides both modes of action and the best repellency. You will probably want to wait for the testing to be completed and commercial products to be formulated.

But back to the question of which is best, natural or synthetic. Some of the best natural compounds, and there are too many to list, can outperform DEET. Even some new synthetics can outperform DEET in some ways. If you have a job that keeps you in the field and exposed to mosquitoes, biting flies and ticks for 12 or 24 hours at a time, then you need some heavy-duty, long-lasting protection. Indeed, that is the holy grail for organizations like the U.S. Army.

Life may have seemed simpler in the 1960s when Mr. Robinson told Dustin Hoffman in the movie The Graduate that the future was in plastics. Quantitative structure-activity relationships (QSAR) is the future in 2010, say Coats and his graduate student Gretchen Paluch. They forsee a leapfrogging future where natural repellents better than DEET lead to new synthetic spinoffs of nature’s best molecules better than anything yet known.

They believe that patchouli, cedar oil and other natural compounds can (via QSAR) provide the skeleton for designing new repellent molecules. However, it may not be so simple, as a fine ecological balance has evolved in nature. Though it may seem contradictory, even so-called repellent plants like catnip, which is famous for repellent molecules like neptalactone, also contain attractant molecules. Possibly the best repellents will also contain elements of attraction. But that is another story for another time.


Beneficial Bugs Challenge Theoretical Physics

November 8, 2009

INSECTS, MICROBES, PLANTS and other organisms form complex ecological systems with all sorts of synergisms, antagonisms and cooperative interactions, leading oftentimes to beneficial insects controlling what we consider pests. Whether it be forest, desert, farm field or garden, intricate and nuanced ecological communities can be nurtured to provide a measure of “natural” biological pest control.

The nuanced complexity of biological and ecological systems has at times intrigued theoretical physicists usually more attuned to quarks, neutrinos, chaos theory and quantum phenomena. Murray Gell-Mann, winner of the 1969 physics Nobel Prize as a Caltech (Pasadena, California) professor “for his contributions and discoveries concerning the classification of elementary particles and their interactions,” created the Santa Fe Institute (New Mexico) to better focus on “the theory of complex adaptive systems.”

Humans, plants and animals are individually and collectively at the ecosystem level examples of complex adaptive systems. Which is one reason creating sustainable agriculture is such a challenge, and companies such as Rincon-Vitova Insectaries end up with catalogs of 55 pages of beneficial insects, microbes, seeds, traps and other inputs for creating sustainable garden and farm systems. And even then, it is not always easy and can take longer than expected to force changes in even the smallest complex adaptive system that is a backyard garden.

“Unfortunately, it will be a long time before human knowledge, understanding, and ingenuity can match–if ever they do–the “cleverness” of several billion years of biological evolution,” wrote Gell-Mann in his book, The Quark and the Jaguar. “Not only have individual organisms evolved their own special, intricate patterns and ways of life, but the interactions of huge numbers of species in ecological communities have undergone delicate mutual adjustments over long periods of time.”


Pheromone Revolution Hits Half Century Mark

October 7, 2009

HALF a CENTURY ago the PHEROMONE REVOLUTION commenced in earnest. German chemist Adolf Friedrich Johann Butenandt opened the floodgates as lead author of an article announcing the isolation and chemical identification of a sex pheromone female silkworm moths produce to attract male mates. Butenandt had already shared the 1939 Nobel Prize in chemistry for discovering human reproductive steroid hormones. So the 1959 article announcing the first pheromone in the monthly chemical science journal Zeitschrift für Naturforschung B (14B:283-4) attracted the attention of Rachel Carson and stimulated the efforts and imaginations of many others searching for insecticide-reducing alternatives.

HALF a MILLION virgin female silk moths were sacrificed over a span of almost THREE DECADES to identify that first sex pheromone, named bombykol because Bombyx mori is the scientific name of the Chinese silk moth of textile fame. In the past half century, thousands more pheromones have been identified, mostly from pest insects of economic interest. But also increasingly from beneficial insects providing biological control.

According to researchers like Jeffrey Aldrich at the USDA-ARS Chemicals Affecting Insect Behavior Laboratory (CAIBL) in Beltsville, MD, the potential applications of natural enemy pheromone and semiochemical research, such as herding beneficial insects into crop fields where they are needed, is still in its infancy. Projects include using pheromones to increase biocontrol by predatory spined soldier bugs (Podisus maculiventris). These beneficial stink bugs are capable of biologically controlling pesticide-resistant Colorado potato beetles, Mexican bean beetles, and cabbage and tomato caterpillars.

One idea is using pheromones to trap natural enemies, and then creating mini-insectaries by placing cages full of natural enemies into crop fields and landscapes. Predator production can be maximized with “an in-field nursery where we are putting these trapped bugs right inside of the (mesh) cage” over plants in the field, said Aldrich. “You pick a mesh size where the adults can’t get out, but when they lay eggs then the nymphs can walk out and start feeding on pest species in the vicinity.” In field tests, potato defoliation was reduced and yield significantly increased.

In bean field tests, spined soldier bug nymphs walked upwind towards an aggregation pheromone. In sequential plantings, this technique could be used by farmers to move or herd predators out of maturing fields into more newly planted fields. Pheromone technologies are also being explored to maximize biocontrol by minute pirate bugs, big-eyed bugs, tachinid flies, and other natural enemies.