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.

Native Bees Pick Up Pollination Slack (Combating Colony Collapse)

May 3, 2012

HONEY BEE COLONY COLLAPSE Disorder (CCD) is a murky headline catch phrase, a scientific-sounding term that is almost a euphemism, to describe a population decline. In other words, there are fewer honey bees than there used to be, which is bad for agricultural crops dependent upon these domesticated insects for pollination.

Why a population decline is called a “disorder” is a bit beyond me, though it sounds almost clinical or medical. Perhaps that is the point; and calling it a disorder makes it a more respectable object of study and aids in obtaining funding and public support for research and finding a remedy. The declining human populations in Russia, Italy, Germany, Japan and other developed countries are not called a disorder; which perhaps implies an underlying value judgment. Might be nice to discover a Bed Bug Colony Collapse Disorder (BBCCD) to give cause for celebration. Though the acronym BBCCD in the Google search engine would confusingly yield CDs from the British Broadcasting Corporation (BBC).

Wikipedia makes it sounds like honey bees are being kidnapped: “Colony collapse disorder (CCD) is a phenomenon in which worker bees from a beehive or European honey bee colony abruptly disappear. While such disappearances have occurred throughout the history of apiculture, the term colony collapse disorder was first applied to a drastic rise in the number of disappearances of Western honey bee colonies in North America in late 2006…” If such occurrences have been happening throughout history, then the “disorder” sounds more like normality. In any case, times are tougher for those relying upon domesticated honey bees for crop pollination.

The interesting flip side of honey bee colony collapse disorder is the almost metaphorical return of the natives: Really a rediscovery and new appreciation of overlooked native pollinators like North American squash bees, digger bees, miner bees, sweat bees, bumble bees, and syrphid flies.

Whether you call it a disorder or a population decline: Nature abhors a vacuum or an empty ecological niche, like an absence or paucity of pollinating honey bees in a flowering agricultural ecosystem. Niches tend to get filled in nature, though the process may take years. With fewer honey bees (Apis mellifera is an introduced species in the Americas) in the fields, native bees hitherto ignored or overlooked are taking over the pollination chores on certain crops, according to research presented at Entomological Society of America (ESA) meetings.

“Nearly 4,000 species of native bees are found in North America,” said the University of Kentucky’s Amanda Skidmore. Integrated Pollination Management (IPM) or Integrated Crop Pollination, jargon phrases that sometimes popup at meetings, refers to managing crop ecosystems as habitats for native pollinators.

“In order to best utilize bees as pollination service providers, agro-ecosystems must be managed to attract and sustain them based on their natural history biological requirements,” Skidmore told the ESA. These habitat requirements include “energy (nectar), larval food proteins (pollen), and protected nesting sites (i.e. untilled earth, nesting boxes, dead plant matter).”

Native long-horned bees (Melissodes bimaculata) take up some of the slack from depleted honey bee populations in Kentucky by pollinating squash, melon and vegetable crops. Sweet alyssum (white-flowered variety), a flower interplanted in agricultural crops to promote biological control of pests by natural enemies, was heavily favored by the native pollinators; along with bee balm (Monarda didyma) and wood sage (Teucrium canadense). The idea is to plant a succession of flowering resources, including native wildflowers, shrubs and trees, to sustain native pollinators from very early season to late season. Research on habitat plantings is on-going.

Native North American sweat bees (Halictidae) and digger or mining bees (Andrenidae) are abundant pollinators of Michigan’s important blueberry crop in some locales, Michigan State University researcher Rufus Isaacs told the ESA. Nearby meadows “grow” sweat bee populations that move into blueberries to provide pollination services. Well-drained soils mean more nesting habitat for digger or mining bees that also pollinate blueberries. Several dozen wild native annual and perennial plants with varied bloom periods are being test-grown near Michigan blueberries to determine which best boost native bee populations and reduce the need for honey bee pollination.

Similar strategies for adding habitat for native pollinators are also being researched in crops as diverse as apples, cherries, squash and watermelons in regions as far-flung as Florida and California.

Earthworm Compost, Medicinal Honey & Fewer Hive Sprays Avert Bee Collapse

April 4, 2012

HONEY BEE COLONY COLLAPSE DISORDER and subtle learning and memory pesticide effects were among Biocontrol Beat topics detailed in Feb. 2011 (Honey Bees, 24-Hour Surveillance Cameras & Pesticides). For many attendees of Entomological Society of America (ESA) annual meetings, the two reports on pesticide effects on honey bees and bumble bees in the 30 March 2012 issue of Science magazine were just two more data bits, nothing particularly surprising; albeit good headline news fodder and a bit troubling. Perhaps a slight feeling of déjà vu for those familiar with Rachel Carson and her book of more than half a century ago, Silent Spring.

To imbibers of energy-boosting, nervous system stimulants like coffee, tea, and the many other caffeinated beverages flooding the marketplace, the idea that a common natural (e.g. botanical) or synthetic chemical might affect behavior is almost a no-brainer, though not necessarily self-evident. Caffeine has gone from fruit fly studies to mosquito control remedy recently. Natural nicotine from tobacco family plants has had almost an opposite trajectory, having once been widely used (e.g. burned as a fumigant) and recommended (e.g. soaking cigarette butts in water) for pest control in agriculture, greenhouses, and organic gardens; and now shunned because of its toxicity to humans and beneficial insects.

Neonicotinoid pesticides, like the widely used imidacloprid, had their design inspiration in natural nicotine molecules; but are safer to humans and other animals. But perhaps not totally without adverse effects, if indeed it is possible to have a substance that is toxic and yet totally safe. The Science reports associate neonicotinoid chemicals like imidacloprid with reduced bumble bee colony size and queen production, as well as lower honey bee survival and foraging success.

Though the scientific data will be subjected to further debate and future studies may confirm or refute the results, Science magazine writer Erik Stokstad, in an accompanying news and analysis, marshaled a stunning statistic to go with the reports: “In the United States alone, 59 million hectares of crops are protected by systemic pesticides. Seeds are treated with these neurotoxins before planting, and the poison suffuses the tissues, pollen, and nectar…”

Nonetheless, as ESA annual meeting habitués may know: genetics, pathogens, parasites, and beekeeper practices apparently also figure into the still mysterious honey bee Colony Collapse Disorder (CCD). Perhaps aptly for a confusingly mysterious disorder, CCD, the acronym for Colony Collapse Disorder, is confusingly the same as the Community College of Denver, charged-coupled devices (like those capturing images in digital cameras), Confraternity of Christian Doctrine, and The Convention Centre Dublin, to mention but a few highly-ranked “CCD” terms in Google.

Those who put their faith in scientific panels, better testing, and more government regulation will be heartened to know that Stokstad says more is on the way in Europe and the USA. Those wanting to do something practical right now to help the honey bees and native bumble bees pollinating their backyards and fields might find more encouragement in some of the presentations coming out of the Entomological Society of America (ESA) annual meetings.

For example, North Carolina State University soil ecologist Yasmin Cardoza, who has shown that earthworm compost produces plants more resistant to caterpillar pests and aphids, more recently told the ESA that amending a cucumber soil (model system) with earthworm compost (vermicompost) helped bumble bees and other native pollinators become heavier, healthier, and more fecund.

Cucumber plants grown in soils amended with earthworm compost had flowers (pollen, nectar) with significantly more protein and a bit more sugar. These more nutritious flowers grown with earthworm compost attracted more bumble bees and native pollinators. Plus the bumble bees had more and larger ovary cells and egg tubes (i.e. an indication of enhanced reproduction), weighed more, and had fewer disease pathogens. Whether earthworm compost can reverse or prevent Colony Collapse or create Colony Expansion would make for an interesting study.

Beekeeping methods also take a hit for exacerbating honey bee problems; and are illustrative of how mites, insect pests and pesticides make for the type of challenging problem that in previous centuries were solved by privately-funded freelance scientists like Louis Pasteur. Pasteur’s freelance entomological endeavors included almost single-handedly rescuing the nineteenth-century silk industry from a similar mysterious collapse of silkworm colonies (insect colonies seem particularly prone to epidemic collapse when you want them; but resistant to collapse when you would rather be rid of them, like termite and fire ant pests). Rene Dubos’ account in his 1950 book, Louis Pasteur Free Lance Of Science, is well worth reading for free on the Internet (pdf, Kindle versions). By early twenty-first century standards, Pasteur seems almost like a Rambo of science, accomplishing with a few assistants what would seem impossible today.

Even if the cause of honey bee colony collapse is still mysterious, like silkworm colony collapse was prior to Pasteur, there is no doubting the reality of the problem.

“In Virginia, the number of managed honey bee colonies have declined by about 50% since the late 1980s due to the introduction of parasitic mites,” Virginia Techie (Blacksburg, VA) Jennifer Williams told the ESA. “Excessive reliance” on fluvalinate (a pyrethroid miticide) and coumaphos (an organophosphate miticide) have “been implicated in numerous problems to honey bees, including impaired reproductive physiology, reduced ability of colonies to raise queens, reduced sperm viability in drones (males), and increased queen failure and loss.” Often these miticides are found in combination with imidacloprid (systemic insecticide), chlorothalonil (broad-spectrum fungicide), and the broad-spectrum antibiotics oxytetracyline and streptomycin used by beekeepers to combat American foulbrood disease in honey bee hives.

Fluvalinate, coumaphos, coumaphos-oxon, and chlorothalonil are found in almost half of North American honey bee colonies at ppb (parts per billion) levels that can be acutely toxic. Combining miticides, pesticides, and antibiotics is a toxic cocktail recipe boosting honey bee mortality 27-50%, according to Williams. In other words, it is a vicious circle in which beekeeping practices (e.g. miticides, antibiotics, substituting sugar water for honey) may have deleterious effects offsetting curative effects on already weakened and mentally confused bees feeding on plants treated with pesticides rather than healthy composts like those being studied by Cardoza.

As if honey bees did not have enough health problems, the small hive beetle (Aethina tumida) is now part of the mix. “In their native range in South Africa, these beetles cause relatively little damage,” Natasha Wright of the University of Arkansas told the ESA. “However, they can be destructive to honey bee colonies in the United States and Australia. The adults and larvae feed on bee brood and bee products. They also cause honey to ferment, which results in unsellable honey. Little is known about the biological control agents.”

“Identifying new mechanisms that support honey bee health will be pivotal to the long-term security and productivity of American agriculture,” Emory University’s Lydia McCormick told the ESA. “Hydrogen peroxide is a potential natural defense/stress response to small hive beetle,” a pest which can devastate a honey bee colony in weeks or months. Not to knock beekeepers, who have enough problems already, but their practice of feeding bees sugar water rather than honey laced with hydrogen peroxide may be part of the problem. Honey bees produce more hydrogen peroxide in their honey to combat stressors like the hive beetle.

“Extremely low concentrations of hydrogen peroxide in sugar-water fed samples may represent a problem in this common method of hive management,” said McCormick. “Honey bees may selectively regulate higher brood honey hydrogen peroxide as a strategic oxidant defense. Given that brood cells contain honey bee larvae, high honey hydrogen peroxide may help protect against pests.” Indeed, small hive beetle survival is lower with hydrogen peroxide in the honey.

Honey containing hydrogen peroxide has been marketed for its antibacterial, wound healing, and skin care potential; and prescriptions for medical-grade honey are a possibility. New Zealand professor Peter Charles Molan published an interesting historical review on honey for wound healing in 2001. Besides hydrogen peroxide, honey may have healing botanical compounds (phytochemicals). Perhaps the bee’s loss is humankind’s medical gain. Though if the bees are lost as pollinators in the process, it is not a sustainable practice in the longer-term.

Liquid Nitrogen Sprays Freeze Bed Bugs in Italy

February 24, 2012

THE WORLDWIDE BED BUG infestation, with all its miseries and desperation, has given rise to innovations from common molecules like cold liquid nitrogen gas (N2). Being 78% of planet Earth’s atmosphere and the air we breathe, liquid nitrogen gas is considered by some an ecological bed bug remedy. As John Emsley points out in his book, Nature’s Building Blocks, a copy of which I stumbled upon in Century Books near Pasadena’s Caltech: A bit over 78% N2 gas and the atmosphere goes from breathable to death by asphyxiation. Not that you would breathe better on Mars with its 2.6% nitrogen atmosphere; though neither would bed bugs survive, if leaving the planet to escape the plague were an option.

In its freezing cold liquid form, nitrogen gas freezes bed bugs and most everything else. Besides freezing and preserving genetic materials, liquid nitrogen is used in dermatology to freeze and excise warts, small lesions, early-stage skin cancers, and actinic keratosis. Liquid nitrogen treatments are called cryotherapy or cryosurgery, not because it makes you want to cry out in pain. But rather because cryogenics (physics) is the study of low temperatures. According to the National Cancer Institute, the extreme cold of liquid nitrogen is even used inside the body to freeze and excise cancerous pancreatic and liver cells, childhood retinoblastoma, precancerous cervix disorders (cervical intraepithelial neoplasia) and noncancerous bone tumors.

Italy, which has 400 pest control operators (PCOs) specializing in bed bugs, is the meeting ground for liquid nitrogen and bed bugs, reported Riccardo Biancolini and Guglielmo Pampiglione of the Istituto G. Caporale (Teramo, Italy) at the Entomological Society of America (ESA) annual meeting in Reno, Nevada. As people travel from north to south on trains and buses and stay at hotels or hospitals, Italy’s 21 regions and 50 million people have been exposed to the modern day bed bug resurgence.

The liquid nitrogen spray method developed by Ecotrade(R) (Roma, Italy) is called the Criopest method. Ecotrade’s Criopest method sprays liquid nitrogen at -196 C (-320 F) to freeze bed bugs and other pests. Liquid nitrogen has percolation effects, penetrating pillows and carpets to kill bed bugs. Italian hotels hire specialist PCOs who guarantee 100% results, and like the fact that after 1-2 liquid nitrogen treatments hotel rooms can be immediately rented again. The cost in 2011 was $400-600 euros per room. Well worth it if you are in the room rental business; and less costly than conventional bed bug treatments. The Italians told the ESA that 80% of their clients choose the Criopest liquid nitrogen option.

Liquid nitrogen is usually combined with other methods, as bed bugs are a tough pest to ferret out. As part of IPM (Integrated Pest Management) programs, the cold liquid nitrogen treatment of carpets and bedding might be combined with heat (hot dry air) to kill bed bugs on textiles. Also items to be disinfested are placed in bags with pyrethrin gels for 210 minutes. As part of the multi-modality IPM approach, pesticide treatments (only about 75% effective in 5 days) are also used to leave behind chemical residues in places like electrical sockets where bed bugs, cockroaches, and other pests might hide.

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.

Compost for Sustainable Soil Fertility & Disease Suppression

July 24, 2010

ABOUT A THIRD of farm energy used for food growing supplies fertility. In Florida alone, the energy used to manufacture the 2 million tons of food crop fertilizer each year equals the energy content of 100 million gallons of diesel fuel. Thus, recycling or composting waste materials into fertilizers and mulches can save energy while reducing pollution and enhancing human and crop health.

In the book Farmers of Forty Centuries; Or, Permanent Agriculture in China, Korea and Japan, early-1900s agricultural scientist Franklin Hiram King observed amazing levels of soil productivity where rural and urban human wastes were recycled back to the land and farmers planted legume (e.g. soybean; adzuki bean; clover) and other green manure cover crops and crop rotations.

“Japanese society once faced the prospect of collapse due to environmental degradation, and the fact that it did not is what makes it such an instructive example,” writes Azby Brown in his 2010 book, Just Enough: Lessons in Living Green from Traditional Japan. “Japan entered the Edo period in 1603 facing extreme difficulties in obtaining building timber, suffering erosion and watershed damage due to having clear-cut so many of its mountains for lumber, and virtually unable to expand agricultural production…All the more remarkable, then, that 200 years later the same land was supporting 30 million people-2.5 times the population…Deforestation had been halted and reversed, farmland improved and made more productive, conservation implemented…Overall living standards had increased, and the people were better fed, housed, and clothed, and they were healthier. By any objective standard, it was a remarkable feat, arguably unequalled anywhere else, before or since.”

Human waste, euphemistically called night soil, became a valuable soil fertility commodity in old Japan. Perhaps not quite worth its weight in gold, but a valuable commodity bought, sold, traded, and transported long distances from cities to farms. Rather than causing cholera and other diseases by entering the water supply as was common in European cities of the same era, sanitation and composting blessed Japan with multiple dividends. Considerable energy was “expended on toilet design to allow these waste products to be easily collected and processed,” writes Brown. This has culminated in modern dry composting toilets that “by allowing natural composting heat to occur inside a well-ventilated compartment…turn human waste into a dry, nearly odorless compound that looks and feels like peat moss.”

Farmers in old Japan spent their own money to “build toilets and urinals along well-traveled roads for public use, in the hopes of increasing their yields of fertilizer.” Contrast this with the modern difficulty of finding a decent, well-maintained public toilet along roadsides or in cities. China, says Brown, “is poised to become the global leader in composting toilets, partly because relatively few communities are served by the sewer infrastructure and the government is promoting these new designs as an attractive alternative that will help mitigate its freshwater problems as well.”

In the modern Western world, scientists in Germany and the USA have advanced the conversion of animal manures and green plant wastes into composts and tea sprays that boost plant growth and suppress pests. Though long a staple of biodynamics and organic gardening, in the 1980s University of Bonn researchers like Heinrich Weltzien, Andreas Trankner and Ketterer provided experimental proof that watery compost tea sprays high in beneficial microbes reduced powdery mildew on grapes and late blight disease on potatoes. Indeed, in some experiments compost tea sprays formulated from grape marc, earthworm compost, and animal manures equalled synthetic fungicides.

In the USA, in 1969 reports surfaced that some Ohio nursery growers had conquered root rot diseases in rhododendrons, cyclamens, and other ornamentals using pine bark composts and no longer needed methyl bromide soil fumigations. Ohio State University’s Harry Hoitink embarked on scientific studies of this phenomena. To reliably control the plant pathogens causing root rots and other soil diseases, hardwood bark composts were aged like fine wines for 6-12 months or fortified with special biocontrol microbes. In Australia, eucalyptus bark is similarly composted to combat Pythium and Phytophthora root rot pathogens in container or potted plant soils and avocado orchards.

Insect pests can also be controlled with composts. For example, Cornell entomologists like Michael Villani and Roxanne Broadway stopped white grub beetle larvae from attacking turf and lawns using crude proteins extracted from composted leaves and kitchen food wastes. Composted chicken manure and feathers worked best against caterpillars (moth larvae). Cornell University’s Eric Nelson and others have spent years formulating composts to combat root rots on golf greens and maladies like dollar spot and brown patch.

It may take a year or two of aging to brew the right combination of pest-suppressive beneficial microbes in composts. In Japan, composted golf course grass clippings are specially inoculated with a strain of the beneficial bacteria Bacillus subtilis to hasten suppression of the fungus Rhizoctonia solani on golf courses.

However, compost is not always a quick cure. For example, several years of compost applications are needed to control soybean cyst nematodes in agricultural fields or to restore Japanese forest soils. That is because plant ecosystems are complex adapative systems.

Ozone Oxygen (O3) Fumigation for Organics

June 29, 2010

OZONE, A NATURAL OXYGEN (O3; 3 oxygen atoms) molecule that can also be synthesized, is among many other things an alternative to fumigants such as chlorine, methyl bromide, phosphine, and sulfuryl fluoride. Modern day humans have an almost schizophrenic, Jekyll-and-Hyde relationship with ozone, alternately and simultaneously seeking to eliminate and preserve ozone in the environment.

At stratospheric heights 12-15 miles (20-25 km) above the Earth’s surface, in what is called the ozone layer, 90% of the planetary ozone swirls and drifts about in molecular clouds, protectively absorbing mutation-inducing ultraviolet solar radiation wavelengths (also linked to immune disorders, cataracts, skin cancer, crop damage). For that reason an international treaty, the Montreal Protocol, was enacted in the mid-1980s to protect the ozone layer against known and unknown (to be discovered in the future) molecules destructive to ozone. That’s the good Dr Jekyll aspect of ozone (with apologies to Strange Case of Dr Jekyll and Mr Hyde author Robert Louis Stevenson).

Closer to Earth’s surface, where the 10% of planetary ozone not in the upper atmosphere resides, metropolitan areas such as Los Angeles and Phoenix suffer from ozone pollution and come under regulatory fire from the U.S. Environmental Protection Agency (EPA) because what is good 12 miles high is harmful at ground level. In “America’s Most Polluted Cities,”’s (04.28.10) Tim Kiladze calls it “harmful ozone, a ground level gas that contributes to urban smog and inflames the lungs, causing shortness of breath, wheezing and throat irritation.” The American Lung Association State of the Air 2010 report web site formulates EPA ozone and particle pollution data for American cities and counties into searchable form.

So, will ozone gas as an alternative to ozone-destroying fumigants like methyl bromide create more ground level ozone pollution or help replenish and preserve the protective stratospheric ozone layer?

“Chemicals can have their seasons, just like fashions. What one age admires as fine, another will reject as folly, and a good example of this is ozone,” writes John Emsley in his 1998 book, Molecules at an Exhibition. “A century ago ozone was also something to worry about, and for exactly the opposite reason: it was thought there was not enough of it around. Ozone was deemed to be natural, wholesome and invigorating, and the very locations where its levels were highest proved this: up in the mountains and along the coasts…Such was the esteem in which the Victorians held ozone that they had generators pumping it into churches, hospitals, theatres and even their underground railways.”

At the 2009 Entomological Society of America (ESA) annual meeting in Indianapolis, ground-level ozone was back in fashion as an environmentally-friendly fumigant molecule (unstable; decomposes quickly). Methyl bromide (another natural molecule) faces demise as a fumigant under the Montreal Protocol for destroying ozone. And stored grain insect pests are becoming resistant to phosphine. Carbon dioxide, a waste gas exhaled by humans and a feedstock of sorts for green plants, has some fumigant potential but is too slow-acting and unfashionable as a warming greenhouse gas.

Though it is easy to pump ozone through hoses into grain bins, ozone does not penetrate the dense grain well and fumigations can last 3-10 days. Purdue University’s Marissa McDonough noted that the grain is more quickly disinfested of red flour beetles (Tribolium castaneum), maize weevils (Sitophilus zeamais) and other pests by physically moving the grain in layers exposed to ozone sprays in passing.

Potency, ease of use, and low cost make for a good fumigant, said Kansas State University’s Mahbub Hasan, who noted that phosphine, sulfuryl fluoride and ozone are all potential alternatives to methyl bromide fumigation for dry-cured hams attacked by red-legged ham beetles (Necrobia rufipes), ham mites (Tyrophagus putrescentiae), cheese skipper flies (Piophila casei) and carpet beetles (Dermestidae). Carbon dioxide was too slow, said Hasan, taking six days to knock out ham mites. An integrated (IPM) approach combining biological controls, cooling, pheromone traps, ozone and botanical fumigants may ultimately be devised for protecting stored foodstuffs.

However, ozone remains out-of-favor in the plant world. “Tomato plants may be more susceptible to wounding by caterpillar pests in ozone than in ambient air,” Western Illinois University’s Sue Hum-Musser told the ESA meeting in Indianapolis. “Several genes play important roles in plant defenses against the combined stress of ozone and insect herbivory. Increasing ozone levels cause damaging effects on the plant community, and insect pests cost billions of dollars to agriculture.”

Fashion is a fickle thing, and future ozone fashions will likely remain a twenty-first century Jekyll and Hyde muddle.

Honey, Bees, Better Sleep & Memories

April 24, 2010

“A TEASPOON OR TWO of honey before bed insures a restorative sleep,” writes Reese Halter in his informative little book, The Incomparable Honeybee & The Economics of Pollination. “A human liver stores about eight hours of glycogen – an important brain food. If you eat supper at 7 pm, by about 3 am your brain releases a stress hormone called cortisol. Cortisol scavenges the body, melts muscle tissue and converts it into glycogen to feed the brain. When released, cortisol causes the heart to beat faster and raises glucose insulin levels in the blood. Elevated cortisol can lead to obesity, diabetes, coronary disease and autoimmune breakdown. A teaspoon of honey at night fuels the liver with glucose and fructose, which is absorbed slowly – thus providing a restful sleep and preventing the release of cortisol.”

Perhaps honey also helps bees with their sleep?

In the 27 March 2010 Philosophical Transactions B of the Royal Society, researchers Timothy C. Roth and Vladimir V. Pravosudov at the University of Nevada, Reno, and Niels C. Rattenborg at the Max Planck Institute in Germany “examine the ecological relevance of sleep” for “memory/learning and hypothermia/torpor to conserve energy.” Sleep, it seems, is still a somewhat mysterious function. However, sleep in honeybees and other animals lends itself to ecological and experimental study.

Honeybee sleep is not exactly the hottest research topic on the planet at the moment. But that may change as the links between honeybee sleep, pathogen spread, and diseases are further explored. At past Entomological Society of America (ESA) meetings, Barrett Klein, who is finishing his Ph.D. in Ecology, Evolution and Behavior at the University of Texas in Austin, has attracted more attention for his entertaining role in insect art symposia.

At the Biozentrum in Wurzburg, Germany, Klein used an infrared camera to measure temperature changes and map sleep patterns of Carniolan bees (Apis melifera carnica) as they aged and changed tasks over time. Young worker bees progress from cleaning hive cells to nursing to food storage to foraging as they age.

Older forager bees sleep mostly at night, outside of cells, close to the edge of the hive where it is coldest. Younger cell cleaning bees sleep day and night, mostly inside cells where it is warmest. Foraging honeybees are the caste most likely to bring pathogens back to the hive. Thus, sleeping at night in the cold near the edge of the hive away from the warm brood reduces the potential for pathogen spread to the rest of the hive.

In the journal Learning & Memory, researchers in Germany used a web camera to “address the question if sleep in bees, like in other animals, improves memory consolidation.” Indeed, the webcam revealed that sleep deprivation had some negative effects on honeybee memory. At the ESA, Edgar Hernandez of the University of Missouri in St Louis described some of the work with “clock genes” and “clock proteins” playing a role in determining when bumble bees sleep.

With honeybees in trouble due to colony collapse, bumble bees and native bees are getting more attention. Nancy Adamson of Virginia Tech reported to the ESA that the honeybee situation has become so worrisome that the Virginia State Legislature voted to support research “aiming to provide information to Virginia farmers interested in supporting a broad spectrum of pollinators on their crops.” This includes providing harborage and habitat for bumble bees and other native bees.

“North America boasts over 4,000 species of native bees, many of which could serve as crop pollinators,” said Ann Fraser of Michigan’s Kalamazoo College. Native bees and bumble bees can pollinate crops on cloudy days and in cooler weather when honeybees are less active. Indeed, New Jersey and Pennsylvania watermelons are pollinated by 46 native bee species. In New York pumpkin fields, more bumble bee visits means heavier pumpkins, said Cornell’s Derek Artz.

Native bees and bumble bees can also be part of urban renewal. According to Ohio State University’s Scott Prajzner, vacant land within the city centers of Akron and Cleveland now supports community gardens and urban farms. This has boosted populations of native squash bees (Peponapis sp) and long-horned bees (Melissodes sp).

Perhaps we will all sleep better and have a more sustainable food supply by getting back to the basics: Honeybees for honey production, and letting bumble bees and native bees handle more crop pollination.

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.

Wintergreen = Biocontrol Aromatherapy

September 18, 2009

WHEN ENTOMOLOGISTS hip to chemical ecology speak of HIPPOs, they mean HERBIVORE INDUCED PLANT PROTECTION ODORS, not the massive hippopotamus native to riverine Africa. At Washington State University (WSU), David James and his entomological colleagues have spent the last several years testing fragrant wintergreen oil, a common HIPPO produced by distressed plants, as a means to boost biological control of crop pests by natural enemies.

The same fragrant wintergreen oil (high in methyl salicylate) used in mints and mouthwashes can be formulated into slow-release dispensers to attract beneficial insects into crops in greater numbers earlier in the season than would otherwise be the case. The dispensers minimize environmental and worker health impacts and crop damage (phytotoxicity). Also, the dispensers can last 3-4 months, providing extended periods of natural enemy attraction. Sprays evaporate more quickly, potentially meaning more applications. Nevertheless, spray technologies are still very popular and 2% wintergreen oil in canola oil is being test sprayed worldwide in crops ranging from hops and cotton to soybeans, strawberries and sweet corn.

In their earliest hop yard and grape vineyard field tests, James and his coworkers found that wintergreen oil attracted significantly higher numbers of pest natural enemies like predatory green lacewings, minute pirate bugs (Orius spp.), spider mite-eating lady beetles (Stethorus spp.), and aphid-eating syrphid flies. By getting higher numbers of natural enemies into the fields earlier than might otherwise have been the case, pests like spider mites were kept under biological control all season long. Leafhopper numbers were also lower, leading James to suspect that parasitic wasp species attacking this pest were also boosted by wintergreen oil.

This is the basis for commercial products such as PredaLure, sold by Rincon-Vitova Insectaries and others to maximize natural enemies providing biological pest control. Plants are virtual chatterboxes of chemical communication, and wintergreen oil and methyl salicylate are just the tip of the iceberg in terms of natural compounds awaiting field testing. Farnesene, caryophyllene and the male-produced lacewing aggregation pheromone iridodial are among the other green lacewing attractants attracting research attention.

When attacked by insects, spider mites, and pathogens (e.g. viruses, bacteria, fungi) or under environmental stress (e.g. chilling, drought, salinity), plants can ooze chemical exudates from their roots into the soil and waft a variety of communication chemicals into the wind. Thereby neutralizing pathogenic soil microbes, luring in pest-eating natural enemies and tipping off downwind neighbors in the plant community to ramp up their immune response in preparation for impending pest attacks.

We have only scratched the surface of what exists and what is possible to develop for biological insect control.