Insect Perceptions, Irrelevant or Important

February 23, 2016

“IT WAS THE BUTTERFLIES, my people say, who brought the first human babies to their feet,” writes Canadian Richard Wagamese in “Butterflies Teachings,” an essay touching on “what’s called Enendamowin, or Ojibway worldview” in his brilliant collection, One Native Life. “Before that, the New Ones sat in innocence beneath a tree, watching the world around them with wonder. But Creator had planned more for them. Their destiny called for them to move throughout the world. These human babies were meant to walk upon their two legs, and as long as they sat under that tree their destiny could not be fulfilled…The air seemed to tremble with butterflies. The human babies were entranced. Each time they tried to snare a handful of colour, the cloud drifted away. They stretched their arms higher. They thrust out their hands. But it was to no avail. When the butterflies danced just out of reach a final time, the New Ones lurched to their feet and raced after them across the meadow. The Animal People celebrated quietly, then returned to their dens and burrows and nests. The human babies never caught those butterflies, but they kept on running, right into the face of their destiny…”

Quite a different worldview from Prague and Eastern Europe, where Franz Kafka’s famous novel Metamorphosis begins: “As Gregor Samsa awoke one morning from uneasy dreams he found himself transformed in his bed into a gigantic insect.” According to the “wall notes” in the exhibit “Disguise: Masks & Global African Art” at the Fowler Museum at UCLA, Kafka’s words inspired South Africa artist Walter Oltmann. Among neon masks, dancing mask videos and sculptured African animals wearing masks are Oltmann’s large anodized aluminum and brass wire caterpillars in the midst of “transformation and change” (metamorphosis) and fashion sketches titled “Beetles & Suits.” The suit coats are gracefully curving, shell-like beetle elytra (outer wing covers) fashionably topped off with the latest antennae, and looking both business-like and sci-fi out of Star Wars or Star Trek at the same time. I can easily imagine a cell phone age makeover of The Beatles’ Sgt. Pepper’s Lonely Hearts Club Band regalia and long hair with “beetle suits” and high-fashion antennae. Perhaps too much entomology affects the psyche. Oltmann writes that “spending an inordinate amount of time on making something that is usually considered insignificant like an insect, does make us look differently at them.” He says it “speaks of neither this nor that,” but I’m not so sure.

Insect observations appear in haiku by Japanese master Matsuo Basho, whom I think of as the late 1600s slightly more refined counterpart of 20th century Los Angeles poet Charles Bukowski, who was too busy with “other interests” to notice beetles, flies, mosquitoes and roadside weeds. In Moon Woke Me Up Nine Times: Selected Haiku of Basho, translator David Young writes: “Odd numbers predominate; a dance is occurring, and each third of the poem is a turn, a gesture, a refining or revelation… The poem seems to end almost as soon as it has begun, a small flash of lightning…A more literal version of the haiku cited (below) would be something like: What can save your life? / one leaf, with an insect / sleeping on its journey… the journey, which refers to a Chinese story that Basho’s readers would know but that is largely meaningless to English readers…‘Basho mash-ups,’ I have sometimes called my versions”:

One insect
asleep on a leaf
can save your life

Perhaps Basho was thinking of medicinal silkworms slumbering on mulberry leaves, or perhaps his mind was journeying among high mountains where ghost moths metamorphose with fungi into plant-animal hybrids that have been used in Asian medicine for centuries. David Young says about haiku: “They love to startle, first the writer and then the reader. As though a hummingbird were to land suddenly on your resting arm. It is the way the world so often surprises us.”

A haiku by Los Angeleno Mark Jun Poulos, whose observation of the seemingly mundane urban habitat nagged at me long after I thought I had dismissed its ordinary elements from consciousness:

restroom sink-—
ladybug cooling off
in a drop of water

What nagged at me was water, a vital ingredient of life, which as hard sprays of rain washes away pesky mites and aphids that are ladybug prey. Water (H2O) is also a missing ingredient in most ecological studies of interplanting, a habitat diversity strategy designed to boost populations of lady beetles and other beneficial insects providing natural pest control. Australian grape vineyards and California lettuce fields have had some success interplanting blooming rows of sweet alyssum to provide pollen, nectar and alternative prey for ladybugs, lacewings, hover flies and other beneficial species consuming aphids and other pests. Sweet alyssum is also host to micro-wasps helping Michigan asparagus growers by parasitizing leafmining pest insects, Amanda Buchanan of Michigan State University reported at the Entomological Society of America (ESA) annual meeting in Minneapolis. But if habitats are missing water, then perhaps lady beetles, which do not puncture plants to drink fluid, will leave to find restroom sinks, puddles or other water sources. Perhaps, like providing water bowls for pets, something similar needs to be researched as part of biological control habitat alternatives. Though I would draw the line at alcoholic drinks, except perhaps beer in snail and slug traps. Another urban haiku observation by Mark Jun Poulos:

sultry afternoon—
wasp hovers over a whiskey bottle
held by a drunk bum

Ethanol or ethyl alcohol, by percentage the main chemical component of distilled whiskey, should not be abused, nor perhaps should it be so heavily subsidized as a biofuel, as that incentive exacerbates huge landscape changes measurable as reduced biodiversity. At Synergies in Science, a rare Minneapolis gathering of the ESA, American Society of Agronomy, Crop Science Society of America and Soil Science Society of America, the diminishing biodiversity of a Midwest USA with 21% less wheat, 16% less hay and much more GMO corn to distill into ethanol motor fuels was as hard to ignore as a drunk with a whiskey bottle on an urban bench. Jonathan Lundgren of the USDA-ARS in Brookings, South Dakota said we need to get away from our “very pest-centric approach” and adopt a more holistic biological network approach. Instead of a Midwest saturated with pesticides to grow GMO corn to distill into fuel tank ethanol, something as seemingly simple as adding biodiversity via cover crops amongst the corn rows could produce enough soil biocontrol of corn rootworm to eliminate wasteful neonicotinoid seed treatments whose honey bee and beneficial insect friendliness is being hotly debated. Karen Friley of Kentucky State University reported at the ESA that something as seemingly simple as native plant border rows around sweet corn fields “provide microclimates in the form of moderated temperatures, which offer shelter” for numerous natural enemies controlling corn pests.

Curiously enough, ethanol (alcohol) like that in whiskey bottles and vehicle fuels also attracts pine beetles and ambrosia beetles considered destructive forest, landscape, street tree and nursery pests. Perhaps more curiously, the very trees being attacked are producing the ethanol and releasing it into the atmosphere when stressed (e.g. by drought or flood), decaying or dying. Trees may look perfectly healthy on the outside, but inside the tree is another story, because ethanol emissions are signs of sickliness and ill health. Chemical ecologist Christopher Ranger of the USDA-ARS in Wooster, Ohio said it is a real problem, for example, when nursery seedlings are used to replant spruce forests or with dogwoods, magnolias, pines, etc. in nurseries, backyards, along streets, etc. It is definitely ecology, as the ethanol is luring in the beetles to help “recycle” the trees back into the soil as nutrients.

I liked Ranger’s reasoning: Find the tree equivalent of driver breathalyzer tests as a beetle-attack early warning system. SCRAM wrist bracelets worn by offenders for transdermal drug and alcohol detection were tested, but were not sensitive enough; taking a week to detect low tree ethanol exhalations, whereas beetles detect a few parts per million of alcohol and get to trees almost on day one. The solution was a portable ethanol monitoring device with a detector tube and a plunger to pull in air samples; developed using Japan’s Gas Tech industrial gas leak detection technology for quick detection of “inebriated” trees.

So, which is more startling and surprising: art, haiku or entomology?

Strange brew: September 17, 2015 daylight turning to dark, caught in one of those infamous, almost proverbial L.A. traffic jams at a freeway underpass on Church Lane transitioning from Sunset Blvd to Sepulveda Pass on my way past the Getty Museum to Mulholland Drive, listening to the Moody Blues Live at Red Rocks, going nowhere. Haiku and fireflies flashing internally, and externally the blinking side turn lites and red back brake lights suddenly and surprisingly metmorphosed into synchronous fireflies, albeit of a mechanical or robotic nature:

Tail and Turn Lights
Flashing like Synchronous Fireflies
In the Los Angeles Traffic Jam

 

Advertisements

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.


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.


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.