Nature of Conservation

Judith Rutschman interviewed me on a segment of her TV program, Nature of Conservation. The recent interview was my second filming of the program. Our first interview in 2008 discussed Peace Bee Farm’s activities, mostly producing honey and beeswax products. At that time, a mysterious condition in which the adult worker bees disappeared from their hives was in its second year. We discussed the researchers’ efforts being undertaken to identify the causes of the resulting massive honey bee die-off, called Colony Collapse Disorder, or CCD.

With the passing of seven years, Judith and I revisited Peace Bee Farm’s operations and the condition of honey bees across America and around the world. The continuing die-off of bees brought about ample media coverage, resulting in considerable public interest. Media attention helped bring about a number of university studies seeking the cause of CCD. Peace Bee Farm participated in several of these studies. Many concerned individuals responded by purchasing bees and hives. These new beekeepers eagerly sought beekeeping training and guidance. My role shifted over the next years to more involvement in beekeeping training and mentoring. After a few years of training beekeepers in the Mid-South, I was given the opportunity to travel to Africa to train beekeepers in Ethiopia. In some of my African assignments, I taught experienced beekeepers how to transition from traditional hives placed high in tree tops to modern bee hives. Sometimes I trained seasoned African beekeepers in new skills to share with others when they returned to their local villages. At other times I gave farmers their first lessons in beekeeping. These men and women built Kenyan Top Bar Hives at no cost using materials that they gathered locally: wood scraps, sticks, mud, and cow dung. It was always heartwarming to know that the products of the bee hives, honey and beeswax, helped increase the farmers’ incomes and ultimate survivability. Today’s photo: Judith Rutschman and Richard Underhill. See Nature of Conservation on WYPL, Memphis Channel 24, in December.

--Richard

Global Warming and Bumblebees

When Colony Collapse Disorder was detected in 2007, researchers immediately started searching for causes of the massive honey bee die-offs. They also looked at other species of bees to see if they were being affected as well, and they found that several species of bumblebees are also declining. We now know that honey bee and native bee populations are declining as a result of a combination of factors including habitat loss, nutritional problems, pesticides in the environment, and increasingly virulent pathogens. A large-scale study of bumblebees in Europe and North America concludes the effects of global warming as also being significant contributors to bee losses. The study described in The New York Times, http://www.nytimes.com/2015/07/10/science/bumblebees-global-warming-shrinking-habitats.html, traces 420,000 observations of 67 species of bumblebees over 110 years. The researchers analyzed bumblebee observations for every year from 1900 through 2010, recording the geographic range of each species. They found that bumblebee ranges declined at “continental scales” in the years following 1974 when human-caused climate change increased at a significant rate. With temperatures rising by two degrees Celsius since 1974, the southern limits of bumblebee ranges retreated toward the north at a rate of about three miles per year. One species of bumblebee once found in North Carolina and the Mid-Atlantic is now found in Maine, New Hampshire, Ontario, and Quebec. Another bumblebee once found in Georgia is now found in small numbers in Illinois, Maine, and Wisconsin. The researchers were surprised to find that bumblebee ranges didn’t merely move northward; the areas shrunk. The northern borders of the bumblebees’ ranges didn’t move into new territories.

As climate changes occur in temperate regions, like Europe and North America, species relationships are changed. Timings of flower blooming may result in a dearth of food for bees at critical times. Some species can’t tolerate changes in climate heat. In today’s photo, we see bumblebees foraging pickerelweed flowers along an Arkansas waterway. The native pickerelweed is an efficient biological filter of polluted water.

--Richard

Integrated Stress Management

When Colony Collapse Disorder was first detected in the U.S. in 2007, many factors were investigated as possible causes. No single cause arose, but colony stress was found to be a common denominator in all losses. Stress appears to come from three broad areas: increasingly virulent honey bee pathogens, neonicotinoid insecticides, and nutritional issues. The combined effect of these stressors weakens the bees’ immune system and leads to colony collapse. Honey bee pathogens are spread by parasitic Varroa mites. Tracheal mites still afflict bees, along with Nosema disease and Small Hive Beetles. Neonicotinoid insecticides are in wide-spread use throughout agriculture and lawns. Nutritional problems for bees often result from monocultural crop plantings and the loss of weedy flowering plants after the conversion of natural areas for industrial agriculture, pavement, and lawns

European researchers, writing in the journal Trends in Parasitology, http://www.eurekalert.org/pub_releases/2014-11/cp-csm111814.php, call for beekeepers to employ new schemes of “Integrated Stress Management” to help combat the effects of external stresses on bee immune systems. The researchers explain that honey bees “evolved unique mechanisms for interacting with pathogens.” Reducing stress may help the resilient bees survive. Often, this simply means examining our beekeeping practices. As we plan an integrated stress management plan, we may consider: Ensure that winter hives are dry and well ventilated. Every hive should have adequate stores of food—both honey and pollen—throughout the year. Don’t excessively rob the hives of their honey stores expecting to replace honey with sugar syrup or high fructose corn syrup, sources of carbohydrate lacking honey’s other nutrients. Don’t excessively split hives or shake bees to produce packages. Small colony size leads to problems like diminished foraging capacity, difficulty regulating hive temperature, either warming the winter cluster or cooling the hive in summer. Small colonies have difficulty defending the hive from intruders. Control parasites—especially Varroa mites—using the least toxic measures available. Breed bees for mite resistance. Avoid moving bees excessively for pollination service. Ask yourself, “Are we stressing our bees?”

--Richard

Roadside Bee Habitat

Wildlife thrive in habitat or cover that includes food, water, places to reproduce, hide from predators, and plenty of space. Much of the habitat for bees and insect pollinators has been altered for use in industrial agriculture, urban and suburban lawns, and paved parking areas and roads. Dr. Marla Spivak of the University of Minnesota Bee Lab and Eric Mader of the Xerces Society spoke recently about pollinator reversing habitat loss. See http://www.minnpost.com/earth-journal/2014/12/keys-saving-our-endangered-bees-may-be-just-lying-along-roadside. They explained that loss of habitat is one of the three important drivers of Colony Collapse Disorder that continues to reduce managed honey bee colonies. The other two are the widespread use of neonicotinoid insecticides and increased virulence of some honey bee parasites, including the Varroa mite, and some fungal infections. Dr. Spivak explained that there has been much discussion involving banning the neonicotinoid insecticides to help the insects, however, she explained that they need “not just habitat but clean, uncontaminated habitat.” To maintain a robust agriculture she stated that “we need to try for a world with both pesticides and pollinators.” Industrial agriculture, involving vast acreage of cropland, offers little food for bees, poisons insects indiscriminately, and destroys their ground nests. Planting borders and untillable farm acreage in flowering, low-maintenance, native perennial plants were given as sources of food for bees and game birds. Planting milkweed can help monarch butterflies, and nitrogen-fixing clover cover crops improve soil fertility. Dr. Spivak’s University of Minnesota Bee Lab will be studying the effects of planting “bee lawns.”

 Dr. Spivak and Mr. Mader suggested that a solution to the loss of bee habitat could be conversion of mowed and sprayed areas along the nation’s highways into bee corridors. Corridors connect our pollinator gardens and pastures, making them much more effective habitats. Planted with native wildflowers, these right-of-ways could well serve our honey bees, native pollinators, birds, and small mammals. The future will see an interest in moving to roadside vegetation management plans to support our pollinators while beautifying our roadways.

--Richard

Neonicotinoids and CCD

Beekeepers have long suspected the role of the neonicotinoid insecticides in the great upsurge of honey bee colony die-offs that have continued since 2006. Named Colony Collapse Disorder, the loss of honey bee colonies has persisted for eight years in spite of efforts by researchers to identify a cause and by beekeepers to replenish their hive numbers. According to the Bee Informed Partnership’s recently released report, http://beeinformed.org/2014/05/colony-loss-2013-2014/, annual losses have averaged an unsustainable level of nearly 30 percent. A relatively small-scale study by Harvard School of Public Health, http://www.bulletinofinsectology.org/pdfarticles/vol67-2014-125-130lu.pdf, reveals interesting findings. Honey bee colonies exposed to either of two low levels of neonicotinoid insecticides, imidacloprid or clothianidin, abandoned their hives during the winter, defining symptoms of Colony Collapse Disorder. This report contrasts somewhat from the results of a previous study on the effect of pesticides that lead to susceptibility to the honey bee gut pathogen, Nosema ceranae. The larger study, reported in PLOS ONE, http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0070182#authcontrib, finds large numbers and high levels of pesticides in honey bee hives. The researchers found 35 different pesticides in sampled honey bee pollen and high levels of fungicides.

Until recently, fungicides, chemicals designed to fight fungal infections, were considered safe for honey bees. Recent studies are finding fungicides to have an adverse effect on honey bee health, often making insecticides and miticides more toxic to bees. In the PLOS ONE study, fungicides were found to lead to Nosema infection. Needless to say, the search for the cause of Colony Collapse Disorder has revealed the complexity of the problem. There are many factors contributing to honey bee health, including nutrition, parasitic mites, pest insects, viral, fungal, and bacterial diseases, and environmental chemicals. Studies are finding insecticides, miticides, fungicides, and herbicides in the bee hives. Combinations of chemicals and breakdown products of chemicals are often highly toxic to bees. Peace Bee Farm has participated in a number of the studies. Today, catalpa trees secrete nectar from the flowers and nectaries on the leaves.

--Richard

Treasure Valley, Idaho

Beekeeper Doug Cleveland and I sit by the wood stove of his Idaho wood shop and compare beekeeping in Idaho’s Treasure Valley with that in the Arkansas Delta. Doug is the president of the large and active Treasure Valley Beekeepers Club with commercial operators, sideliners, and backyard beekeepers gathering in Boise. Treasure Valley is protected by surrounding mountains. Although considerably farther north, the valley’s winter conditions are similar to those experienced in the Arkansas Delta. Treasure Valley, a high desert, supports a diverse agriculture through the use of an extensive system of irrigation canals that carry water from melting snow in the mountains. Throughout the valley, I see pallets of bee hives. Honey bees pollinate large fields of peas, beans, and mint. Treasure Valley spearmint is grown for its aromatic oil in 40 acre fields. Blue wooden boxes house alkali bees that pollinate alfalfa fields cultivated for seed production. The assembly points of commercial beekeeping operations today are littered with dead colonies. Recent reports show over-winter bee colony losses of 50 percent or more. See http://www.nytimes.com/2013/05/03/science/earth/government-study-cites-mix-of-factors-in-death-of-honeybees.html?hpw. Numerous factors seem to lead to the heavy losses of bee colonies, including queen failure, starvation, parasitic mites, winter weather conditions, Colony Collapse Disorder, pesticides, Nosema disease, small hive beetles, and general colony weakness. This US report comes as Europeans ban neonicotinoid insecticides, widely questioned as leading to honey bee colony decline. See http://www.nytimes.com/2013/04/30/business/global/30iht-eubees30.html. Having the systemic insecticides banned in Europe while extensively used in North America, there is the opportunity to make comparisons and study the effect these insecticides have upon honey bees. Let’s hope that independent researchers can learn from this two-year break in neonicotinoid insecticide usage.

Doug Cleveland and I share many beekeeping techniques. We both rely upon the hygienic behavior of resistant strains of bees to remove parasitic mites from the hives. We avoid harsh chemicals, and we both use thymol, derived from the oil of the thyme plant, to reduce colony mite loads. Today’s photo: Treasure Valley bee hives.

--Richard

What Happened to the Hive?

A beekeeper asks for my thoughts about the loss of a colony of bees. He explains, “I had a good sized colony, three boxes high, bottom and part of second were a mix of brood and honey, and top was all honey. Earlier in the summer I had another six inch super on top which was filled.” In late August, finding his hive empty, he explains, “There was no sound, in fact there was not one bee, and there was not one dead bee either. Every bee was gone.” However, on the day before, the hive showed much bee activity. Attempting to understand colony losses is curious and worthwhile.

The complete abandoning of a bee hive, called “absconding,” is not common in the temperate zone unless conditions make the hive completely undesirable. Colony Collapse Disorder has drawn much attention in recent years, but the conditions here don’t fit its definition. With CCD, there is a loss of older adult bees, but the hive is left with a queen, nurse bees, and brood. A very common cause of the loss of a colony of honey bees, however, is colony collapse due to Varroa mite infestation. This is particularly common in the time period of late summer, as in this late August case. Honey bee colonies grow rapidly in the spring to produce large populations of foragers to harvest nectar and pollen while flowers are in bloom. The queen slows her egg laying in the summer and the colony population gently declines. Parasitic Varroa mite populations follow a different pattern. Mites in a bee hive increase in number gradually throughout the year. By late summer bee numbers are declining while mites are increasing. As the Varroa mites bite bees, they spread bacterial, fungal, and viral infections throughout the colony, eventually killing it. Why was there plenty of hive activity the day before? Robber bees were removing honey stores. Today’s photo shows guard bees challenging incoming foragers. Guards are absent from dead hives.

--Richard

Pesticides in Pollen

One of the intriguing aspects of beekeeping is the complexity of the honey bee nest. Beekeepers spend their first year observing the way bees build their nest by secreting beeswax and constructing honeycombs. The combs contain the three stages of developing brood and pollen and honey for food. The pollen is of different colors. Some is wet and darker in color; this is bee bread, food for brood made of pollen mixed with honey. Honey is stored in open cells or cells capped with beeswax. Beeswax cappings vary in color from white to brown. The surface of the cappings may be textured to resemble hieroglyphic writings. Capped brood is similar in appearance to capped honey, but the texture is somewhat gritty. Drone brood cells are dome-shaped; some call them “bullets.” Queen cells hang vertically and resemble peanuts in shape and texture. Queen cell cups are empty bowls facing downward.

After a while one feels that he has seen everything in a bee hive. I was surprised to find frames unlike any I had seen before. They contained cells of sunken, brick-red cappings. When I opened the capped cells, I found that they contained pollen. Pollen is not normally encapsulated in the cells. This condition was first reported by researchers looking for causes of honey bee Colony Collapse Disorder, CCD. The researchers found that bees “entombed” chemically contaminated pollen. See http://ento.psu.edu/pollinators/publications/Entombed. The most frequently detected contaminants were the miticides coumaphos and fluvalinate and the fungicide chlorothalonil. Combinations of certain pesticides are quite toxic to honey bees. The miticides fluvalinate becomes 1000 times more toxic to honey bees exposed to fungicides commonly used to treat cropland, orchards, and home gardens. Studies conducted with hives having entombed pollen found higher rates of mortality. This research did not associate entombed pollen with CCD.  Finding frames of entombed pollen in my Peace Bee Farm hives that are not chemically treated indicates that contaminants are brought into the hive by the bees. Today’s photo: entombed pollen.

--Richard

Pollination by Honey Bees

Half of the managed honey bee hives in the United States are in California in February for almond pollination. California maintains a large beekeeping business, and it receives many truckloads of bee hives from across the country. This huge movement of hundreds of thousands of hives full of live honey bees is one of modern agriculture’s greatest accomplishments. California leads the world in the production of almonds, nuts prized for their taste and as a healthy food. However, almond trees require pollination by bees. It is bluntly stated that an almond tree without honey bees is merely a shade tree. The pollination of almonds and numerous other crops is accomplished by migratory beekeepers who move their bee hives around the country by truck. Honey bees are ideally suited for migratory pollination service due to their behavior. Honey bees, living in large colonies, can be safely trucked in durable wooden Langstroth hives. The honey bee exhibits a foraging behavior known as “flower constancy” in which individual bees forage from the same plant species as long as the plant is secreting nectar or producing pollen. Charles Darwin described this behavior which makes the honey bee an efficient crop pollinator since only pollen from the same species of plant is transferred among flowers. Migratory beekeeping provides the pollination necessary for over ninety food crops, amounting to one third of our human diet.

Moving hives is stressful on the bees, leaving colonies vulnerable to both new and existing honey bee diseases. Some migratory beekeepers experienced great numbers of colony losses. They were the first to detect Colony Collapse Disorder. Some of these beekeepers are also on the forefront of efforts to manage healthy honey bee colonies by culling old honeycombs, limiting chemical uses, and seeking genetically resistant honey bee stock. While moving bee hives around the country spreads pests and pathogens, the movement distributes honey bee genes, a benefit to beekeeping. In today’s picture, Squeaker, our 25-year-old parrot, enjoys her favorite treat, an almond.

--Richard

A New Bee Parasite Found

A phorid fly known to be a parasite of bumblebees and paper wasps has been found to also parasitize honey bees. This fly, recently identified in California and South Dakota, is in the same genus as the “decapitating flies” that parasitize fire ants. The phorid flies, widely found across the US, multiply inside the bee hive and can infect the queen; female phorids deposit eggs into the abdomen of honey bees. Honey bees that are attacked by the phorid fly leave the hive at night and die. Then, the phorid fly larvae emerge from the dead bee and pupate elsewhere. The abandonment of the hive by worker bees is demonstrated in Colony Collapse Disorder, now thought to be caused by the interactions of multiple pathogens and parasites. Both phorid adults and larvae are found to carry honey bee deformed wing virus and Nosema ceranae, two pathogens associated with CCD. The researchers that detected the phorid flies parasitizing honey bees also found the infected bees flying from the hive at night, not a normal honey bee behavior. Honey bees infected with phorid flies were also found flying around lights at night in a manner similar to moths, also not a normal honey bee behavior. A potential threat exists if the phorid fly has moved from bumblebees’ small, seasonal colonies to infect the much larger, year-around colonies of honey bees. The entire report by Core et al. may be viewed at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0029639.

One of the great mysteries of CCD is that not all colonies affected by the multiple suspected stressors--viruses, Nosema ceranae, and pesticides--collapse. Some of the beekeepers who have taken losses from CCD have questioned whether there is a triggering mechanism that brings about the collapse of colonies. The finding of phorid flies parasitizing honey bees may be an important clue to solving the CCD mystery. Today’s photo shows a paper wasp attacking a honey bee hive. A guard bee quickly responds to challenge and repel the intruder.

--Richard

Looking Ahead

The past four years, marked by heavy colony losses, have been costly to beekeepers. News stories have made this a time of expanding awareness among much of the public of the dwindling number of honey bees and the importance of honey bees and other pollinators in producing our food. Hopefully, the next five years will bring about a greater understanding of the conditions affecting honey bee health. Beekeepers will continue to study honey bee biology and try to learn more about the pests and pathogens that attack bees. Concerted efforts will be made to improve plant diversity on farms and public lands. Farmers will modify their tillage and planting practices to provide food and habitat for bees and native pollinators. Beekeepers will fight to resist the importation of bees from foreign countries to lessen the possibility of spreading pests and diseases. Queen bees may be carefully imported to expand genetic diversity. Hopefully, we will learn how to solve beekeeping and environmental problems with lesser use of chemicals. Colony Collapse Disorder will become another controllable condition of the bee yard.

Already, we are seeing an increase in the number of people putting a couple of bee hives in the back yard. They bring ideas and enthusiasm. They attend beekeeping association meetings and learn how bees are affected by humans and how we alter the environment. The hives of these new beekeepers also serve the existing bee colonies by supplying diverse drones to mate with queens. Most new beekeepers in North America build traditional Langstroth bee hives, but many explore other styles. Two writers offer views of bee hives developed in other countries and in earlier days: Buck White’s Bee Hive Journal, http://beehivejournal.blogspot.com/, offers design drawings for numerous bee hives and equipment. Amy Leigh shows bee hives from around the world at http://benefitsofhoneyblog.com/beekeeping-innovations/. She describes Langstroth, National, and Egyptian hives as well as skeps, bee gums, and hollow log hives. Erin Underhill, age seven, feeds a queen mating nucleus hive.

--Richard

The Next Five Years

Four years of study of the great die-off of North America’s honey bees revealed the scope of the losses. No single cause of the honey bee colony losses emerged, however combinations of pathogens appear to be involved when bee hives lose their adult populations. Surveys of beekeepers revealed that over-winter colony losses averaged 30 percent; however, individual beekeepers’ losses varied widely. One fourth of the beekeepers surveyed experienced winter-time losses above 55 percent, and another fourth of the beekeepers had winter losses of 15 percent or less. Replacing lost colonies is expensive, and thirty percent annual losses are not considered sustainable.  If the beekeeping industry cannot be maintained, a large segment of our food production is at risk. The risk increased in the past decades with the arrival of parasitic mites when the feral honey bee colonies which contributed to food crop pollination largely disappeared. What has been learned from the surveys of beekeepers is that losses vary among beekeepers and from one location to the next.

A new five-year study of beekeeping operations is intended to identify the factors that allow some beekeepers to keep bees with low colony losses. The investigation, funded by the USDA’s National Institute of Food and Agriculture, will look at beekeeping management practices and environmental conditions in the bee yard and forage areas. Penn State’s enthusiastic Dennis vanEnglesdorp will lead the project. Those who would like to participate in the project can sign up at http://beeinformed.org/.  The study will employ tools used by epidemiologists studying diseases of humans. As results of the study are gathered, beekeepers will be able to design their own beekeeping program following what works and what doesn’t. Beekeepers will continue to select from their strongest colonies, and, hopefully, over time surviving bees will become resistant to certain pests and pathogens. As an example, honey bee resistance to tracheal mites seems to be spreading in recent years. In today’s photo spring wildflowers abound: bull nettle, buttercups, spring asters, and common vetch.

--Richard

Four Years of CCD

We are four years into the greatest recorded die-off of honey bees. Since the spring of 2007, beekeepers across North America have experienced colony losses averaging 30 percent each year, typically over the winter. Studies of the causes of the losses, known as Colony Collapse Disorder, have been made and continue. Much more is now known about the factors affecting honey bee health. However, a single source of the condition which results in the loss of a hive’s adult population has not been identified. It seems that multiple conditions exist when colonies collapse. The first common element identified with the honey bee die-off is colony stress. Bees may be under stress from confinement due to transportation for pollination service or from nutritional deficiencies caused by weather, lack of bee plants in monoculture agriculture, or from exposure to insecticides and chemical toxins in the environment. Initial reports of the causes of Colony Collapse Disorder identify honey bee viruses, often vectored by parasitic Varroa mites, and a new strain of Nosema disease, Nosema ceranae. Still unanswered is the effect on honey bees of the use in the environment of neonicotinoids, systemic insecticides brought back to the hive by bees foraging for nectar and pollen. Of special concern are imidacloprid and clothianidin. Their safety is strongly questioned by beekeepers. Study, independent of the chemical manufacturers, is needed to assure their safety.

Colony Collapse Disorder has changed beekeeping over the past four years. The public has become acutely aware of the honey bee’s role in producing our food. Beekeepers have adjusted their management practices to control bee diseases and keep colonies healthy. There has been a shift from the use of harsh chemicals for parasitic mite control to less stressful or chemical-free measures. The importation of honey bees into the United States, allowed in 2006, is again blocked. Breeding bees resistant to the effects of parasitic mites is increasingly the promise for healthier honey bees. Today’s photo: foraging pollen from native Arkansas dogwood trees.

--Richard

GMOs and Neonicotinoids

Corn, or maize, is the most widely grown crop in the Americas. A beekeeper asked me if Bt corn and Roundup-Ready corn are dangerous to honey bees. This is among the commonly asked questions as beekeepers are facing annual colony losses of 30 percent. Beekeepers question the safety of chemicals used in the environment and changes in agricultural practices. Bt corn and Roundup-Ready corn are both Genetically Modified Organisms. In Bt corn, a gene is borrowed from the Bacillus thuringiensus bacteria. This modification allows the corn plant to produce its own Bt insecticidal protein. This technology allows for corn production with lesser application of insecticides, as the plant is producing its own insect killer. The effect of Bt corn on honey bees was tested in Germany from 2001 through 2004. Michael Schacker reports in A Spring Without Bees: How Colony Collapse Disorder Has Endangered Our Food Supply, 2008, that Bt crops and GMOs are not correlated with Colony Collapse Disorder. There may possibly be some benefits for bees and other pollinators from the use of Bt technology in corn, as this may lead to a reduction in the use of crop insecticides. Roundup-Ready corn can withstand the herbicide glyphosate. Herbicides, like Roundup, are being tested now; however, results have not been published.

Following the appearance of Colony Collapse Disorder in 2007, the effect on honey bee health is questioned for all chemicals used around bee hives. A relatively new class of insecticides, the neonicotinoids, is highly suspected by many beekeepers as being involved in CCD and honey bee health problems. Among these systemic insecticides are imidacloprid and clothianidin. Of particular concern is the effect upon the bees of a less than lethal dose of a neonicotinoid insecticide when combined with certain honey bee viruses or the newly detected strain of Nosema disease. Honey bee colony collapses often occur in the winter. This winter has seen greater than normal snowfalls in the Arkansas Delta. Today’s photo: common starlings weather the snow.

--Richard

Protection by Behavior

The honey bee genome project told us that honey bees have fragile immune systems with fewer genes associated with their immune system than many other insects. With the individual bees slightly protected, it seems that the honey bee evolved a number of behaviors to protect the health of the colony as a whole. On a warm winter day, with temperatures rising slightly above 50 degrees Fahrenheit, the bees leave the hive to make cleansing flights. Honey bees keep a clean nest, and they never defecate inside the hive. Today’s picture shows honey bees returning to the hive’s entrance, reduced to a small opening for the winter. Occasional warm days allow the bees to leave the hive briefly and reduce the effect of Nosema disease. Other colony health behaviors include the protection of the hive by guard bees, and workers’ removing dead bees from the hive. An important behavior for the protection of the colony involves sick or diseased bees leaving the hive to die, thus not spreading pathogens to healthy bees of the colony. The absence of sick or dead bees has made the study of Colony Collapse Disorder even more difficult.

We are learning more about the mechanisms involved in the spread of Colony Collapse Disorder. Searching for the causes of CCD and its breadth, researchers are looking into the health of native pollinators as well as honey bees. Like the honey bees, a number of these native insect species are declining. Rajwinder Singh, et al reported in PLoS ONE, December 22, 2010, on their investigation into bumblebee health. The report can be read at http://www.plosone.org/article/info:doi/10.1371/journal.pone.0014357. Singh found that bumblebees can carry viruses normally found affecting honey bees. The investigators found that the viruses are transported between the different insect species in the pollen that they collect. Over time, we will learn much about the relationship between the honey bees, the other pollinators, and the environment. This mechanism of transmission of viruses is a key part of the unraveling story.

--Richard

Clothianidin

Clothianidin is an insecticide belonging to a relatively new class of pesticides known as neonicotinoids. These nicotine-based chemicals are systemic in action, meaning that they are taken up through a plant to poison all of its parts. They are of great concern to beekeepers around the world because they poison the nectar and pollen consumed by honey bees and other pollinators. Clothianidin is often coated onto the seed of crops. It is in widespread use in the United States as an insecticide on corn, the nation’s largest crop. Other crops treated with clothianidin include canola, soybeans, sugar beets, sunflowers, and wheat. While corn, a grass, provides no nectar, it does produce a large amount of pollen, which is very attractive to honey bees. The use of clothianidin has steadily increased since its conditional registration in 2003. Beekeepers have experienced heavy winter die-offs from that time to the present.

The EPA quietly presented Bayer with full registration of clothianidin in April of this year following a seriously flawed trial funded by Bayer. The trial, conducted in Canada, placed hives near canola plots treated with clothianidin and untreated control plots. Remarkably, both plots were located so close together that the honey bees had free access to both. EPA scientists questioned the validity of the trial. Others experts analyzing the trial found significant flaws in its design: corn produces much more pollen than does canola; corn pollen is more attractive to honey bees; and canola is a minor crop in the US, while corn is the most widely planted crop. The neonicotinoids, including imidacloprid, are suspected by beekeepers and many scientists as contributing to honey bee colony collapse disorder. Clothianidin is a persistent pesticide, meaning that it remains in the environment for a long time, and the pesticide is highly toxic to honey bees. You may read the report at http://www.grist.org/article/food-2010-12-10-leaked-documents-show-epa-allowed-bee-toxic-pesticide-. Without independent investigation, the neonicotinoids remain suspects in colony collapse disorder. Clothianidin is banned in Germany, France, Italy, and Slovenia.  Today’s photo: clothianidin-treated corn.

--Richard

Nature Deficit Disorder

Four years into the largest die-off of honey bees that has been recorded, we are finding how resilient the honey bees and the people who tend to them are. One of our followers sent me at link to a presentation recorded in the summer of 2008 by one of the researchers working to uncover the causes of honey bee Colony Collapse Disorder. Though some time has passed since the recording was made, the conditions, driven by pesticides, toxins, and disease, described in 2008 remain accurate today. Dennis VanEnglesdorp, acting as the State Apiarist for Pennsylvania’s Department of Agriculture as well as conducting research at Penn State University, passionately describes the condition of beekeeping in America. Bees serve us in a most important way: We rely upon the honey bee to provide one bite out of every three that we eat. This is accomplished by honey bees completing the reproductive step of pollination of our flowering crops. The bees that do this work are carried about the country on trucks by a group of crafty, determined migratory beekeepers. In spite of heavy losses, they have been able to maintain colony counts by splitting hives each year.

VanEnglesdorp asks why bees are now suddenly susceptible to the conditions that result in CCD. He mentions the heavy dependence our agriculture places upon pesticides. Studies are being conducted to identify the pesticides found inside bee hives. Interestingly, some of the hives with the greatest amount of pesticide are healthy. Some beekeepers attribute this to the deadly result of having too many parasitic mites in a hive. Possibly, those beekeepers who used pesticides heavily in the hive more effectively controlled the Varroa mites and the viruses that they vector. VanEnglesdorp describes our environment as suffering from “Nature Deficit Disorder.” To help correct this situation, he suggests we “make meadows, not lawns.” I photographed a mule deer eating fireweed, a famous honey source, in a Wyoming meadow. Hear VanEnglesdorp’s enthusiastic 16-minute presentation at www.ted.com/talks/lang/eng/dennis_vanengelsdorp_a_plea_for_bees.html.

--Richard

Thymol Treatment for Varroa

Varroa mites were first detected in the United States around 1987. These visible parasitic mites followed by just three years the detection of microscopic mites that live in the trachea, or breathing tubes of the honey bee. The two species of mites decimated honey bee colonies. For a number of years it was common to not see a single honey bee in a stand of clover on a warm spring day when foraging bees should be abundant. Over the next couple of decades, tracheal mites became less of a killer of honey bees, but Varroa mites remained the most deadly pest of bees. Varroa mites puncture the exoskeleton of the honey bees and suck the bees’ blood, called hemolymph. The resulting wound exposes the bees to a number of viruses; several are suspected of being associated with Colony Collapse Disorder. In an attempt the stop the deaths of honey bee colonies, beekeepers relied upon chemical miticides to kill the parasitic mites. This was a most difficult task of attempting to kill a pest on a living insect without harming the insect. Each of the available miticides killed parasitic mites effectively for a while, and then strains of mites resistant to the chemicals replaced the original mites. Other strategies now being preferred include the use of “softer” agents, like organic acids and essential oils.

In the photo, I am inspecting a frame from the center of the brood nest. Here, bees are completing their last brood cycle of the year. In the center of the frame, a few capped cells hold pupae ready to emerge as adults. Around these capped cells are the empty cells of recently emerged bees. Farther out, a band of worker bees tend to uncapped honey. The outside edges of the frame contain honey capped with beeswax, the colony’s stored food for winter. Photographer and beekeeper, Brandon Dill, www.brandondillphotography.com, took this picture of me wearing protective gloves to apply thymol to treat a hive for mites.

--Richard

Investigating Nosema Disease

Nosema disease is receiving considerable attention, because it is now being seen as possibly associated with honey bee Colony Collapse Disorder. As researchers began their study of all known honey bee pathogens in their search for possible causes of the large-scale die-off of honey bee colonies that started in 2006, they discovered that a new strain of Nosema disease was present In the United States. The new strain, known as Nosema ceranae, is thought to have originated with the Asian honey bee. Our honey bees, of European origin, have carried another strain of this bee disease, Nosema apis. This microorganism, which has been reclassified several times and is very similar to a fungus, causes dysentery in honey bees. Now, surprisingly, the original strain has been largely replaced by the new strain. Nosema apis has easily identified symptoms, mainly waste streaking on the hive; Nosema ceranae shows no symptoms. Nosema apis is normally a winter time disease; Nosema ceranae affects bees throughout the year. While Nosema apis was rarely considered a serious condition, Nosema ceranae seems to be much more lethal. Honey bees affected by Nosema ceranae have a shortened lifespan. For honey producers, this results in a lesser number of foragers and reduced honey harvests. The new strain is being reported to exist along with certain viruses in collapsing honey bee colonies. Both strains can be controlled by Fumagillin, our only available treatment.

Researchers at The University of Tennessee are among those studying Nosema disease. At the recent Tennessee Beekeepers Association’s annual conference, Dr. John Skinner and entomology graduate students Michael Wilson and Paul Rhoades demonstrated how to remove the honey bee mid-gut and examine the contents for Nosema spores. Like American foulbrood and chalkbrood, Nosema is a spore-forming pathogen. Nosema exists in both vegetative and spore-producing states. Microscopic analysis of infected honey bees often reveals millions of reproductive Nosema spores. In the photo Paul removes the mid-gut of a honey bee. Beekeeper Shirley Murphy observes in the background.

--Richard

Chemicals in the Environment

The world that you and me and the honey bees live in is being sprayed, coated, and drenched with chemicals. Agricultural fields, lawns, and golf courses are treated with chemical fertilizers, herbicides, and pesticides to produce larger crops, and greener, weed-free grass. The visible effects of this level of chemical use can be measured in more food crop yield per acre of farmland, less fuel consumed tilling the soil, crops available for conversion into alcohol for fuel, and greener lawns and golf courses. Some of the less visible effects of today’s chemical use include weeds becoming resistant to herbicides; pests becoming resistant to insecticides, miticides, and other pesticides; water quality affected by chemical run-offs; soil damaged by persistent chemicals; increased monoculture farming; the loss of pollinator forage and habitat; and the compromising of honey bee immune systems.

While the recent report of one scientific study of honey bee health pointed to a lethal combination of Nosema disease and Invertebrate Iridescent Virus, beekeepers who have been following the CCD investigation are asking questions about the findings. Particularly troubling to some is the lack of mention of certain insecticides that have been suspected of damaging the honey bees’ immune systems. Many beekeepers in Europe and North America feel that the neonicotinoids, like Imidacloprid, have not been proven to be safe for honey bees. To add to the lack of trust among beekeepers, some are questioning the conflict of interest between researchers and chemical companies. For example, see http://money.cnn.com/2010/10/08/news/honey_bees_ny_times.fortune/index.htm. Regardless, any scientific investigation must be able to stand up to scrutiny. Confidence in tests is built by repeating the tests and increasing the number of samples taken. The association between Nosema disease and IIV Virus in collapsing honey bee colonies needs further study. The connection between sub-lethal exposure levels of Imidacloprid and honey bees’ immune systems certainly needs independent study. Today’s photo: An aerial applicator sprays insecticides to kill soybean loopers. Insecticides and fungicides are questioned as having weakened honey bees.

--Richard