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Archived Latest News December 2013

The materials and information included in this Latest News page are provided as a service to you and do not reflect endorsement by the American Honey Producers Association (AHPA). The content and opinions expressed within the page are those of the authors and are not necessarily shared by AHPA. AHPA is not responsible for the accuracy of information provided from outside sources. 



The Research Program at the USDA-ARS Carl Hayden Bee Research Center
Tucson, AZ

Relevant Research

The Carl Hayden Bee Research Center in Tucson, Arizona, is our second USDA/ARS honey bee lab to be showcased. They had a Visioning Conference back in July for stakeholder input and our advice was well received. The research center has since taken strategic steps to coordinate valuable research for us: the United States beekeeper. This research will address our current challenge of keeping healthy honeybee colonies. Their main focus is nutrition, and how nutrition affects all aspects of colony health even as it pertains to pesticides and diseases. Located near California, there are advantages in the pollination aspect that provides collaboration opportunities with beekeepers. They maintain 200 colonies in Arizona with the intent that these colonies will be expanded to a migratory route. To Gloria’s credit, she has allowed Frank Eichen to tele-commute and keep the remaining 200 colonies from Weslaco in Texas. There is a possibility these colonies may be set up to run as a migratory research program as well. Please read the following for an overview of the Tucson lab:


Research at the Carl Hayden Bee Research Center (CHBRC) is focused on the role of nutrition in colony health. Nutrition affects all aspects of colony growth and survival including brood production, thermoregulation, pheromone production, and foraging. Nutrition also affects immunity at the level of the colony and individual bees. Research at the CHBRC is conducted from molecular, physiological and colony level perspectives to create a complete picture of how colony losses might be reduced by improved nutrition.

The Scientific Staff at the Center has expanded over the past three years and now is composed of 5 Research Scientists. These are: Gloria DeGrandi-Hoffman (Supervisory Research Entomologist and Research Leader), Kirk Anderson (Research Entomologist), Mark Carroll (Research Entomologist), Frank Eischen (Research Entomologist), Vanessa Corby-Harris (Molecular Biologist), and William Meikle (Research Entomologist). There also are two support scientists (Raul Rivera and Diana Sammataro). There are 14 biological technicians and student biological aids and three Ph.D. students from the University of Arizona.

Nutrition Research

Nutrition is the most critical component for maintaining colony health. Pollen provides all of the protein a hive needs. Nurse bees consume pollen and convert it into the protein-rich foods known as royal and worker jelly. This jelly is important because it is the protein source for developing larvae and queens and is continuously distributed throughout the hive. Drs. Kirk Anderson and Vanessa Corby-Harris are studying the effects of pollen and protein deprivation in nurse bees in nutritionally-stressed colonies. By comparing gene expression patterns between well fed and under nourished nurse bees, they hope to develop a suite of markers associated with malnutrition. In addition to these molecular markers, Dr. Mark Carroll is identifying nutritional markers based on changes in odors of larvae and queens. Both molecular and volatile markers could allow nutritional stress to be detected early in the process of malnutrition before serious damage is done. After markers are identified, studies will be conducted in commercial colonies to determine whether and how they change as bees move from one forage type to another, or are fed different protein supplements especially in the fall and overwinter. These markers also could provide key benchmarks to detect nutritional stress following antibiotic and mite treatments, and sublethal pesticide exposure.

A new project beginning this fall and winter will compare colonies fed various protein supplements and those foraging on winter mustard called rapini (Brassica rapa). Though protein supplements can sustain colonies, the benefits on colony health ultimately diminish. If the colonies could have some blooming plants available, nutritional stress might be alleviated and colonies would have a better chance of surviving and building until almond bloom. Rapini blooms in the winter in the southwest and southern California and might supply forage that could reduce winter losses. Growing plants rather than feeding pollen supplements in the winter is a departure from current beekeeping practices. The research team in the DeGrandi-Hoffman Lab is conducting this project because data are needed to demonstrate if there is indeed justification for spending resources on plantings rather than on purchasing feed. We will collect data comparing protein titers, hypopharyngeal gland development, metabolic and immune responses, brood production and adult population size between colonies fed a protein supplement and those foraging on rapini. Data will be collected throughout the fall and winter until almond bloom. The data comparing colony size, health and survivorship will serve as an economic basis for decisions to invest in plantings rather than protein supplements.

Nutrition and Migratory Beekeeping

Perhaps the greatest nutritional stress on colonies is overwinter especially if hives are moved to California for almond pollination. Beekeepers and growers need practical advice for the maintenance of transitory commercial honey bee populations. To accomplish this, Dr Anderson’s research team will implement in spring of 2014, a migratory beekeeping operation in the western United States. The team will experimentally characterize the nutritional, physiological, chemical and microbial changes observed in colonies on different forage crops throughout the year. This strategy will begin to expose the potential causal agents of colony losses. Careful monitoring of all known pathogen and parasite loads, in addition to other critical hive health components will allow for the elucidation of the relationships among different agents and how combinations may result in colony failure/death. As the foundation for these studies, a comprehensive hive quality assay will be developed to collect and collate data about the complete health of colonies. These include hive microbial balance, the Varroa/ virus complex, nutrition, and pesticides. This approach is not without challenges. However, with the collaboration of beekeepers and growers, these studies could provide much needed information on the stress associated with migratory beekeeping and direct us to possible solutions.

Varroa Research

Research on Varroa is being conducted on several fronts. Dr. Frank Eischen is investigating the prevalence of resistance to amitraz by Varroa in commercial colonies. At this point, resistance has not been found in the three commercial operations that were examined. However, more testing is planned.

Dr. Eischen also is investigating the recovery time for colonies heavily infested with Varroa. Heavily infested colonies do not grow as quickly as lightly infested colonies after mite treatments. Improved nutrition following Varroa treatment might improve the recovery of colonies by stimulating brood production and population growth.

The miticide HopGuard® was developed under a Cooperative Research and Development Agreement with J.I. Haas Inc. The product is an effective miticide especially during broodless periods. However, the product can be improved. Gloria DeGrandi-Hoffman’s research team is working on a new formulation that will last longer in colonies and increase its effectiveness when there is brood present.

Beekeepers should be able to control Varroa in their colonies by well timed miticide treatments. A mathematical model of Varroa population dynamics constructed at the CHBRC was used to design miticide treatment schedules to reduce colony losses. We tested the treatment schedules in commercial apiaries and found unexpectedly high Varroa populations in colonies in the fall. Our treatment schedules were keeping mite levels low throughout the spring and summer. The increases in mite populations were not possible based upon population growth parameters that we measured or that are reported in scientific literature. We suspect that either mite reproductive rates are increasing in commercial colonies or the migration of mites among colonies is greater than previously suspected. We are planning to explore both possibilities in studies beginning in the spring of 2014.

Pesticide Research

The effects of fungicides on the ability of honey bees to acquire nutrients from their food and on immune response are being investigated. Previous work showed that sublethal pesticide exposure reduces queen emergence possibly due to effects on immunity. Developing queens in colonies fed pollen with combinations of pesticides and fungicides had high virus titers and many did not emerge from their cells. Our current research is focused on the effects of fungicides on the ability of nurse bees to acquire nutrients from the pollen they consume. Because fungicides are broad spectrum antibiotics, these compounds might be affecting the fungi and bacteria bees use to digest pollen in their guts and also to preserve and process the pollen into bee bread. We are comparing the amino acid compositions of bee bread between colonies fed the same pollen source with and without fungicide contamination. We also are examining protein digestion and energy production in nurse bees and foragers fed pollen and nectar containing fungicides. If there are differences, it could indicate that the ability of bees to obtain nutrients and convert them to energy is compromised when pollen is contaminated with fungicides. This could result in malnutrition even when there are large pollen stores in the colony.

Studies on the effects of sub-lethal pesticide exposure are also being conducted at the colony level. Dr. William Meikle will introduce colonies into almond orchards where fungicides are applied during bloom. The colonies will be continuously monitored for various hive parameters (e.g., weight and activity) during and after almond pollination. A matched set of colonies will be monitored that were not exposed to fungicides. Colonies will be returned to Arizona and post-bloom monitoring will continue. Comparisons of colony growth and disease prevalence will be made between the two sets of colonies. These studies will compliment those investigating the effects of fungicides on nutrient acquisition and energy production.

Dr. Meikle also will study the effects of pesticide exposure on honey bees in the Mississippi Delta. Hive weight and temperature will be monitored continuously, and bees honey and bee bread will be sampled for pesticide contamination before, during and after pesticide applications. Pesticide data from colonies in conjunction with the continuous monitoring will enable us to correlate changes in hive weight and activity with levels of pesticide exposure.

Again, given that nutrition is the direction for this research unit, it should provide useful information to mitigate the loss of bee pastures as well as the effect that pesticides and disease have on colony health. They have an excellent plan to utilize their talents for our current challenges. The mobile research units that are gearing up for migratory studies are exciting. These will provide excellent collaboration opportunities to study what you and I face in our own operations every year. There seems to be great opportunity for this lab to produce positive results in the upcoming years.

By Joe Sanroma

President, Louisiana Beekeepers Association

Executive Board Member, American Honey Producers Association




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Cassie Cox
Executive Secretary
PO Box 435
Mendon, UT 84325