2011 Annual Report
1a.Objectives (from AD-416)
1: Determine the nutrients in pollen that promote worker longevity.
1.A. Determine the effects of pollen mixtures on worker protein and lipid stores and longevity.
1.B. Characterize the chemical composition of pollen mixtures that optimize worker protein and lipid stores and longevity.
2: Determine the effects of undigested saccharides in high fructose corn syrup (HFCS) on worker physiology and longevity.
2.A. Identify the saccharides in HFCS.
2.B: Determine the effect of saccharides in HFCS on worker physiology and longevity.
3: Evaluate the effects of supplemental feeding on Varroa tolerance, queen production and foraging activity of honey bee colonies.
3.A. Modify the MegaBee diet by adding chemical components that were identified in the pollen mixture analysis.
3.B. Determine the effects of nutrition on Varroa infestation and reproduction in worker and drone cells.
3.C. Determine the role of nutrition on queen production and reproductive potential.
3.D. Evaluate the effects of supplemental protein feeding on the foraging rates of honey bee colonies.
3.E. Improving honey bee immune response to CCD by determining the role of symbiotic microbes in bee nutrition.
1b.Approach (from AD-416)
1. Nutritional value will be evaluated by measuring protein and lipid levels and on bee longevity. The chemical composition of pollens that are more nutritious than MegaBee will be determined.
2. Determine the effects of high fructose corn syrup containing higher saccharides on honey bee longevity.
3. Determine the effects of improved nutrition of the longevity of bees parasitized by Varroa, the reproductive potential of queens, and foraging activity of colonies used for pollination.
The nutritional requirements of honey bees are met by nectar and pollen and the presence of beneficial microbes (bacteria and fungi) that aid in food processing. Colonies used for pollination often experience nutritional stress and are exposed to environmental contaminants such as fungicides applied during bloom. Nutritional stress and contamination of nectar and pollen can cause colonies to be malnourished and communities of beneficial microbes to lack the diversity needed to enact their full function.
We compared the nutritional content (protein and amino acids) of pollen before and after its conversion to bee bread to determine if there were changes in nutritional value. The pH of bee bread was lower than that of the pollen. The protein concentration of the pollen was significantly higher than in the bee bread. Amino acid concentrations also differed between pollen and bee bread. The results indicate that nutrient analysis of pollen might not be as indicative of its nutritional value as an analysis of the bee bread made from it.
Malnutrition is a major cause of colony losses. However, malnutrition especially in its early stages is difficult to diagnose. We are identifying biomarkers associated with nutritional state to detect malnutrition. Based on the presence of these compounds, we can evaluate a colony’s nutritional state and determine the effects on vulnerability to disease and population decline.
Beneficial microbes play an essential role in optimizing nutrition in colonies. We identified key bacterial communities needed by bees for food processing and digestion. We also identified and sequenced multiple bacterial genomes involved in the preservation and digestion of food. The functional roles of these beneficial bacteria are being explored relative to nutritional stress, social immunity, and fungicide contamination.
We documented the effects of fungicide contamination of pollen on queen rearing in colonies. When colonies were fed pollen collected from orchards where fungicides were sprayed, less than 30% were able to rear new queens. The fungicides could be reducing the numbers of beneficial microbes needed for food processing thus causing a reduction in key nutrients needed for queen rearing.
Beekeepers feed sugar syrup to colonies as a carbohydrate source. Our studies demonstrated that when colonies are fed during the winter with sugar syrup made with sucrose, there are higher rates of brood production in the spring compared with colonies fed high fructose corn syrup.
Varroa is the most important pest of honey bee colonies. Studies are under way to determine if the effects of Varroa on adult bee longevity and virus transmission can be reduced through improved nutrition. In addition, under a Cooperative Research and Development Agreement, a product was developed (HopGuard) to reduce Varroa populations in colonies based on the miticidal activity of beta plant acids. An integrated pest management program is being developed that identifies timing of HopGuard application for maximum effectiveness. Use of the product in packaged bees and resulting mite levels throughout the year also is being investigated.
Colonies fed sucrose build faster than those fed high fructose corn syrup. Beekeepers feed high fructose corn syrup on sucrose to colonies as a carbohydrate source when flowering plants are not available. ARS scientists in Tucson, AZ demonstrated that colonies fed during the winter with sugar syrup made with sucrose had greater brood production in the spring compared with colonies fed high fructose corn syrup (HFCS). A high rate if brood production in the spring is important for bulding strong colonies for the pollination of early season crops such as almonds.
Reducing Varroa mite populations with beta plant acids. Varroa is the most important pest of honey bee colonies and causes major colony losses due to parasitism and transmitting viruses many of which are associated with Colony Collapse Disorder (CCD). Beekeepers need new methods to control Varroa because currently registered products are either inconsistent in their effectiveness, harmful to brood, contaminate wax combs, or no longer control Varroa because the mite is resistant. Under a Cooperative Research and Development Agreement, ARS scientists in Tucson, AZ developed a product (Hopguard) that uses beta plant acids to reduce Varroa populations in colonies. A Section-18 emergency registration was issued by EPA and HopGuard is now in commercial production and being use in honey bee colonies.
Sammataro, D., Leblanc, B.W., Finley, J.V., Carroll, M.J., Torabi, M. 2010. Antioxidants in wax cappings of honey bee brood. Journal of Apiculture Research. 49(4):293-301.
Cicero, J.M., Sammataro, D. 2010. The salivary glands of adult female Varroa destructor (Acari: Varroidae), an ectoparasite of the honey bee, Apis mellifera (Hymenoptera: Apidae). International Journal of Acarology. Vol. 36(5):377-386.
Tarpy, D., Caren, J.R., Delaney, D.A., Sammataro, D., Finley, J.V., Loper, G., Hoffman, G.D. 2010. Mating frequencies of Africanized honey bees in the southwestern United States. Journal of Apiculture Research. Vol. 49(4):302-310.
Sammataro, D., Avitabile, A. 2011. Beekeepers Handbook. Cornell University Press. 380 p.
Couvillon, M.J., Hoffman, G.D., Gronenberg, W. 2010. Africanized honey bees are slower learners than their European counterparts. Naturwissenschaften. 97:153-160.
Eckholm, B.J., Anderson, K.E., Weiss, M., Hoffman, G.D. 2011. Intracolonial genetic diversity in honey bee (Apis mellifera) colonies increases pollen foraging efficiency. Behavioral Ecology-Sociobiology. 65:1037-1044.
Anderson, K.E., Wheeler, D., Yang, K., Linksvayer, T. 2011. Dynamics of an ant-ant obligate mutualism: Colony growth, density dependence and frequency dependence. Molecular Ecology. 20:1781-1793.
Sammataro, D., Cicero, J.M. 2010. Functional morphology of the honey stomach wall of European honey bees (Apis mellifera L.). Annals of the Entomological Society of America. 103(6):979-987.