The overall goal of this research is to develop and use genetic resistance or tolerance of honey bees to biotic agents, and to devise management strategies to improve the quality of queen honey bees. This will enhance the economic value of the nation’s honey bees for pollination, honey production, overwintering and hazard resistance. Over the next five years we will focus on interrelated projects with the following objectives: Objective 1: Identify and evaluate traits, strains, and stocks for improved honey bee health, e.g., improved immunity, tolerance, or resistance to Varroa and tracheal mites, the fungi Nosema and chalkbrood, and viruses. Sub-objective 1A: Evaluate the potential for viral resistance. Sub-objective 1B: Establish and characterize genetically and functionally distinct lines that differentially respond to Nosema. Sub-objective 1C: Evaluate the potential of worker brood to suppress reproduction by Varroa. Sub-objective 1D: Determine the effect of Varroa infestations on honey bee behavior. Sub-objective 1E: Evaluate immune and stress related responses in selected honey bee stocks. Objective 2: Characterize genetic and physiological aspects of important traits, strains, and stocks and their interaction with biotic and abiotic stressors. Sub-objective 2A: Characterize the chemical ecology of VSH to aid the development of a practical selection method. Sub-objective 2B: Understand the genetic basis of Ascosphaera apis (chalkbrood) resistance observed in RHB larvae. Sub-objective 2C: Genomic sequencing of multiple stocks of honey bees. Sub-objective 2D: Differential responses to Nosema in honey bees. Objective 3: Conduct traditional and marker-assisted breeding and develop management tools for improved bees. Sub-objective 3A: Develop and use improved methods to evaluate Varroa-resistant phenotypes. Sub-objective 3B: Determine management methods using ionizing radiation to increase honey bee colony fitness. Sub-objective 3C: Evaluate autogrooming as a common resistance mechanism towards tracheal and Varroa mites. Sub-objective 3D: Use traditional and marker-assisted selection programs to improve honey bees with VSH-based resistance. Objective 4: Improve knowledge of the biology, physiology, genomics, and behavior of pests (i.e. mites and the small hive beetle) that may be useful for improving their management. Sub-objective 4A: Elucidate the Nosema infection process. Sub-objective 4B: Understand effects of resistance level on Nosema infection across honey bee life stages. Sub-objective 4C: Identify new methods to limit SHB population growth in honey bee colonies.
The health and availability of honey bees (Apis mellifera) have been diminished by multiple biological problems, most notably the parasitic mite Varroa (V.) destructor. Other important threats include fungi (Nosema spp. and chalkbrood), viruses, small hive beetles and tracheal mites. Some of these interact and result in mortality described as colony collapse disorder (CCD). The major goal of this project is to mitigate these threats by finding and selecting for genetically based traits of honey bees that confer resistance to the biological problems. Scientist also will improve management techniques and describe pest biology related to control. Most research targets V. destructor. Efforts that build on our prior work with Varroa-resistant honey bees include using knowledge about Russian Honey Bees to find new traits that enhance resistance, and to improve selection methods. Honey bees with Varroa sensitive hygiene are undergoing traditional and molecular-marker-assisted selection. Novel traits for Varroa resistance also are being sought. New selection of honey bees will target Nosema ceranae and Deformed Wing Virus because these pathogens are thought to contribute significantly to colony losses. Research with Nosema, viruses, tracheal mites and chalkbrood will culminate in development of molecular markers for resistance factors. Management research will expand promising preliminary findings about queen and drone health associated with the irradiation of comb in mating colonies The products of this research -- knowledge and technology -- will strengthen integrated pest management strategies for controlling honey bee pests and diseases. This in turn should lead to better profitability for beekeeping and crop pollination.
This is the second year of this project. We currently are in the middle of the active field research season and all projects are satisfactorily underway with some publications now being developed. Publications are listed that reflect accomplishments for prior projects and include cooperative work with other units.
1. Several factors have effects on Small Hive Beetle reproduction. A diet of brood, pollen and honey produces the highest reproductive rate, temperature found in active bee colonies maximized reproductive rate and females in a population having twice the number of males had higher fecundity.
2. Russian honey bees have a high expression of Varroa Sensitive Hygiene. Two separate assays of Varroa Sensitive Hygiene (VSH) gave similar results suggesting that a simple measurement of brood removal may be a useful alternative method of measuring the behavior. Genetic mapping indicated that the VSH trait in Russian honey bees is controlled by the same gene locus found in other VSH honey bees but with an allele that has a separate lineage.
Khongphinitbunjong, K., De Guzman, L.I., Tarver, M.R., Rinderer, T.E., Chen, Y., Chantawannakul, P. 2014. Differential viral levels and immune gene expression in three stocks of Apis mellifera induced by different numbers of Varroa destructor. Journal of Insect Physiology. 72:28-34.
De Guzman, L.I., Rinderer, T.E., Frake, A.M. 2014. The effects of diet, mating duration , female to male ratios and temperature on ovary activation, mating success and fecundity of Aethina tumida. Apidologie. 46(3):326-336.
Kirrane, M.J., De Guzman, L.I., Holloway, B.A., Frake, A.M., Rinderer, T.E., Whelan, P.M. 2015. Phenotypic and genetic analyses of the Varroa Sensitive Hygienic trait in Russian Honey Bee (Hymenoptera: Apidae) colonies. PLoS One. 10:0116672,doi:10.1371.
Chapman, N.C., Beekman, M., Allsopp, M.H., Rinderer, T.E., Lim, J., Oxley, P.R., Oldroyd, B.P. 2015. Inheritance of thelytoky in the honey bee Apis mellifera capensis. Journal of Heredity. 114(6):584-592.
Chapman, N.C., Harpur, B.A., Rinderer, T.E., Alisopp, M.H., Zayed, A., Oldroyd, B.P. 2015. Hybrid origins of Australian honey bees (Apis mellifera). Apidologie 47(1):26-34
Buawangpong, N., De Guzman, L.I., Khongphinitbunjong, K., Frake, A.M., Burgett, M., Chantawannakul, P. 2015. Tropilaelaps mercedesae and Varroa destructor: prevalence and reproduction in concurrently infested Apis mellifera colonies. Apidologie doi: 10:1007/s13592-015-0368-8.