Location: Carl Hayden Bee Research CenterTitle: Agricultural landscape and pesticide effects on honey bee (Hymenoptera: Apidae) biological traits
|ALBURAKI, M. - University Of Tennessee|
|STECKEL, S.J. - University Of Tennessee|
|WILLIAM, M.T. - University Of Tennessee|
|SKINNER, J.A. - University Of Tennessee|
|TARPY, D.R. - North Carolina State University|
|STEWART, S.D. - University Of Tennessee|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2017
Publication Date: 4/8/2017
Citation: Alburaki, M., Steckel, S., William, M., Skinner, J., Tarpy, D., Meikle, W.G., Adamczyk Jr, J.J., Stewart, S. 2017. Agricultural landscape and pesticide effects on honey bee (Hymenoptera: Apidae) biological traits. Journal of Economic Entomology. 110(3):835-847. https://doi:10.1093/jee/tox111.
Interpretive Summary: Landscape changes in North America have greatly affected the amount of natural forage, such as wildflowers, available to honey bees compared to forage from agricultural crops such as cotton and soybean. In this study groups of hives were placed in different kinds of environments that resulted in bees being exposed to different amounts of natural forage, crop forage and agrochemical exposure. Researchers found that bees in agricultural areas were exposed to more pesticide and other products, but they were able to exploit the food resources in the farms, judging by the amount of food in the hives and by analyzing the pollen. Researchers also monitored hive weight, by either weighing the hives twice per week or just keeping the hive continuously on electronic scales, and found that hives in agricultural areas gained more weight, likely because of the abundance of food when it was available. Hives with access to natural forage had far less forage for most of the study. Internal hive temperature, which is an important measure of colony health, was higher in hives in agricultural areas than those in natural forage areas, probably because there were more worker bees to generate heat, and brood production was higher in those hives as well. Overall, the tradeoff between the presence or absence of agrochemicals in the environment on one hand, and the amount of forage available on the other hand, favored hives with lots of forage, even if pesticides were present.
Technical Abstract: Sixteen honeybee (Apis mellifera L.) colonies were placed in four different agricultural landscapes in order to study the in situ effects of the agricultural and pesticide exposure on honeybee health. Colonies were located in three different agricultural areas with varying levels of agricultural intensity (AG areas) and one non-agricultural area (NAG area). Colonies were monitored for their performance and biological traits over a period of one year. The main surrounding crops were soybean, corn, sorghum and cotton. Colony weight changes, brood production, and bee-nest thermoregulation were comprehensively evaluated. Palynological and chemical analyses were conducted on the trapped pollen collected from each colony and location. Colonies in AG areas had better access to sustainable nutrition sources than those of the NAG area. Colony weight development and brood production were significantly greater in AG areas compared to NAG area. Better bee-nest colony thermoregulation in AG areas’ colonies was also observed, most likely due to relatively larger bee population size. No pesticide residues of concern were identified in trapped pollen, although sublethal doses of imidacloprid and other pesticides were found, mainly in AG areas. Unexplained queen and colony losses were recorded in the AG areas while colony losses due to starvation were observed in the NAG area. Some non-crop flowering plants were identified as bee-attractive and can be enhanced in both AG and NAG areas for pollinator protection programs. Our results indicate that agricultural crops provide a valuable resource for honeybee hives, but there is a trade-off in increased risk of pesticide exposure.