Bombus microcolonies as a tool for biological understanding and risk assessment

Authors: Klinger, Ellen; CAMP, ALLISON - Us Environmental Protection Agency (EPA); Strange, James; Cox-Foster, Diana; LEHMANN, DAVID - Us Environmental Protection Agency (EPA)

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/3/2019
Publication Date: N/A
Citation: N/A

Interpretive Summary: Bumble bees provide valuable pollination services to many wild and agricultural plants. Populations of some bumble bee species are in decline, prompting the need to better understand bumble bee biology and to develop methodologies for assessing the effects of environmental stressors on these bees. Use of bumble bee microcolonies as an experimental tool is steadily increasing. This review closely examines the microcolony model using peer-reviewed published literature identified by searching three databases through November 2018. Microcolonies have been successfully used for investigating a range of endpoints including behavior, the gut microbiome, nutrition, development, pathogens, chemical biology and pesticides/xenobiotics. Methods for the initiation and monitoring of microcolonies, as well as the recorded variables were catalogued and described. From this information, we identified a series of recommendations for standardizing core elements of microcolony studies. Standardization is critical to establishing the foundation needed to support use of this model for biological response investigations and particularly for supporting use in risk assessment.

Technical Abstract: Bumble bees are important pollinators, but many of the research methods and results used for these bees are based on honey bee specific techniques that do not accurately capture bumble bee biology. One technique that is specifically used with bumble bees is the microcolony. A microcolony is made by taking several female worker bees and putting them into a rearing chamber without a queen. Eventually one female will start laying eggs and a small colony will develop, allowing researchers to test individuals and a colony of bees for effect of many things such as pesticides, poor nutrition, or pathogens. While many researchers use this technique, the variability of experimental setups make it difficult to compare one experimental result to another or to compare findings to the responses of bees in the natural environment. This article compares and contrasts the difference of setting up and using microcolonies; in addition, the types of experiments and captured variables were summarized. Recommendations are made on better standardization of the use of microcolonies to produce repeatable and meaningful results. These recommendations are especially important when evaluating the effects of pesticides on the health of bumble bees.