Monitoring colony-level effects of sublethal pesticide exposure on honey bees

Authors: Meikle, William; Weiss, Milagra

Submitted to: Journal of Visualized Experiments
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/18/2017
Publication Date: 11/15/2017
Citation: Meikle, W.G., Weiss, M. 2017. Monitoring colony-level effects of sublethal pesticide exposure on honey bees. Journal of Visualized Experiments. doi: 10.3791/56355.
DOI: https://doi.org/10.3791/56355

Interpretive Summary: Just as continuously monitoring pulse, respiration, blood pressure and other aspects of metabolism and health is becoming commonplace in the medical and sports community, continuously monitoring physical aspects of bee colonies, such as weight, temperature, humidity, sound, and forager traffic, is becoming feasible for most researchers as cost and size of electronic sensors decrease while their precision and capacity increase. This approach to honey bee colonies is logical because data from sensors can be obtained with little or no colony disturbance and because the entire colony can be disassembled and reassembled, if done carefully and rapidly, with few or no adverse effects. The weight and internal temperature of bee colonies given different sublethal doses of a popular neonicotinoid pesticide, including one dose that was very low, were monitored over several months. Colony differences, particularly at the very low dose, that were difficult to detect using periodic inspections were observed using continuous data.

Technical Abstract: The effects of sublethal pesticide exposure to honey bee colonies may be significant but difficult to detect in the field using standard visual assessment methods. Here we describe methods to measure the quantities of adult bees, brood and food resources by weighing hives and hive parts, by photographing frames, and by installing hives on scales and with internal sensors. Data from these periodic evaluations are then combined with running average and daily detrended data on hive weight and internal hive temperature. The resulting datasets have been used to detect colony-level effects of imidacloprid applied in a sugar syrup as low as 5 ppb. The methods are objective, require little training, and provide permanent records in the form of sensor output and photographs.