An evaluation of honey bee (Apis mellifera L.) worker behaviors when exposed to a pesticide-contaminated environment

Honey bees exhibit age polyethism and thus have a predictable sequence of behaviors they express through developmental time. Pesticide exposure can lead to behavioral acceleration, resulting in younger workers transitioning to performing more risky colony tasks, including precocious foraging. This, in turn, can lead to an imbalance in the number of workers performing colony tasks and eventual colony failure. This research examines the relationship between environmental pesticide exposure and colony failure by observing the task-specific behaviors of worker honey bees in observation hives. More specifically, this study assessed potential changes in behaviors of similarly aged workers within two treatment groups: 1) colonies located near point-source pesticide pollution, and 2) colonies embedded within a typical agricultural environment (control). Cohorts of newly emerged sister workers were routinely paint-marked and randomly incorporated into separate treatment hives to establish similar population structures that contained a range of age-marked individuals from newly emerged workers to older foragers. Worker bee tasks were monitored and assessed on a total of eight colonies three times a week for a month to determine potential impacts of pesticide-contaminated environments on worker performance and age-specific tasks critical for normal colony functions.