Sublethal effects of piperonyl butoxide, a common insecticide synergist, on bumble bee microcolonies

Piperonyl butoxide (PBO) is a common insecticide synergist used in agricultural products throughout the U.S. PBO increases the effectiveness of insecticides by blocking insect detoxification mechanisms. On its own, PBO is considered relatively non-toxic to non-target organisms such as honey bees. However, little research has evaluated its toxicity and sublethal effects on other bees, such as the common eastern bumble bee (Bombus impatiens). Using Environmental Protection Agency (EPA) guidelines, we calculated a field-realistic concentration of PBO and dosed bumble bee microcolonies. Mortality, sucrose consumption, and the total number of brood cells and nectar cups were compared between control and PBO-dosed microcolonies. In general, we found limited effects of PBO on any bumble bee response variable. Future studies should evaluate a larger range of field-realistic doses on bees in addition to measuring other sublethal effects such as behavior and physiology.

These past 10 weeks with the BTI program and the McArt lab have definitely become a highlight in my life. Not only did I get to work with amazing people, but I was able to explore a completely new topic with the unwavering support of my mentor. I found myself corralling run-a-way bees one afternoon, pesticide-dosing bees the next, learning coding languages the following night, and being taught tricks of the trade; truly never a dull moment in the lab! I’ve been adding skill after skill since I arrived and have gained a new appreciation for project troubleshooting and the importance of bee research. I leave with new career and educational perspectives, confidence in my research abilities, and new friends!