Imidacloprid detection and aversion in Bombus impatiens

Imidacloprid is a commonly used neonicotinoid insecticide, as it's thought to kill unwanted insects, but not harm bees. Recent studies have shown, however, that even sub-lethal doses of imidacloprid harm bumblebees through far-reaching effects. These studies demonstrate that the previously assumed bee-safe insecticide may be contributing to the global decline in the bee population. In this study I sought to investigate the possibility of bees detecting, and becoming addicted to, imidacloprid. I conducted asix day trial with three groups: an imidacloprid exposure group (bees consumed an increasing concentration of imidacloprid combined with a decreasing concentration of sucrose), a sucrose-fade group (bees consumed a decreasing concentration of sucrose), and a drug nave group (bees consumed 1 mol l-1sucrose). The imidacloprid concentrations ranged from 0 nmol l-1to 4 nmol l-1(aq). The sucrose concentration ranged from 0 mol l-1to 1 mol l-1(aq). Bees were fed 1 mol l-1(aq) every morning, and fed their treatment nine hours later. The results of this study suggest that bees are able to detect imidacloprid, show an aversion towards imidacloprid, and instead strongly prefer solutions with sugar. These results contradict a previous study which suggests that additional factors may need to be considered when studying the possibility of imidacloprid detection and preference in bumblebees