D3181: Effects of chronic chromium exposure on bombus buzz response

Insects comprise the majority of animal diversity and abundance, yet their decline has been documented for several decades. Various factors contribute to this reduction, ultimately leading to reduced resource availability and quality. Plants can absorb contaminants from the surrounding environment and store it in its nectar and pollen, thus chronically exposing pollinators to pollutants. Heavy metals have become a common environmental contaminant due to several human activities, like agrochemical applications and intensive industrialization, causing sublethal effects among numerous bee populations. Social bees, such as bumblebees (Bombus spp.), particularly rely on their cognitive abilities to provide adequate food for their colony, therefore altered foraging behaviors could lead to either complete colony collapse due to starvation, increased brood mortality, and/or decreased offspring output. This project explores the effect of heavy metal (chromium) exposure on bumblebee cognition by, visually and acoustically, analyzing their defensive buzz response to assess a) threat perception, b) buzzing patterns, and c) cessation of agitation. Preliminary results indicate increased buzz duration between unexposed and high dosed (15ppm) bees after 7 days of exposure. These data suggest higher energy expenditure in chromium exposed bees. This could be indicative of reduced forager efficiency in bumblebees as more time and energy is spent on responding to a threat rather than returning to foraging. Further examination will include buzz pattern comparisons, body size analysis, and energy expenditure estimates.