Odor-Pollution From Fungicides Disrupts Learning and Recognition of a Common Floral Scent in Bumblebees (Bombus impatiens)

Background and Aims Bumblebees provide vital pollination services to both natural agricultural ecosystems. Consequently their declines in species-diversity population size over the last five decades is alarming. Direct contributors these include pesticides, habitat loss, disease. However, given that colony fitness linked foraging success, successful conservation requires mitigation of any anthropogenic practices negatively impact foraging. Previous work has shown agrochemical odor-pollution, including fungicides, can modulate bumblebee behavior. This study investigates how odor pollution from three common fungicides (Safer ® Brand Garden Fungicide II, Scotts Lawn Fungus Control, Reliant Systemic Fungicide) affects Bombus impatiens ’ floral-odor learning recognition using an associative paradigm. Methods The effects fungicide-odor were tested ways: (1) background during learning; (2) recognition; (3) point (localized) recognition. Electroantennogram (EAG) recordings B. confirmed salience all odor-stimuli examined impacts on antennal responses floral-odor. To better understand structure related behavioral data, scents sampled (Solid Phase Microextraction) analyzed gas chromatography–mass spectrometry. Odors then characterized Compounds Without Borders (CWB) vectorization method. Conclusion All disrupted for at least one concentration tested, was universally disruptive concentrations. induced EAG responses, indicating they perceivable stimuli. Interestingly, two (Scotts ) inhibit Monarda fistulosa odor. Odor characterization supports previous findings sulfurous could be odor-driven behaviors. Inability bumblebees associate rewarding floral odors presence fungicidal have negative large-scale implications health reproductive fitness.