Meeting Abstract

74-2   13:45 - 14:00  Fungicide odor-pollution negatively impacts floral-odor learning and recognition in the bumblebee Bombus impatiens David, NF; Sprayberry, JDH*; Muhlenberg College; Muhlenberg College jordannasprayberry@muhlenberg.edu

Previous work has shown that agrochemical odor-pollution, including that of fungicides, can modulate bumblebee foraging behavior. This study investigates how odor pollution from three common fungicides affects Bombus impatiens’ floral- odor learning and recognition using an associative learning paradigm. The effects of fungicide-odor pollution were tested in three ways: 1. background pollution during floral-odor learning; 2. Background pollution during floral-odor recognition; and 3. Point pollution during floral-odor recognition. EAG recordings from B. impatiens confirmed the salience of all odor-stimuli and examined impacts of background fungicide-odor on floral-odor transduction. To better understand how fungicide-odor structure related to behavioral and physiological data, SPME sampling and GCMS were used to determine odorant composition of all odors in these experiments. Odors were then characterized using the Compounds Without Borders (CWB) vectorization method. The CWB-angle between the three fungicides and wild bergamot were all above 50 degrees, indicating that fungicide odor should be perceptually distinct. At higher concentrations fungicide odor-pollution was less likely to disrupt learning and recognition of wild-bergamot odor, but at lower concentrations disruption was common. This was true across pollution modalities. All fungicides induced smaller EAG responses than wild-bergamot odor, and fungicide background appears to attenuate responses to wild-bergamot. While disruption of learning and recognition was not uniform across the three tested fungicides, all are capable of disrupting learning and recognition of wild-bergamot. Inability for foraging bumblebees to associate to rewarding floral odors in the presence of fungicidal odor pollution could have negative large-scale implications for colony health and reproductive fitness.