Low toxicity crop fungicide (fenbuconazole) impacts reproductive male quality signals leading to a reduction of mating success in a wild solitary bee

Recent reports on bee health suggest that sublethal doses of pesticides have negative effects wild reproduction and ultimately their population growth. Females the solitary horned mason Osmia cornuta, evaluate thoracic vibrations odours males to assess male quality. When certain criteria are met, female accepts copulates. However, these signals were found be modified by in other hymenopterans. Here, we tested whether a commonly used fungicide (Fenbuconazole) impact quality mating success O. cornuta. Males exposed fenbuconazole exhibited reduced an altered cuticular hydrocarbon profile compared control bees. Moreover, less successful than males. Synthesis applications. Our results indicate low toxicity can negatively affect reproductive altering behavioural chemical cues. This could explain decreasing pollinator populations pesticide-polluted environment. study highlights need for more comprehensive approach, including behaviour cues, when testing new cautionary approach already crops.