The function of environmentally acquired perfume blends in male orchid bees

Perfume making by male orchid bees is a remarkable behavior giving rise to an entire pollination syndrome in the neotropics. Male orchid bees concoct and store perfume mixtures in specialized hind-leg pockets using volatiles acquired from multiple environmental sources, including orchids. However, the precise function and ultimate causes of this behavior have remained elusive. We supplemented male Euglossa dilemma reared from trap-nests with perfume loads harvested from wild conspecifics. In dual-choice experiments, males supplemented with perfumes mated with more females, and sired more offspring, than untreated, equal-aged, control males. Our results demonstrate that male-acquired perfumes function as chemical signals emitted during courtship and received by females when selecting mates. Sexual selection might be a key agent shaping the evolution of perfume signaling. One-Sentence SummaryThe possession of exogenous volatiles increase male mating success and paternity in orchid bees.