Orchid bee collects herbicide that mimics the fragrance of its orchid mutualists

Abstract

Abstract Male orchid bees store volatile compounds collected from their orchid mutualists and other sources to use in their courtship. Males of a naturalized orchid bee in Florida, Euglossa dilemma Bembé & Eltz (Hymenoptera: Apidae), intensively and habitually collected from substrates impregnated with triclopyr herbicide, most probably collecting its major breakdown product TMP (3,5,6-trichloro-2-methoxypyridine). Why this occurred and if the practice harmed the bees was considered. The chemical is thought to have low toxicity to bees and orchid bees collect and manage volatile chemicals so that they do not contact the interior of their bodies, both suggesting limited harm from the practice. Molecular similarity comparisons of TMP with 24 volatile compounds collected by E. dilemma found greater than 50 % structural similarities in four compounds according to the maximum common substructure, suggesting that TMP mirrors compounds needed by the bee in its courtship, and probably explains why the bees collect triclopyr. The bizarre but interesting collection of an herbicide by this orchid bee appears to be due to the similarity between the herbicide and chemicals that the bee needs in its courtship. The herbicide does not appear to harm the bee.