Comparison of Orchid Bee (Hymenoptera: Apidae) Species Composition Collected with Four Chemical Attractants

Abstract

Orchid bees (Hymenoptera: Apidae: Euglossini) are a diverse and important group of Neotropical pollinators. Numerous chemicals have been used in sampling orchid bees, and species-specific attraction, particularly of males, to these chemicals is well known. However, there have been few studies that have quantified differences in the species composition of orchid bees attracted to particular chemicals. In this study, we compared the abundance and species composition of orchid bees collected with 4 commonly used attractants: benzyl acetate, eucalyptol (or cineole), eugenol, and methyl salicylate. Eucalyptol collected the greatest abundance and species richness of orchid bees. Indicator species analysis revealed that 3 species, Euglossa imperialis Cockerell, Euglossa obtusa Dressler, and Eufriesea mexicana (Mocsáry), were significantly associated with eucalyptol, and 1, Eulaema marcii Nemésio, with benzyl acetate. The multi-response permutation procedure revealed relatively large differences in species composition of orchid bees collected with eucalyptol vs. benzyl acetate and eucalyptol vs. eugenol. Our results showed that eucalyptol and benzyl acetate were the most effective and complimentary attractants, but even less effective attractants such as eugenol may attract novel species.