Seasonal and Site Variation in Costa Rican Euglossine Bees at Chemical Baits in Lowland Deciduous and Evergreen Forests

Abstract

By attracting male euglossine bees with cineole, eugenol, methyl salicylate, methyl cinnamate, and benzyl acetate in Costa Rican lowland deciduous forest and rain forest, we found no indication of change in the composition and numbers of rain forest attractable bee species during different seasons, but within the deciduous forest both abundance and species richness declined in the dry season. Within each major forest type there were substantial differences in the abundance and species composition of attractable bees among habitats: baits in estuarine swamp forest and open pasture in the rain forest attracted very few bees as compared with nearby forest understory sites. In the deciduous forest, at least 15 species of male euglossine bees were attracted that apparently do not have breeding populations in this forest and that do not visit orchids in this forest; we hypothesized that they normally find females and chemical resources elsewhere in distant habitats or forest types.