Temporal variation in the abundance of Orchid Bees (Hymenoptera: Apidae) in a Neotropical Hygrophilous Forest

Abstract

Although bees are important pollinators in several ecosystems around the world, studies on bee diversity in hygrophilous forests are scarce. This type of vegetation is restricted to permanently wet soils and, therefore, has particular floristic, structure and physiognomy. The goal of the present study was to inventory and analyze the temporal variation of the euglossine bees that occur in a neotropical hygrophilous forest. In order to sample male bees we used four chemical baits, eucalyptol, eugenol, vanillin, and methyl salicylate. The captures were made once a month, from March 2010 to February 2011, from 9:00 am to 12:00 pm. We captured 113 individuals of three genera and five species (in decreasing order of abundance): Eulaema nigrita Lepeletier, 1841 (n=52), Euglossa pleosticta Dressler, 1982 (34), Exaerete smaragdina (Guérin-Méneville, 1844) (12), Euglossa carolina Nemésio, 2009 (11), and Euglossa fimbriata Rebêlo & Moure, 1968 (4). The most attractive bait was eucalyptol (n=98), followed by vanillin (11), and eugenol (4). Both temperature and rainfall affected significantly the distribution of the number of males throughout the year. The highest number of Euglossini species and individuals was sampled in the warm and rainy season, with activity peaks varying among species.

Keywords

• richness
• abundance
• Euglossini
• chemical baits
• temporal fluctuation