No 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.

Females of bee species can present a temporal specialized behavior in the food collection for their offspring. We studied the food of Euglossa townsendi immatures from nests established in trap-nests disposed in a hygrophilous forest in Brazil, between March 2010 and February 2012. The pollinic material remaining in the brood cells were acetolysed and identified by comparison with the pollen of plants that bloomed in the area during the study period. We identified 21 plant species belonging to 14 families in the provision. However, the results indicated that immature of Eg. townsendi feed preferentially on pollen of Miconia chamissois (Melastomataceae) found in 100 % of the samples. Except for two nests, there was a similarity above 85 % in the composition of the supply plants of the brood. We also found a high similarity between the pollinic contents of the cells of each nest. Our results suggest a temporal preference on M. chamissois .