Estrutura da comunidade de abelhas (Hymenoptera: Apoidea: Apiformis) de uma área na margem do domínio da caatinga (Itatim, BA)

Abstract

Several standardized surveys of bee communities undertaken in Brazil in the last few decades have allowed a comparative approach to the search for generalized patterns of community structure. In this paper the results of a standardized year-round bee survey undertaken in Itatim, Northeastern Brazil, in the semi-arid caatinga domain (12° 42'S; 39° 46'W) are presented. The main objective was to investigate the composition of community, the relative abundance of the species and their flight periods. Bees were collected monthly, from september/1996 to november/1997, totaling 180h. The total of 1189 specimens were collected, belolging to 60 species. Apidae was the most diversified family, with 37 species. The genera with more species were Centris Fabricius, Megachile Latreille, and Xylocopa Latreille. A high dominance was observed, as in most of caatinga areas already studied. Apis mellifera L. was the predominant species, with 51% of the total number of individuals captured, and occurred all year long. The other predominant species had a much lower abundance, as: Dialictus opacus (Moure) (6.2%), Perditomorpha sp. (4.0%), Trigona spinipes (Fabricius) (3.8%), Frieseomelitta languida (Moure) (3.7%) and Xylocopa grisescens Lepeletier (3.0%). It is suggested that some characteristics of the community are due to its ecotonal nature, as the presence of some species with a probable marginal occurrence in the caatinga, and the extended period of flight activities of Megachilidae, Halictidae and Colletidae, resulting in a high number of species in activity during the driest four months of the year.