Dinâmica de fundação de ninhos por abelhas e vespas solitárias (Hymenoptera, aculeata) em ninhos-armadilha no Semi-árido Nordestino.

Abstract

Dynamics of nest foundation by bees and solitary wasps (Hymenoptera, aculeata) in trap nests in the semi-arid northeast. The community structure of solitary bee and wasp species that nest in pre-existing cavities was systematically investigated at Estacão Ecológica do Seridó, Serra Negra do Norte, RN, from August 2004 to August 2006, using the technique of sampling in trap nests. Ten wooden blocks with 32 holes each were used, 1.5 m above the ground, and cardboard trap nests with 4, 6, 9 and 12 mm in diameter were inspected every 15 days. The capped nests were removed and taken to the laboratory to observe the emergence of adult individuals and possible occurrence of parasites. 359 nests were founded, 46 of nine species of bees, 240 of nine species of wasps and 73 parasitized by 12 species of parasites. Among the nesting bees, the tribe that presented the largest number of species was Megachilini (3). However, the species that stood out the most, in relation to collected nests (21) and emerged individuals (43), Centris tarsara, belonging to the Centridini tribe. Among the nesting wasps, Pachodynerus guadulpensis was the most abundant in number of individuals (104), Trypoxylon lenkoi had the largest number of nests (57) and the genus Trypoxylon the largest number of species (6). Bees showed a preference for a diameter of 9 mm and wasps for 6 mm. There were decreases in the number of bee and wasp nests collected in the dry periods in the two years studied when compared to the rainy periods. In the dry season, the nesting of bees was restricted to places close to water bodies.