Richness of termite genera in a semi-arid region (Sertão) in NE Brazil (Isoptera)

Abstract

The genus richness of the termite fauna of a semiarid area (caatinga) in Northeastern Brazil was investigated in the dry season of 1996 and the rainy season of 1998. Eight genera belonging to three termite families (Termitidae, Rhinotermitidae and Kalotermitidae) were found in assessments of termite nests and mounds, investigation of dead wood, and cardboard baits buried 10 cm deep in the soil. The nestbuilder guild was represented by only three genera: Nasutitermes, Constrictotermes and Microcerotermes. Their density (about 1-3 nests ha-1) was very low. In mounds of Constrictotermes, the genus Inquilinitermes is almost invariably found as an inquiline. During the dry season of 1996, wood-inhabiting Kalotermitidae (Neotermes sp.) were abundant in dead branches still attached to the trees. In dead wood on the ground we recorded Heterotermes of the Rhinotermitidae, and Amitermes and Termes of the Termitidae. A relatively high activity of Heterotermes on the baits was recorded within 3 months of exposure. Thus, this site is characterized by a very low genus diversity of termites; nest builders are rare, but soil- and wood-dwelling species are highly active in spite of the adverse conditions (drought) which reign during the larger part of the year.