Effects of leaf extracts of Azadirachta excelsa on Coptotermes curvignathus (Isoptera : Rhinotermidae)

Extracts from leaves of Azadirachta excelsa. (Jack) Jacobs, (Meliaceae) ext racted with solvents, acetone, hexane and methanol were tested on subterran ean termite, Coptotermes curvignathus Holmgren (Isoptera: Rhinotermitidae). The termite workers responded differently to soils and pine blocks treated with varying concentrations of the extracts. The soils treated with the ex tracts did pose a hindrance to the tunneling activities of the termites. Th e termites, however, became insensitive towards the extracts upon a longer period of exposure. The wood mass loss varied significantly with the concen tration of extracts in the wood blocks. In general the rate of survival and wood consumption were reduced when the termites were exposed to high conce ntrations of the extracts. The experiment thus shows that extracts from A. excelsa leaves had an inhibitory effect on subterranean termites, C. curvig nathus.