Nesting behaviour of the Black Digger Wasp,Sphex argentatusFabricius 1787 (Hymenoptera: Sphecidae) in south India

Abstract

A congregation of 72 nests built by 47 females of Sphex argentatus was observed for 107 h. A typical nest had a main burrow and two accessory burrows. The main burrow terminated with a cell at a depth of 46·5 cm. The number of cells per nest varied from 1 to 5. While leaving the nest for hunting, the accessory burrows were left open and the main burrow was temporarily closed. The species mass provisioned the cells with adults and nymphs of Conocephalus sp. (Orthoptera: Tettigonidae). 76·2% of the prey consisted of males. Observations on nest building, functions of accessory burrows and the behaviour of the wasp are presented along with a flow-chart for nest building activities of the wasp.