Discovery of an apparent male soldier caste in a nest of a halictine bee (Hymenoptera : Halictidae), with notes on the nest

Abstract

A communal nest of Lasioglossum (Chilalictus) sp., excavated in January 1970 in far western South Australia, produced adult bees of three kinds : females, an ordinary male, and highly modified males. The modified males were characterized by relatively very large heads and mandibles, reduced eyes, and small wings which made them incapable of flight. Their gonads and terminalia appeared to be normally developed. The modifications of these males seem appropriate to a subterranean existence and to a soldier-like role in the community. The more ordinary flying males exhibit distinct variation in the relative size and shape of the head and mandibles, those with the largest heads being reminiscent of the soldiers. Some details of the nest and its occupants are provided.