Sexual dimorphism in the Hymenoptera

Spectacular sex differences of many kinds occur abundantly among the wasps, bees and ants that make up the insect order Hymenoptera. In some cases these differences are so extreme that males and females of the same species have been classified in different genera for decades, until a chance observation of mating, or emergence from a single nest, establishes their identity. Even where the sexes are similar in morphology they lead very different lives. The hard-working females hunt for prey or other larval provisions, and in many taxa they carry these provisions back to a nest that they have constructed to protect their offspring. The males, by contrast, lead short lives (sometimes nasty and brutish), devoted to the single purpose of inseminating females. Countless variations on this theme have evolved during the long and successful history of the order, and other features of hymenopteran biology have allowed these sex differences of ecology to be translated into equally striking sex differences of behavior, morphology and physiology.