Wikipedia
The Pergidae are a moderate-sized family of sawflies occurring in the Western Hemisphere and the Australasian Region. The Pergidae are, with almost 450 described species, the third-largest family of Symphyta after the Tenthredinidae and the Argidae. Morphologically, most pergids are typically sawfly-like, but the form of the antennae varies considerably in number of segments and from simple to serrate and pectinate or even bipectinate. Sexual dimorphism is common and reflected in differences in type of antennae, colour, and size. Included are some of the few known apterous sawflies, those of the genus Cladomacra occurring in Papua New Guinea and Indonesia, and a species with brachypterous females, Clarissa tasbates, in Tasmania.