Overview
Adults are mainly nocturnal, but some (e.g.
Prodalmannia variabilis
Bezzi) visit flowers by day. Larvae are mainly parasitoids of adult scarabaeid beetles and adults of several Australian species have been observed ovipositing on
Phyllotocus
and
Anoplognathus
.
Description
Main diagnostic features include:
Incurved lower orbital bristles absent; wing vein R1 extensively setulose above; wing cell cup usually acutely produced; vein C usually without a break or with an inconspicuous break at subcostal position; in female, abdominal tergite 6 resembling preceding tergites; segment 8 elongate and membranous, without longitudinal sclerotised bands; cerci fused with segment 9 to form strong, sharp aculeus.
Most Australian pyrgotids can be distinguished from platystomatids by having either ocelli reduced or absent or abdominal sternites 1 and 2 fused, but the peculiarly elongate
Maenomenus
has neither condition. This genus can be recognised by the short, acute lobe to wing cell cup and the discernible costal break in vein C.
Distribution
Pyrgotids are widely distributed through the warmer parts of the world. With 100 species, the Australian pyrgotid fauna is particularly rich, but still very incompletely described.