The forewings have at least a single longitudinal nervure - often two - reaching from base to tip of the wing.
There is no ovipositor, and the wings are either without nervures or have only a single degraded longitudinal nervure which does not reach to the tip. While the Terebrantia are (After H.
At this fold the median nervure stops and is joined by a cross nervure to the radial, which can be distinguished throughout its length from the subcostal.
The other wing consists of a rigid nervure in front and behind of thin parchment which supports fine rods of steel.
Close to a transverse fold near the base of the wing, the median nervure divides into branches which extend to the wing-margin; there is a second transverse fold near the tip of the wing, and cross nervures are altogether wanting.
From another hinder trunk arise the two-branched cubital nervure and three separate anal nervures.
The hind-wings, when developed, are characteristic in form, possessing a sub-costal nervure with which the reduced radial nervure usually becomes associated.