(sub-genital plate) is borne on the ninth sternum. In the female there are ten tergites. The supra-anal plate is fused to tergite ten as in the male. There are seven sternites and the sub-genital plate is attached to sternite seven.

The terga and sterna are undivided shields linked together by intersegmental membranes, while the pleura are membranous and lacking in clearly differentiated sclerites. The first abdominal tergum is joined to the metathorax (metanotum) by an intersegmental membrane, but the first abdominal sternum is firmly attached to the metasternum. The pleura and sterna are thickly clothed with setae, but there are far fewer setae on the terga. The eight abdominal spiracles are located in the tergo-pleural membranes below the abdominal terga.