Some of the outermost tubules of the ep06phoron are sometimes distended to form hydatids.
The larvae of this parasite develop in the Malpighian tubules of the insect; at a certain stage they cast their cuticle and make their way into the space - part of the haemocoel - found in the labium.
Lameere's classification is founded on the number of abdominal sterna, the nervuration of the wings, the number of malpighian tubules (whether four or six) and other structural characters.
There are four malpighian tubules.
Except for the absence of 'the longitudinal fibres the skin of the proboscis resembles that of the body, but the fluid-containing tubules of the latter are shut off from those of the body.