In the absence of cerci the Corrodentia are more specialized than the Isoptera and Plecoptera, but some of them show a more primitive character in the retention of vestigial maxillulae - the minute pair of jaws that are found behind the mandibles in the Aptera.
A large proportion of the Corrodentia are wingless.
Copeognatha: Corrodentia with delicate cuticle.
Originally, however, the Corrodentia included the order which Enderlein has recently separated as Isoptera (see above).
The Corrodentia retain vestigial maxillulae and two pairs of Malpighian tubes, but the wings are somewhat specialized in the Copeognatha and absent in the degraded and parasitic Mallophaga.
Mallophaga: Parasitic wingless Corrodentia (Bird-lice).
As at present restricted, the Corrodentia include two distinct sub-orders.
The name Corrodentia was first used by H.