The evolution of wing folding and flight in the Dermaptera (Insecta)

The structure of the dermapteran hind wings is described and their hind wing folding is compared with other insect taxa with folded wings (i.e. Coleoptera, Hymenoptera and Blattodea). The peculiarities of the dermapteran hind wing folding are pointed out: the wings are unfolded by the cerci, one wing after the other, in a rather slow process. The antagonistic movement, folding the wings, is achieved by intrinsic elasticity and resilin. The stem group representatives of the Dermaptera, the ‘Archidermaptera’ and the ‘Protelytroptera’, both taxa probably paraphyletic, do show the step-wise transformation from a simple, unfolded, ‘cockroach’-like wing, to the complex wing of Recent Dermaptera.