Cuticular structures of the stomodeum in Paulinia acuminata (De Geer) and Marellia remipes Uvarov (Orthoptera : Pauliniidae)

The cuticular lining of the stomodeum in orthopteroid insects usually bears cuticular structures, consisting of ridges, teeth, and spines, which are sometimes fairly complex. In some of these insects, particularly cockroaches and Orthoptera s. str., some of these structures have systematic value, mainly at the higher systematic levels. The cuticular lining of the stomodeum in Paulinia acuminata (De Geer) and Marellia remipes (Uvarov) (Orthoptera : Pauliniidae) (the only 2 genera included within the family) have been studied. Wide differences in the pattern of the stomodeal armature, and also in the shape, size and distribution of the spines in its different parts, are recorded. The proportions and limits of the crop and proventriculus, and the form and spatial distribution of spines and other characters, relative to the ridges, appear to be of taxonomic significance. They indicate that the 2 genera may not be closely related, as has been suggested, based on other evidence. While Marelliaappears to be related to the Acrididae, Pauliniaseems to be isolated from other acridoids, except for certain features in common with Proscopiidae and Eumastacidae.