FUNCTIONAL FOREWING MORPHOLOGY AND STRIDULATION IN CRICKETS (ORTHOPTERA, GRYLLOIDEA)

Forewing morphology and ultrastructure are analysed in three cricket species (Gryllus campestris, Oecanthus pellucens and Lerneca fuscipennis) and checked in 20 other genera. A strong dorsoventral asymmetry is demonstrated for the first time. The upper side of the tegmina is covered with hexagonal, more or less high crests forming reliefs. On the lower side, annulate, flat and thick veins exist. The distribution of the hexagons and that of the different vein types is uneven on the forewing surfaces. Their significance in forewing functional morphology is discussed in relation to stridulation and to current knowledge on cricket sound production mechanisms. Their extent and distribution, together with the number and strength of the veins and the surface of wing cells, could account for the vibrational characteristics of the cricket forewing and explain the diverse results obtained by several authors on Gryllus and Oecanthus.