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

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