Wing Dimorphism in Field Crickets (Orthoptera: Gryllidae: Gryllus)

Adult Gryllus are either short-winged (hind wings [HW] shorter than fore wings [FW]: HW/FW < 1) or long-winged (HW/FW > 1). Short-winged individuals are flightless, whereas long-winged individuals generally can fly. Hind wings are not shed after flight. Of five species occurring in peninsular Florida, G. ovisopis Walker is always short-winged (mean value of HW/FW ratio = 0.5), G. fultoni (Alexander) is virtually so (for short-winged morph, mean HW/FW = 0.6), G. assimilis F. is always long-winged (mean = 1.5), and G. firmus Scudder and G. rubens Scudder are dimorphic (mean = 0.8 and 1.6 for short- and long-winged morphs, respectively). In the four Florida species that have short-winged morphs, short-winged males had HW/FW ratios 5–15% less than short-winged females. In long-winged G. firmus and G. rubens, HW/FW ratios differed according to female parentage. In short-winged G. rubens, HW/FW ratios increased with body size (as measured by length of pronotum and hind femur).