Pulse rates in the songs of trilling field crickets (Orthoptera : Gryllidae : Gryllus)

In cricket calling songs, pulse rate is often the feature that allows femal es to home on the songs of conspecific males while ignoring those of other species. A previous study of the sibling species Gryllus rubens Scudder and G. texensis Cade & Otte from western Florida showed unexpected effects of developmental conditions and parental generation on the pulse rates of thei r songs. The current study tested for these and other effects in G. rubens from Gainesville, FL, and G. texensis from Dallas, TX. In both species, sib ships from different field-fertilized females differed significantly in the effects of rearing environment on the pulse rates of their songs. Tests fo r effects of nymphal diapause and adult age were negative. Hybrids between the two species produced pulse rates intermediate to the rates of the contr ol crosses. Males of G. rubens reared at 32 degrees C produced faster pulse rates (at a standard temperature) than those reared at 25 degrees C. Furth ermore, pulse rates of field-collected males in this study and of field-col lected and laboratory-reared males in the previous study increased in rough proportion to the known and estimated temperatures during nymphal developm ent.