Differential Mating Success of Male Wing Morphs of the Cricket, Gryllus rubens

Abstract

-Genetically marked individuals were used to study differential mating success between male wing morphs of the cricket, Gryllus rubens. Previous studies of Gryllus rubens and other wing-dimorphic insects have documented that flightless short-winged or wingless females typically attain reproductive maturity earlier and oviposit more eggs relative to their long-winged counterparts. This study was done to determine if flightless males also exhibit enhanced reproductive characteristics. Segregation analyses documented the genetic basis of allozymes used to infer paternity in subsequent experiments. Control experiments documented the absence of effects on mating success independent of wing morph due to (1) the genetic stock from which males were taken; (2) male size; or (3) female wing morph. Mating trials involving a long-winged male, a short-winged male and a female of either wing morph documented no significant differences in the number of progeny sired by male wing morphs. This pattern was true for both the first group of offspring and for the entire set of offspring produced during a 20-day period. Thus, in contrast to females, we observed no increase in reproductive output in males resulting from the loss of the flight apparatus. However, substantial variance in mating success was observed between males independent of wing morph. This result was likely due to the existence of a dominance hierarchy and the increased mating success of the dominant male.