CORRELATES OF MALE QUALITY IN THE FIELD CRICKET, GRYLLUS-CAMPESTRIS L- AGE, SIZE, AND SYMMETRY DETERMINE PAIRING SUCCESS IN-FIELD POPULATIONS

Sexual selection in field crickets (Gryllidae) is well documented. Sev eral studies have identified male traits, such as age and body size, t hat influence pairing success in the field. Here I show how these trai ts covary with male quality by examining the degree of fluctuating asy mmetry in male Gryllus campestris. Older males were both larger and mo re symmetrical. Principal components analysis suggests that these thre e variables were essentially measures of the same trait, male quality. A comparison of paired and calling males showed that males of high qu ality were more successful in obtaining mates; paired males were older , larger, and more symmetrical. The area of the harp covaried with mor phological traits and determined the carrier frequency of the male's c all. Information related to male quality was therefore available for f emale discrimination.