Male signalling and lek attractiveness in the Mediterranean fruit fly

Abstract

I tested the null hypothesis that females of the Mediterranean fruit fly, Ceratitis capitata, were equally likely to visit leks composed of males with high versus low mating success. In laboratory trials, the observed distribution of matings among males differed significantly from that expected by chance, owing primarily to the higher than expected numbers of individuals with low (mated 0–1 days over 6 consecutive observation days) or high (mated 4 or more days) mating scores. I termed these two groups as ‘low’ and ‘high’ maters, respectively. In the field, greater numbers of female sightings were made at artificial leks of high maters than low maters. This result apparently reflected a greater calling propensity among high maters. Slopes of female sightings versus calling level did not differ significantly between leks of low and high maters, suggesting that the observed relationship between calling activity and female sightings was independent of male mating status. Following the same protocol, I conducted a second experiment to examine whether males used the signals of conspecific males to locate lek sites and, if so, whether signal attractiveness varied with male mating ability. Attraction of males to calling conspecifics was far weaker than that observed for females, and over five different trials a total of only seven male sightings were made at any of the established leks.