Disparity in sexual behaviour between wild and mass-reared Mexican fruit flies

The sterile insect technique (SIT) is currently used to control Mexican fruit fly Anastrepha ludens Loew (Diptera: Tephritidae). However, mass-rearing can alter the quality of released males. If males that are mass-reared have behaviours different from those of their wild counterparts, then this may diminish the effectiveness of SIT. Questions remain as to whether wild females may be able to detect the male condition before, during and/or after copulation with a mass-reared male. In the present study, copula duration, female remating, female fecundity and fertility of both mass-reared and wild A. ludens are evaluated. Marked differences are found between mass-reared and wild females. Specifically, mating latency is longer and copula duration is shorter for wild females compared with mass-reared females. Importantly, there are no significant differences in mating latency, copula duration or remating probability between wild females paired with either mass-reared or wild males. All mass-reared females remate, whereas only approximately half of the wild females remate after first mating with either a wild or mass-reared male. Fecundity of wild females mated to either wild or mass-reared males is approximately one-third lower than that of mass-reared females, confirming that mass-reared females may have been selected for high fecundity and are adapted to laboratory conditions. Fertility of females that mate with a wild male for only 10 min is not significantly different from that achieved via a full-length copulation. By contrast, females mating with mass-reared males need copulation durations of at least 40 min to achieve fertility comparable with that achieved via a full-length copulation. The findings of the present study have important implications for A. ludens controlled through SIT and broaden our understanding on the copulatory and post-copulatory behaviours between wild females and mass-reared males.