Submitted to: Journal of Insect Physiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/28/2009
Publication Date: 10/1/2009
Citation: Aluja, M., Rull, J., Sivinski, J.M., Trujillo, G., Perez-Staples, D. 2009. Male and female condition influence mating performance and sexual receptivity in two tropical fruit flies (Diptera: Tephritidae) with contrasting life histories. Journal of Insect Physiology. 55:1091-1098. Interpretive Summary: How often female and male fruit flies mate is an important component of designing Sterile Insect Technique releases. That is, the likelihood that mating with a sterile male will leave the female unwilling to mate again influences how many sterile males must be released to “overflood” the wild female population. Scientists at the USDA-ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, in collaboration with colleagues from the Instituto de Ecologia (Veracruz, Mexcio) examined what male characteristics most effected female remating in two pestiferous and potentially invasive fruit flies. Male diet was important, perhaps because it allowed the production of chemicals in the ejaculate. Interestingly male and female size was also an important factor. These results give further reasons for the expensive addition of protein to the diets of mass-reared flies destined for sterile release.
Technical Abstract: Recent recognition of widespread polyandry in insects has generated considerable interest in understanding why females mate multiply and at identifying factors that affect mating rate and inhibit female remating. However, little attention has been paid to understanding the question from both a female and male perspective, particularly with respect to factors that may simultaneously influence female remating rates. Here, we report on a study aimed at ascertaining the possible interactive effects that male and female size and diet, female access to a host and male and female fertility level could have on mating latency, probability, duration and female refractory period using two tropical fruit fly species with contrasting life histories as study objects. Of all factors tested, adult diet played the most significant role. Both Anastrepha ludens and A. obliqua males which had constant access to protein and sucrose mated more often, had shorter copulations and induced longer refractory periods in females than males fed a low quality diet (sucrose offered every third day). Female size and the interaction with male diet determined how quickly female A. ludens mated for the first time. Smaller females mated sooner with low quality fed males than with high quality fed males while there was no difference for large females, suggesting that male choice may be at play if high quality fed males discriminate against smaller females. Copulation duration also depended on both male and female nutritional condition, and the interaction between male diet and female size and diet. Large and high quality fed females had shorter copulations regardless of male condition. Importantly, for A. ludens, female refractory period depended on male size and the nutritional condition of both males and females, which could indicate that for this species, female receptivity does not depend only on the condition of the male ejaculate. For A. obliqua refractory period was associated with the interaction between male size and diet and male diet and host presence. Interestingly, male sterility did not induce shorter refractory periods, whereas sterility in females did. We discuss our results in terms of male ability to inhibit female remating and the relative contribution of female condition on this behavior. We also address the importance of studying effects simultaneously on species with contrasting life histories.