Mating performance of sterile Mexican fruit fly Anastrepha ludens (Dipt., Tephritidae) males used as vectors of Beauveria bassiana (Bals.) Vuill

Field cage tests were carried out to determine the sexual competitiveness, copulation duration and sperm transfer of sterile and wild Mexican fruit fly, Anastrepha ludens (Loew), males that were treated or not treated with Beauveria bassiana (Balsamo) Vuillemin conidia immediately before mating tests. No significant differences in sexual competitiveness were found between untreated sterile males and sterile males treated with conidia, indicating that the presence of conidia did not significantly reduce mating performance. However, both types of sterile males were less competitive than wild untreated males. There were no significant differences in copulation duration and the quantity of sperm transferred between the two groups of sterile males. A positive correlation was found between copulation duration and the quantity of sperm transferred. The four treatments exhibited significant differences regarding the quantity of transferred spermatozoids stored in the spermathecae but there were no differences in the percentages of total sperm stored in each spermatheca. Our results support the idea of using sterile flies as vectors of B. bassiana conidia in controlling fruit fly populations, while, at the same time, reducing the exposure of and harmful effects on non-target organisms.