Influence of methoprene and dietary protein on maturation and sexual performance of sterile Anastrepha ludens (Diptera:Tephritidae)

The success of the sterile insect technique (SIT) requires the release of males that can compete with wild males. Elevated juvenile hormone (JH) levels and hydrolysed yeast-enriched adult diets improve the sexual attractiveness and competitiveness of sterile male Anastrepha ludens (Loew; Mexican fruit fly), used in large-scale SIT programmes in Mexico and Texas. We applied methoprene (a JH analogue) to A.ludens using two methods, topically on individual sterile adults and mass- immersion of pupae after irradiation. Hydrolysed yeast was either used dry or in agar blocks. Laboratory and field cage experiments were conducted to compare male maturation and sexual performance when males exposed to four different treatments competed for females: (M+P+) application of methoprene and sugar plus hydrolysed yeast as adult food; (M+P-) application of methoprene and sugar only as adult food; (M-P+) no application of methoprene and sugar plus hydrolysed yeast as adult food; and (M-P-) no application of methoprene and sugar only as adult food. Methoprene and hydrolysed yeast accelerated the male sexual maturation from 9 to 5days after the emergence. Combined application of methoprene and hydrolysed yeast had a significant effect on increased male sexual performance in both laboratory and field cage tests. Methoprene application also accelerates female maturation, although less than in males. The substantial improvements in male sexual performance and sexual maturation that can be obtained by incorporating the use of JH analogue and hydrolysed protein, and the development of techniques for their practical application on a large scale, can contribute to a more cost-effective deployment of sterile male Mexican fruit flies in SIT programmes.