Effects of adult-diet modifications on sexual maturation rate, body weight, and quantity of sperm transfer by male Mexican fruit fly (Diptera: Tephritidae).

Mass-reared sterile Mexican fruit flies (Anastrepha ludens [Loew]) are released along the US-Mexico border to control fruit fly damage and spread. It is more cost effective for the mass rearing program if males mature at a younger age because they can be held for a shorter time at the facility before release. In this study, adult male Mexican fruit fly diets were tested to determine if the current diet used at the mass rearing facility promotes younger mating and optimal sperm transfer compared to other diet formulations. Hydrolyzed yeast presentation methods were examined: an agar-free dry mixture of yeast and sugar (Y+S), yeast embedded in the diet during the agar boiling process (current method used) and sifted dry on the ager gel surface. Methoprene, a juvenile hormone analog was also tested as a supplement to agar gel diets with and without yeast. A greater proportion of males fed Y+S mated 1 day earlier than males fed other diets. Male mating age and diet did not significantly affect the quantity of sperm transferred; however, a non-significantly higher percentage of males fed diets with embedded yeast transferred enough sperm to fill all 3 spermathecae. The results suggest that the current diet used is optimal for mass-rearing the flies and that yeast presentation method has a significant effect on A. ludens male mating age but not on the quantity of sperm transferred to females.