Mating competitiveness and rate of sexual maturity of gamma-sterile Mediterranean fruit fly males

Abstract

To determine the effects of gamma sterilization with 6, 8, 6, and 10 kr on the sexual maturation rate and copulatory competitiveness of male Mediterranean fruit fly (Ceratitis capitata Wied, Diptera Tephritidae), studies were conducted in the laboratory and field at IICA-CTEI, Tivialba, Costa Rica.

Five hundred fluorescent-powder-marked males (125 in each treatment) were caged with 250 age-matched virgin females. In the field, two-day-old adults were released into 9x9x7 foot cages covering two or three producing coffee plants. In the laboratory, newborn adults (less than 12 hours old) were placed in 1 cubic foot cages

Copulating flies were collected constantly in small bottles (shell vials) between 7 and 16 hours, for the three days following release into the cages. The time of copulation was recorded for each pair. The results demonstrated that irradiation reduces the copulatory competitiveness of males treated with any of the doses tested. The data did not show any delay in the mating rate of sterile males. The copulation frequency, recorded every hour, was similar in treated and normal males throughout the experimental period. The first peak of copulation occurred between 11 and 12 hours in two-day-old males in the laboratory, and around 9 hours in three-day-old males in the field.