Timing of Irradiation and Male Mating History Effects on Female Remating in Anastrepha ludens (Diptera: Tephritidae)

Abstract

For the sterile insect technique to be successful, sterile males need to mate with wild females, transfer an ejaculate and inhibit females from remating. This study evaluated the capacity of irradiated Anastrepha ludens (Loew) (Diptera: Tephritidae) males of the genetic sexing strain Tapachula 7 (Tap-7) for inducing the sexual refractory period (time between the first and second mating) of wild females. The following factors were evaluated: 1) irradiation versus no irradiation of male pupae, 2) the age at which male pupae were irradiated (72, 48, and 24 h before adult emergence), and 3) male sexual experience (virgin, once mated, and twice mated). There was no effect of irradiation or age at irradiation on male ability to inhibit female remating or on sexual refractory period. However, wild females had shorter refractory periods when mated with virgin Tap-7 males, compared with males that previously had mated once or twice. We suggest that because inhibition of remating in A. ludens is determined by the full male ejaculate, virgin Tap-7 males are probably delivering smaller ejaculates compared with sexually experienced males. This study increases our knowledge of the reproductive biology of the genetic sexing strain of A. ludens.