Demography of a genetic sexing strain of Anastrepha ludens (Diptera: Tephritidae): effects of selection based on mating performance

Tapachula-7 is a genetic sexing strain of Anastrepha ludens (Loew) (Diptera: Tephritidae) developed for the application of the sterile insect technique (SIT). To improve the sexual performance of this strain, a mass-reared colony was established from males selected for their sexual competitiveness. Males from selected colonies are more sexually competitive than nonselected males. The present study aimed to analyse the demographic changes recorded in the study colony throughout four consecutive generations, comparing this colony with the parental colony and a wild strain. The results obtained showed that, in the selected strain, fecundity increased, whereas survival diminished, compared with the laboratory parental strain. The increases in fecundity rates were observed at the first generation after selection. No changes were observed in the duration of the reproductive period in the selected strain. Compared with wild flies, selected flies had lower life expectancy, earlier and shorter reproductive period, and greater daily fecundity at young ages (10–30 days), although with lower lifetime fecundity rates. The four generations of the selected colony showed similar patterns of survival and reproduction. The better mating performance and the increase in early fecundity suggest that selection could contribute to improve rearing efficiency and SIT effectiveness.