The Release of a Small Percentage of Sterile Bactrocera dorsalis (Diptera: Tephritidae) Males Relative to Fertile Males Induces the Collapse of the Progeny Population

The sterile insect technique (SIT) is an environmentally friendly and species-specific method widely used to control agriculturally important fruit flies (Diptera: Tephritide). Previous studies have focused on the effects of releasing a higher proportion of sterile males relative to fertile males on Bactrocera dorsalis populations. In this study, we focused on the impact of releasing a small percentage of sterile males relative to fertile males on B. dorsalis populations. The results showed that when the ratio of wild to sterile males was 1:3, the number of eggs produced within 12 days (5166 eggs) and hatching rate (66%) were significantly lower than those of the control group (6680 eggs and 85%). When the males were released at a ratio of 1:3 for the second time, the hatching and pre-adult survival rates of B. dorsalis progeny were 43% and 37%, respectively. There were also significant decreases in R0, r, λ, and T compared with the control, and after 90 days the population size predicted using the TIMING-MSChart program was reduced by 63%. Overall, these findings indicate that the release of sterile males as a small proportion relative to fertile males resulted in the collapse of the B. dorsalis population. This study establishes a scientific foundation for the release of sterile males in the field and the environmentally friendly prevention and control of B. dorsalis infestations.