Density estimation and optimal sterile-to-wild ratio to induce sterility in Anastrepha obliqua populations

We aimed to estimate population densities of Anastrepha obliqua (McQuart) (Diptera: Tephritidae) from trap data by releasing known numbers of sterile adults into mango orchards, and to determine sterility induction through the use of different sterile-to-wild ratios in field cages. Population densities were monitored with Multilure traps baited with hydrolysed protein (Captor 300) or BioLure during dry and rainy seasons. There was a positive relationship between the release density of sterile flies and the number of flies trapped per day (FTD index) for both attractants and in both seasons. Captor was the most effective lure. Traps baited with either attractant captured significantly fewer adult flies in the dry season than in the rainy season. A 10:1 sterile:wild ratio induced around 80% sterility in A. obliqua cohorts. No significant differences were observed when comparing the release of both males and females vs. only males. These findings can support area-wide integrated pest management programs for application of the sterile insect technique to suppress or eradicate this fruit fly pest.