Control of the Japanese orange fly, Bactrocera tsuneonis (Diptera: Tephritidae), through several preharvest management practices: establishment of a phytosanitary measure for citrus fruits for export

Abstract

The Japanese orange fly, Bactrocera tsuneonis (Miyake) (Diptera: Tephritidae), is a univoltine tephritid pest of citrus fruits. Its occurrence in citrus-growing regions restricts the export of citrus fruits owing to plant quarantine regulations. We investigated whether the B. tsuneonis infestation rate could meet export quarantine standards if proper preharvest management were carried out. Our approach involved using orchards unsuitable for B. tsuneonis occurrence, implementing appropriate pesticide control, and removing suspected infested fruits. Sunny, open orchards away from any thickets that could serve as hiding places for the adults were chosen as the demonstration orchards. During the peak adult emergence and larval hatching periods, pesticides were sprayed to protect the fruits from infestation. We observed a total of 724,296 fruits throughout the fruit coloring period and removed 1027 suspected infested fruits. We dissected 58,193 harvested fruits and confirmed that they were not infested. No adults were captured during trap surveys in these orchards. In contrast, poorly managed orchards in the same area consistently exhibited fruit damage by B. tsuneonis larvae, and adults were captured in trap surveys. These results prove the feasibility of establishing damage-free orchards through appropriate preharvest management, even in regions where B. tsuneonis is distributed.