Comparison of three populations of Bactrocera dorsalis for efficacy of vapor heat treatment in mangoes

Phytosanitary treatments approved by the International Plant Protection Convention (IPPC) generally are applicable worldwide without regard for the country of origin of the exported commodity. However, circumstantial evidence suggests that quarantine pests may vary in tolerance to phytosanitary treatments by geographic area. If different populations of the same pest species do vary significantly in tolerance to treatments, schedules in the IPPC phytosanitary treatment standard may need to be region-specific instead of globally applicable. This issue has delayed approval of some temperature treatment schedules. The availability of various tephritid colonies at the Insect Pest Control Laboratory of the Food & Agriculture Organization of the United Nations/International Atomic Energy Agency, at Seibersdorf, Austria, is an ideal opportunity to compare species and populations of tephritids for multiple factors including tolerance to phytosanitary treatments. This research compares 3 populations of Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) (China, Kenya, and Thailand) for tolerance to vapor heat treatment (47 degrees C and 95% RH for 150-180 min) in mangoes. Although differences were observed at sub-lethal doses, they became non-significant at levels of control required for phytosanitary treatments, indicating that vapor heat treatments may be broadly applicable geographically.