Technical Abstract: Resveratrol is a recently discovered compound. Three concentrations (50, 100, 200 µM) of resveratrol were evaluated against Bactrocera dorsalis and B. cucurbitae by incorporating resveratrol into fruit fly liquid larval diet under the following conditions: 1) with or without wheat germ oil (WGO) in the diet; 2) effects of radiation; 3) with wheat germ oil in the diet and radiation treatment; and 4) with/without wheat germ oil in the diet and no radiation treatment. The results showed that: 1) fruit fly performance dramatically affected by diet without WGO; 2) radiation significantly affects larval duration, adult emergence, adult fliers, egg production, and egg hatch in B. cucurbitae with adult emergence, adult fliers, and egg hatch in B. dorsalis; 3) adult emergence significantly rose in B. dorsalis when 100 µM resveratrol was added, but it did not occur in B. cucurbitae. Adult fliers from resveratrol treated diet were enhanced significantly by the concentration of 50, 100 and 200 µM of resveratrol in B. cucurbitae. Percentage of egg hatch was also increased by 50 µM, but not 100 or 200 µM resveratrol in the diet; 4) decreased egg hatch with the increase of resveratrol from WGO-devoided diet while no effect from WGO fortified diet. Egg production was significantly lower from the 200 µM than 0 or 100 µM of resveratrol from WGO fortified diet. It confirms our findings that 200 µM of resveratrol may be detrimental instead of beneficial.