Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/15/2008
Publication Date: 1/15/2009
Citation: Vargas, R.I., Stark, J.D. An Evaluation of Alternative Insecticides to Diazinon for Control of Tephritid Fruit Flies (Diptera: Tephritidae) in Soil. Journal of Economic Entomology. J. Econ. Entomol. 102(1) 139-143 (2009). Interpretive Summary: The pesticide diazinon is being phased out for use in fruit fly eradication progams. This study investigated the usefulness of several alternative pesticides in controlling Mediterranean fruit fly, melon fly, and oriental fruit fly as pupae in soil. From the five products tested, Warrior and Force were shown to be the most effective products compared to diazinon. Further studies were conducted to look at the effect of these two pesticides in different soil types. It was found that Warrior and Force were both more effective in sand than in other soil types. From these studies, the authors conclude that Warrior and Force would both be effective soil treatments for fruit flies.
Technical Abstract: Diazinon has been used extensively in the past as part of California eradication programs for tephritid fruit flies, but is being phased out for this purpose in the United States. Therefore, in this study, the toxicity of Platinum®, Force®, Admire®, Regent®, and Warrior® was estimated after application to sand and soil drenches for control of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), melon fly, Bactrocera cucurbitae (Coquillett), and oriental fruit fly, Bactrocera dorsalis (Hendel), in Hawaii. Susceptibility of each species differed based on LC50. In sand, the order of toxicity at LC50 for C. capitata from most toxic to least toxic was: diazinon>Force=Warrior>Admire=Platinum>Regent. The order of toxicity for B. dorsalis was: diazinon>Platinum=Warrior=Force>Regent=Admire. The order of toxicity for B. cucurbitae was: Warrior=diazinon>Force=Regent=Platinum=Admire. A susceptibility ratio for each of these insecticides compared to diazinon was made by dividing the acute LC90 of each insecticide by the LC90 of diazinon. Susceptibility ratios showed that Warrior was the most effective product compared to diazinon followed by Force. Laboratory studies in sand were followed by an evaluation of specific concentrations of Warrior and Force in field soils from two sites on the island of Kauai. Performance of both products was lower in soil compared to sand. Average concentrations that caused at least 95% mortality in soil in all three fruit species were 121 g ai/ha for Force and 363 g ai/ha for Warrior compared to 182 g ai/ha for diazinon. These results indicate that Force and Warrior could be used as soil treatments for control of tephritid fruit flies.