Azadirachtin Efficacy in Colorado Potato Beetle and Western Flower Thrips Control

Abstract

Colorado potato beetle (CPB) and western flower thrips (WFT) are agricultural pests which are difficult to control due to resistance developed to many classes of insecticides. A botanical insecticide azadirachtin could represent an ecologically acceptable alternative for their management. This research tested the efficacy of azadirachtin on CPB and WFT mortality and feeding intensity, as well as thrips oviposition. Azadirachtin was used in three doses in laboratory trials. The results showed that this botanical insecticide was effective on larval stages of CPB and reduced the damages on treated leaves, but did not cause significant mortality or reduction in feeding intensity of the adults. It was not sufficiently effective against the WFT adults either, but it reduced the feeding damage on leaves and prevented egg laying. The results indicated that, even though azadirachtin did not have a significant adverse effect on the adult CPB and WFT insects, it reduced the overall population by affecting the CPB larvae or feeding intensity and egg laying in WFT. Antifeedant and anti-ovipositional activities, as shown in the case of WFT, should also be considered when assessing azadirachtin efficacy on insect pests.