Toxicity, antifeedant and repellent effect of Azadirachta indica (A. Juss) and Jatropha carcus L. aqueous extracts against Plutella xylostella (Lepidoptera: Plutellidae)

Toxic effects and antifeedant rate of aqueous extract based on Azadirachta indica (A. Juss) and a Jatropha carcus L. seeds and leaves and two insecticides commonly used in vegetable fields on the larvae of the diamondback moth, Plutella xylostella L. were studied by bioassay using no-choice tests. The repellent effect of these products was evaluated by bioassay using choice tests. Aqueous extract of neem and jatropha seeds 80 g/L have higher toxic effect, antifeedant rate and repellent effect on Plutella xylostella larvae than the insecticides Decis and Cypercal in 72 hours. Antifeedant rate of aqueous neem seeds 80 g/L, aqueous jatropha seeds 80 g/L extracts and insecticides Decis 12 EC and Cypercal 50 EC were 98.99%, 97.53%, 78%, 91.30%, respectively. Antifeedant activity was increased with increasing plant extract concentrations. Aqueous neem and jatropha seeds 80 g/L were on repellent class II and insecticides Decis and Cypercal were on repellent class I. Based on the results of this study aqueous extract of neem and of jatropha seeds 80 g/L could be used to protect crops against Plutella xylostella . KEYS WORDS: Azadirachta indica ; Jatropha carcus ; Plutella xylostella ; biopesticides ; larvae mortality