In addition, both Bioact-T35 and Cyperrnethrin have some repellency effect on P. xylostella larvae. Comparing the effect of contact toxicity and stomach poison toxicity, Bioact-T35 possesses higher contact insecticidal activity than stomach poison insecticidal activity against the larvae of P. xylostella. This result may be caused by its strong antifeedant properties. A large amount of the toxicant is required to be present before a small amount finds entrance into the body. In summary, Bioact-T35 possesses four model of actions, namely contact toxicity, stomach poison, antifeedant activities and repellency effect.
Antifeedant activity is the strongest one, followed by contact toxicity.
The strong antifeedant combination with repellency effect lead to the weak stomach poison toxicity. Neem as an antifeedant for certain phytophagous insects and a bruchid on pulses. I st Int. North American ethnobotanicals as sources of novel plantbased insecticides. The chemical participants.