Initially found to be active as a feeding inhibitor towards the desert locust (Schistocerca gregaria), it is now known to affect over 200 species of insects, by acting mainly as an antifeedant and growth disruptor. It was recently found that azadirachtin possesses considerable toxicity towards African cotton leafworm (Spodoptera littoralis), which are resistant to a commonly used biological pesticide, Bacillus thuringiensis. Azadirachtin fulfills many of the criteria needed for a good insecticide. Azadirachtin is biodegradable (it degrades within 100 hours when exposed to light and water) and shows very low toxicity to mammals (the in rats is > 3,540 mg/kg making it practically non-toxic).
