Mansour, F.A., Dept. of Entomology, ARO, Newe Ya’ar Regional Experiment Station, P.O. Haifa, Bet Dagan, Israel
Ascher, K.R.S., Dept. of Toxicology, ARO, Volcani Center, Bet Dagan, Israel

Extracts of neem (Azadirachta indica A. Juss) seed kernels prepared from various solvents affected the behavior and fecundity of the carmine spider mite, Tetranychus cinnabarinus (Boisd.). Bean leaf discs freshly sprayed with different concentrations of the extracts strongly repelled the females from the treated leaves and egg-laying was reduced. On the basis of EC 50s for both parameters, the order of effectiveness of the extracts was pentane > chloroform > n-butanol > acetone > methanol > H2 0 (inactive). The activity decreased with increasing dielectric constant of the extracting solvent. The chloroform and butanol extracts in the original solvents were phytotoxic. Bean leaf discs 7 days after spraying with the pentane and acetone extracts, still caused mortality and reduction in fecundity of adult females, but no repellency. The acetone and the pentane extracts sprayed directly on adult female mites on bean leaf discs, caused repellency and reduction of fecundity and also mortality of adults. © 1983, Springer Science + Business Media B.V.. All rights reserved.