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

The effects of neem seed kernel extracts from different solvents on the predacious mite Phytoseiulus persimilis Athias-Henriot and the phytophagous mite Tetranychus cinnabarinus (Boisd.) were compared. All extracts were much more toxic to the latter pest than to the former. Using the respective LC50 for the two species, the toxicity index (LC50Phytoseiulus/LC50Tetranychus) was found to be 3 for the methanol, 4 for the ethanol, 23 for the acetone, and 58 for the pentane extract. The order of toxicity of the extracts (pentane > acetone > ethanol > methanol) was valid only for T. cinnabarinus. The EC50s for reduction of fecundity were rather close for the two species. © 1987, Springer Science + Business Media B.V.. All rights reserved.