Antifeedant effect of neem, Azadirachta indica A. Juss., kernel extracts on Kraussaria angulifera (Krauss) (Orthoptera: Acrididae), a Sahelian grasshopper
Keywords:Azadirachta indica, Neem, Kraussaria angulifera, Sorghum, Niger, Pearl millet
AbstractThe neem tree, Azadirachta indica A. Juss., is now grown extensively throughout the Sahel. Neem kernel extract (NKE) appears to offer the possibility of being a readily available and easily prepared crop protectant for use by subsistence fanners. NKE was tested in Niger against the grasshopper, Kraussaria angulifera (Krauss), a univoltine species of economic importance on grain sorghum and pearl millet. In field cage experiments using sorghum seedlings, aqueous NKE, prepared on site, was as effective as a USDA-prepared ethanol extract of Indian origin. For 72 h post-treatment, the feeding injury sustained by neem-sprayed seedlings was not significantly different from that sustained by Cymbush/Cygon-sprayed seedlings. Neem appeared to be more effective against nymphs than against adults. In feeding-choice experiments with nymphs, neem-sprayed seedlings sustained significantly less feeding injury than did nonsprayed seedlings for 144 h post-treatment.