Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/29/2003
Publication Date: 4/1/2004
Citation: Showler, A., Greenberg, S.M., Arnason, J.T. 2004. Deterrent effects of four neem-based formulations on gravid female boll weevil (Coleoptera: Curculionidae) feeding and oviposition on cotton squares. Journal of Economic Entomology. 97(2):414-421. Interpretive Summary: Three commercial neem-based insecticides and a neem seed extract containing 223 - 16,506 micrograms per milliliter azadirachtin were assessed for deterrence against egg laying and feeding by gravid female boll weevils in the laboratory. Deterrence was observed, but it was limited to less than 48 hours. Azadirachtin is apparently not the only, or the most influential, component of neem because deterrence was not associated with azadirachtin content.
Technical Abstract: Three commercial neem-based insecticides, Agroneem, Ecozin, and Neemix, and a neem seed extract, bitters, containing 1,036, 16,506, 471, and 223 g/ml azadirachtin, respectively, were assessed for feeding and oviposition deterrence against gravid female boll weevils, Anthonomus grandis grandis Boheman, in the laboratory. In choice and no-choice assays, each formulation repelled the weevils for 90 min. After 24 h in the choice assays, feeding punctures on squares treated with Agroneem, Ecozin, or bitters were fewer (P 0.05) than on controls, and oviposition on the Ecozin and bitters treated squares were fewer (P 0.05). None of the formulations were effective against feeding or oviposition in a no-choice assay after 24 h. Aging the formulations on square in outdoor conditions for 24 h before weevils were exposed to them resulted in significant reductions in feeding and oviposition (P 0.05). Feeding deterrence was observed in the Agroneem and bitters treatments (P 0.05), but no deterrence was detected after 72 h. Azadirachtin is apparently not the only, or the most influential, component of neem because deterrence was not correlated with azadirachtin content.