Toxicity and repellence of African plants traditionally used for the protection of stored cowpea against Callosobruchus maculatus

In a search for botanical products to control the main insect pest of stored cowpea, Callosobruchus maculatus, 33 traditionally used African plants were tested in the laboratory for their toxic and repellent effects against this beetle. Toxicity was evaluated measuring life history parameters in a no-choice situation. Powders of Nicotiana tabacum, Tephrosia vogelii and Securidaca longepedunctdata significantly reduced the number of progeny. Repellence was evaluated by observing the behaviour of female beetles exposed to treated and untreated beans in a linear olfactometer. Clausena anisata, Dracaena arborea, T. vogelii, Momordica charantia and Blumea aurita were repellent to the beetle, whereas Chamaecrista nigricans, Azadirachta indica and Hyptis suaveolens were attractive. Our results indicate that botanical products may provide effective control of C. maculatus in cowpea. (C) 2003 Elsevier Ltd. All rights reserved.