Perspectives de gestion biointensive des foreurs des tiges de sorgho en Afrique de l'Ouest

Studies were conducted from 1993–1995 at Samanko, Mali, on rearing and pheromone trapping of Busseolafusca Fuller (Lepidoptera: Noctuidae), and on the insecticidal effect of extracts of Jatropha curcas (Euphorbiaceae) on B. fusca and Sesamia calamistis Hampson (Lepidoptera: Noctuidae). A technique for mass rearingof B. fusca larvae on a chickpea and sorghum leaf-based meridic diet was developed, requiring about 10 g of diet per larva. An average of 7.3 successive generations were obtained per year. Pupal and larval mortalities were less than 15%. Oviposition was obtained on artificial substrates, with a fecundity of 300–500 eggs per female. Laboratory tests were conducted with diets in which extracts of nuts of J. curcas had been added. A100% larvicidal effect was obtained with B. fusca and S. calamistis at 0.01% and 1% crude oil concentration respectively, and with 0.025% of the phorbol ester fraction on S. calamistis. Trapping experiments using traps made of aluminum trays baited with synthetic pheromone showed that B. fusca male moths flights could be satisfactorily monitored. An improvement of traps and/or pheromone effectiveness is, however, necessary before their use as a control method.