Toxicity of the powdery formulation of Hyptis spicigera (Lamiaceae), Azadirachta indica (Meliaceae) and Vepris heterophylla (Rutaceae) Single and in combination on Tribolium castaneum Herbst. (Coleoptera: Tenebrionidae)

Abstract

The red flour weevil, Tribolium castaneum (Herbst 1797) is a pervasive pest, polyphagous which is becoming increasingly resistant to the normal insecticides. Finding alternative insecticides to those because of their inefficiency pollute the environment and poison consumers is an emergency. An ethno-botanical survey conducted with about 300 farmers in the Far North region of Cameroon identified 15 local plants insecticides associated with food during storage in combination with two or three others. Among these plants, the most used are Hyptis spicigera (Lamiaceae) 78%, Azadirachta indica (Meliaceae) 76.6% and Vepris heterophylla (Rutaceae) 28,33% which is more used in mountain area. The powders of these single plants are insecticides on T. castaneum, however A. indica single or in combination with H. spicigera gives better insecticidal efficacy 73.33% and 66.67% mortality respectively.

Keywords: Tribolium castaneum, stocked food stuff, combination, vegetal powder, insecticide