Efficacy of oils and powders of some medicinal plants in biological control of the pea weevil (Callosobruchus chinensis L.)

Each year, the chickpea suffer’s from significant losses in both quantity and quality. These losses are observed particularly in stocks, which are principally due to attacks by weevils. The most devastating is the Chinese weevil (Callosobruchus chinensis). In the context of biological control as an alternative to chemical control, three plants were tested for their possible role organic insecticide, namely Thymus vulgarus, Santolina chamaecyparissus and Anagyris foetida. The leaf powders and oils of these plants that was extracted by hydro distillation were tested for their effect on the biology of C. chinensis such as fertility, longevity and sex ratio. The results showed that oils and powders of three different plants tested possess insecticidal activity against C. chinensis. By comparing these oils, thyme oil at a dose of 10 _l exhibited great biocidal power against insects as we experienced 100% mortality after only hours of exposure to treatment, hard tan l ʹoil santolina also had 100% mortality but at a dose of 20 _l. Regarding the powder, that of Santoline when compared to other powders at a dose of 1 g significantly reduces longevity (2.9 days), fecundity (3.06) and fertility (3.33). It even has an ovicidal effect. For 10 repetitions, we have recorded a single outbreak. This allows us to move forward so that the oils and powders tested plants can be used as bio insecticide for control of C. chinensis populations of pests of stored foodstuffs.