Insecticidal activity of the powder from Capsicum frutescens (Solanaceae), Lavandula stoechas (Lamiaceae) and Syzygium aromaticum (Myrtaceae) against Callosobruchus maculatus insect pest of chickpea seeds

During storage, the seeds of legumes suffer considerable losses from several pests, mainly Callosobruchus maculatus. In Morocco, synthetic pesticides remain the most used means for the protection of stored products. They cause harmful effects on humans and the environment, in addition to resistance phenomena in pests. In perspective to develop a new approach to protect legumes against Callosobruchus maculatus, the powder of three plants (Capsicum frutescens, Lavandula stoechas Syzygium aromaticum) applied to the laboratory under controlled conditions (25 ° C, 70 ± 5% relative humidity and 10h light) were tested against Callosobruchus maculatus at the expense of chickpea seeds at 0.1; 0.5 and 1g. For each dose, 10 pairs of the weevil were released on 10g of treated seeds. In the same conditions, lots of untreated seeds were used as witnesses. Daily mortality of weevil, eggs, laid, hatched and unhatched emitted on seeds, emerged adults were identified. The analysis of plant toxicity tests reveals that the powders of (lavender, hot pepper and cloves) exert a variable insecticidal action on the various parameters of Callosobruchus maculatus, and that the powder of cloves has the highest lethal effect on adults weevil Callosobruchus maculatus at the same time as a maximal inhibitory effect on reproduction of the insect studied. It emerges from the various tests carried out that the plants used constitute a means of biological control which could substitute for the use of synthetic pesticides in order to protect stored products against pests, while preserving the environment as well as the quality of the stored commodity.