Evaluation of the crude chitinases toxicity on the reproductive system of Callosobruchus maculatus (Coleoptera: Bruchidae)

Abstract

Insecticides represent the most used control method against the insect pests of stored food products. But there are strains of insects which are resistant to these insecticides: it is the case of the beetle of the chickpea Callosobruchus maculatus. The present study has for objective the evaluation of the biological activity of chitinolytic enzymes extracted from the fish offals Scorpaena scrofa (scorpion fish) on this beetle at different doses (3%, 6%, 9%, 12%, 15% and 21%) prepared with the buffer solution. The results obtained from three treatments (T1, T2 and T3) realized according to the dose of the crude enzyme and the time of exposure were compared with those of the controls and have showed a very significant efficiency of our crude enzyme on the reduction of the fertility rate of 100% by treating the couple (T1) at the same time as to treat the male (T3) and the female (T2) separately with the strongest dose (21%) for 48 h of exposure. It would be thus desirable to demonstrate the activity of these enzymes in the real conditions of storage.