Evaluation of crude chitinases extracted from marine biomass (stomach of fishes) on the feed insect: Callosobruchus maculatus (Coléoptera: Bruchidae)

Abstract

In order to develop a marine waste insecticide to protect our environment, this study aims to assess the potential of crude chitinases (specific enzymes hydrolysis of chitin) extracted from marine biomass as a biological insecticide at different doses 3, 12 and 21%, on the larva feed of the insect, a destroyer of stored products. The unexpected results show that the amount of food ingested in the control batches (3.7 g) is higher than in treated ones by these crude chitinases (3.02 g),(0.9 g) and (0.34 g) respectively. The dose of 21% produced a very significant larvicidal activity (97.12%) by adults rate emerging at only (2.88%) compared to the reference sample (100%). Histological sections of the digestive tube of treated larva at the same dose (21%) show a destruction of different cell types after the death of larva. This feed inhibition is explained by the effect of the extract crude chitinases on peritrophic membrane of the stomach of this bio aggressor (incorporated mainly of chitin), that prevents it to reach the adult stage.