Efficacy of aromatic and medicinal plant powders against callosobruchus maculatus f. (chrysomelidae: Bruchinae)

Abstract

The cowpea bruchid Callossobruchus maculatus Fab. (Coleoptera: Chrysomelidae: Bruchinae) is the major pest of chickpea in storage. Thus, the present study aimed to evaluate the insecticidal properties of powders of 8 Moroccan aromatic plants on biological parameters of C. maculatus. The toxicity of the powders was assessed by measuring the parameters of the life cycle in a situation of non-choice under laboratory conditions (25 ± 1°C, 70–75% HR and a photoperiod of 14h (light) / 10h (darkness). The powder of Mentha pulegium has completely wiped out the population of the Callosobruchus maculatus (% IR=100%) 2%, 1% and 0.5% W/w. Similarly, Mentha pulegium powder retained seed weights, which remained significantly different (P < 0.01) from the control weight. Also, Origanum compactum, Mentha rotundifolia and Inula viscosa have significantly reduced (P < 0.01) the population of bruchids, the percentage reduction reached (% IR= 97.5, % IR = 89.32, and % IR = 27, 38% by the highest 2%). The other plants show no significant difference from the control. The results therefore suggest that Mentha pulegium powder has an insecticide potential similar to those of conventional insecticides and could be an alternative method against infestations and damage caused by C. maculatus in stored products.