Inhibitory effects of Punica granatum L. peels extract on antioxidant enzymes, reproductive and life history characters of cowpea weevil, Callosobruchus maculatus F.

Abstract

The cowpea beetle, Callosobruchus maculatus (F.) (Coleoptera: Bruchidae) is a common and extremely polyphagous pest of legumes and exploits various different stored grain legumes, including some of the most economically important stored grains. This work aimed to test the insecticidal effect of the peel extract of pomegranate by observing the survival, biochemical parameters (Superoxide dismutase (SOD.), Catalase (CAT.), glutathione s-transferase (GST) activity), and demographic characters of the Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) a pest of stored crops. Sub-lethal concentration (LC30) effects were evaluated on the susceptibility of stored cowpea grains in two generations of C. maculatus. The cowpea weevils were reared on cowpea to investigate the life table characteristics under 28 ± 2 ºC, 65 ± 5 %, and RH 16:8 h (L: D) conditions. The number of eggs laid and the number of emerging adults were determined at least in LC₃₀ concentration in both generations. Life table characteristics (r, GRR, R₀, λ, and T) were significantly reduced in LC₃₀ concentration_, especially in generation 2, compared with the control treatment. Exposure to pomegranate peel extract led to changes in antioxidant enzymes and increased CAT, SOD, and GST activities of cowpea weevil (females and males) in the first and second generations of the examined. These variations can result in survivorship and energy skill conduction during oviposition, likely mechanisms complex with herbal extract toxicity. This result can contribute to finding a new method to control stored pests such as cowpeas.