Toxicity and Enzymatic-Changes Efficiency of Pistachio Peel and Basil Essential Oils against Plodia interpunctella (Hűbner) Larvae

ABSTRACT. Indian meal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), is one of the most important insect pests of storage products. Considering the adverse effects of chemical pesticides, it is necessory to find substitute agents for managing insect pests, including P. interpuntella. Plant-derived essential oils have been introduced as suitable candidates to replace detrimental synthetic chemicals. Therefore, along with the toxicities of the essential oils of pistachio peel and basil leaves, their effects on the α-amylase enzymes and protein contents of 5th instar larvae of P. interpuntella larvae were evaluated in the current study. Concentrations of the pistachio and basil essential oils were regarded to be 50-150 and 60-400 µl.l within 24 and 48 h exposure times, respectively. The results showed that the considered times and concentrations had significant effects on P. interpuntella larvae (P<0.01). The mortality rates increased by enhancing their concentrations. LC50 were 178.14 and 89.34 µl.l and 49.79 and 31.28 µl.l after 24 and 48 h, respectively. The essential oils demonstrating 30.8 and 37.8% of inhibitions for the relative α-amylase enzyme activities in the treated 5th instar larvae were significantly different from those of the control group. The essential oils of pistachio peel and basil displayed promising potentials for the management of P interpunctella with especial fumigant toxicities capable of disrupting the protein content and α-amylase inhibitory activity.