Bioefficacy of (L.) -Hexane Extracts and Their Major Metabolites against the Lepidopteran Pests (fab.) and Dengue Mosquito (Linn.).

The present research investigated the chemical characterization and insecticidal activity of -Hexane extracts of (NH-EDx) along with their chief derivatives -Hexadecanoic acid (-HDa) and -Octadecanoic acid (-ODa) against the dengue vector and lepidopteran pest . Chemical screening of NH-EDx through GC-MS analysis delivered nine major derivatives, and the maximum peak area percentage was observed in -Hexadecanoic acid (14.63%) followed by -Octadecadienoic acid (6.73%). The larvicidal activity of NH-EDx (1000 ppm), -HDa (5 ppm), and -ODa (5 ppm) against the and larvae showed significant mortality rate in a dose-dependent way across all the instars. The larvicidal activity was profound in the as compared to the across all the larval instars. The sublethal dosages of NH-EDx (500 ppm), -HDa (2.5 ppm), and -ODa (2.5 ppm) also showed alterations in the larval/pupal durations and adult longevity in both the insect pests. The enzyme activity revealed that the α- and β-carboxylesterase levels were decreased significantly in both the insect pests, whereas the levels of GST and CYP450 uplifted in a dose-dependent manner of NH-EDx, -HDa, and -ODa. Correspondingly, midgut tissues such as the epithelial layer (EL), gut lumen (GL), peritrophic matrix (Pm), and brush border membrane (BBM) were significantly altered in their morphology across both and against the NH-EDx and their bioactive metabolites. NH-EDx and their bioactive metabolites -HDa and -ODa showed significant larvicidal, growth retardant, enzyme inhibition, and midgut toxicity effects against two crucial agriculturally and medically challenging insect pest of ecological importance.