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In the present investigation, impact of sub lethal concentrations of entomopathogenic fungi, namely Isaria fumosorosea, Beauveria bassiana and Paecilomyces variotii, secondary metabolite on feeding, growth, fecundity and hatchability of Spodoptera litura was performed. The S. litura treated with I. fumosorosea and B. bassiana metabolites exhibited renounced food consumption. The growth rate of treated S. litura with metabolite of I. fumosorosea had drastic reduction. In the case of approximate digestibility (AD), maximum impact was established by the I. fumosorosea isolate, which significantly reduced the approximate digestibility of the IV and V instar larvae. The III instar larvae of S. litura treated with I. fumosorosea metabolite showed significantly lower efficiency of conversion of digested food (ECD) and efficiency of conversion of ingested food (ECI) values than IV and V instars. However the performance of metabolites on fecundity and hatchability of S. litura was immense. Therefore, metabolites of I. fumosorosea could be reliable biocontrol agent, which has been highly recommended for S. litura management in commercial crops.

A highly active silver nanoparticle (SmAgNps) was synthesized in the present study by using Sargassum muticum extract. The instrumentations such as scanning electron microscope (SEM), energy dispersive X-ray (EDAX), and X-ray diffraction (XRD) were used to reveal the nanoparticle morphology and size. The insecticidal activities of SmAgNps against Ergolis merione reveals prominent changes in the protein profile of hemolymph, morphology of hemocytes, and deteriorated midgut inclusions such as lumen, basement membrane, fat body, and gastric caeca. From this study, it was observed that phytochemicals of S. muticum was a prominent precursor for the synthesis of highly active nanoparticles.

The present study reveals the larvicidal activity of silver nanoparticles (AgNPs) synthesized by Bacillus thuringiensis (Bt) against Aedes aegypti responsible for the diseases of public health importance. The Bt-AgNPs were characterized by using UV-visible spectrophotometer followed by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy. A surface plasmon resonance spectrum of AgNps was obtained at 420 nm. The particle sizes were measured through SEM imaging ranging from 43.52 to 142.97 nm. The Bt-AgNPs has also given a characteristic peak at 3 keV in EDX image. Interestingly, the mortality rendered by Bt-AgNPs was comparatively high than that of the control against third-instar larvae of A. aegypti (LC50 0.10 ppm and LC90 0.39 ppm) in all the tested concentrations, viz. 0.03, 0.06, 0.09, 0.12, and 0.15 ppm. Hence, Bt-AgNPs would be significantly used as a potent mosquito larvicide against A. aegypti.