Antifeedant and larvicidal activity of bioactive compounds isolated from entomopathogenic fungi Penicillium sp. for the control of agricultural and medically important insect pest (Spodoptera litura and Culex quinquefasciatus)

Abstract

The use of chemical insecticides in agriculture has posed several challenges to environment and ecosystem health. Pesticides of biological origin are considered to be suitable for sustainable environment. In the present study bioactive compounds from Penicillium sp. was isolated and tested for insecticidal activity on Spodoptera litura and Culex quinquefasciatus larvae. Ethyl acetate extract of Penicillium sp. were characterized using GC–MS and FT-IR analysis. GC–MS analysis showed 20 different bioactive compounds namely, Propanoic acid, ethyl ester, Acetic Acid, Propyl Ester, Isopentyl Acetate, Acetic Acid, 2-Methylpropyl Ester, Behenic alcohol, 1-Hexadecene, 1-Octadecene, 1-Hexacosanol, n-Hexadecanoic acid, 1-Tetradecanol, 1-Dodecene, Tetrydamine, and Octadecanoic acid. The presence of functional groups such as, chloroalkanes, sulfonates, phosphines, amines, carboxylic acid, alkanes, and isocyanates was identified by using FTIR. Ethyl acetate extract of Penicillium sp., were tested for larvicidal activity on Spodoptera litura and Culex quinquefasciatus larvae showed significant larval mortality after 48 h of exposure with LC50: 72.205 mg/ml: LC90: 282.783 mg/ml and LC50: 94.701 mg/ml: LC90:475.049 mg/ml respectively. High antifeedant activity was observed in 300 μg/ml at 48 h of crude extract exposure. The present study concludes that Penicillium sp., secondary metabolites are effective for control of Spodoptera litura and Culex quinquefasciatus larvae.