Insecticidal effects of a novel polyherbal formulation (HF7) against Culex pipiens L. (Diptera: Culicidae)

Journal Article

2022

Published in: https://doi.org/10.1016/j.sjbs.2021.08.101

Plant secondary metabolites represent the most efficient and convenient method to control and overcome environmental pollution and insecticidal resistance. This study explored the mosquitocidal activity of the combined extract of seven plants, (HF7) extracted using a Soxhlet extractor against Culex pipiens under laboratory conditions. Exposure of the 3rd instars of Cx. pipiens to HF7 hexane extract resulted in LC50:114.5 μg/mL and LC90:117.0 μg/mL values after 24 h. The ovicidal activities of hexane extract against Cx. pipiens eggs were 21.6%, 48.3%, and 71.6% at 187.5, 93.7, and 46.88 μg/mL, respectively. HF7-treated larvae showed the formation of irregular blebbing of epithelial cells toward the lumen and sloughing into the gut lumen. HF7 extract resulted in 100% adulticidal mortality at the concentration of 3.7 mg/test tube  IC50 of HF7 extract was 97.03 μg/ml against larvae, at which nuclear and morphological
changes were observed. The spectroscopy spectrum of HF7 hexane extract disclosed the
presence of 57 different secondary metabolites, among which the dominant compound was
eugenol (32.3%). HF7 hexane extract could serve as a botanical insecticide for controlling
Cx. pipiens and potentially other mosquito species.after 30 min of exposure. The

• Magazine \ Newspaper: Saudi Journal of Biological Sciences
• Pages: Available online