Document Type : Original Article
Authors
1 Department of Entomology and Plant Pathology university of Tehran
2 Department of Entomology and Plant Pathology , College of Aburaihan, University of Tehran
Abstract
Extracts obtained from plants, which are mainly extracted from natural sources and different parts of plants, have been considered as a natural and efficient alternative to replace chemical pesticides. In this study, Eucalyptus camaldolensis and Thyme vulgaris plants were selected as plant sources to extract active and effective compounds from them by using an aqueous solvent. The purpose of this extraction was to investigate the effect of different concentrations of aqueous extract formulation on the mortality rate of 3rd instar larvae of the cotton bollworm (Helicoverpa armigera) in a laboratory environment. The results of this study showed that the use of different concentrations of aqueous extracts of eucalyptus and thyme produced statistically significant differences in the mortality rate of 3rd instar cotton bollworm larvae within 24 hours (p≤0.05). In the study of the lethality of the concentrations of 60%, 70%, 80% and 90% of aqueous extracts of eucalyptus and thyme, the results indicated that the concentrations of 80% and 90% caused the greatest losses to the 3rd larval instar of cotton bollworm H. armigera after 24 They created hours, which were equal to 25.00% and 25.00% for eucalyptus aqueous extract, respectively. While the concentration of 60% and 70% caused the lowest losses (20.00%), and for thyme aqueous extract it was equal to 25.00% and 25.00%, respectively, and the concentration of 60% and 70% caused the lowest losses (20.00%). As a result, aqueous extract formulations of eucalyptus and thyme showed similar toxic effects on cotton bollworm pest.
Keywords
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