Research Article
Khalid A. Asiry
Abstract
This study was conducted as a pilot study to evaluate the toxicity of three different extracts (water, ethanol and acetone) from Fattaka fruits, Pergularia tomentosa L. (Asclepiadaceae), at five different concentrations against the fourth instar larvae of the Dengue Fever mosquito vector Aedes aegypti (Diptera: Culicidae). Results showed that the ethanolic extract caused a higher mortality of A. aegypti larvae compared with other solvents. In the ethanolic extract treatment, the percentage mortalities of the A. aegypti larvae ranged between 16.25% at the lowest concentration and 97.5% at the highest concentration after 24 hours. Also, toxicological parameters including LC50 and LC95, toxicological index and Slope of the log-dose-probit lines showed that the ethanolic extract of this plant was more effective for controlling A. aegypti, showing LC50 of 0.06 ppm and LC95 of 2.37 ppm. This was not greatly different at 48 hours in which the mortalities of A. aegypti ranged between 32.5% and 98.75%, and the LC50 was 0.025 ppm and the LC95 was 1.668 ppm. Overall, this study suggests that more studies on the chemistry of P. tomentosa and its bioassays are required before confirming its use to biocontrol mosquitoes.