Bioassay of Artemisia annua leaf extracts and artemisinin against larvae of Culex quinquefasciatus and Culex tritaeniorhynchus.

Using in vitro bioassays, we evaluated the crude methanol, ethanol, chloroform, and acetone leaf extracts of Artemisia annua as well as pure artemisinin against late 3rd and early 4th instars of Culex quinquefasciatus and Cx. tritaeniorhynchus. Based on the lethal concentration for 50% mortality (LC50) and lethal concentration for 90% mortality (LC90) values, the chloroform leaf extract was the most toxic, followed by methanol, ethanol, and acetone. The LC50 and LC90 values for chloroform extract were 0.18 and 9.65 ppm against Cx. quinquefasciatus and 0.91 and 8.73 ppm against Cx. tritaeniorhynchus, respectively. The LC50 and LC90 values for artemisinin, dissolved in chloroform, were significantly higher, 14.31 and 296.39 ppm for Cx. quinquefasciatus and 4.13 and 50.36 ppm for Cx. tritaeniorhynchus, respectively.