摘要：Aedes aegypti L. (Diptera: Culicidae) is one of the most dangerous mosquito species in the world. This species transmits pathogens of many diseases that cause more than ten thousand human deaths to occur annually worldwide. For the control of Ae. ae-gypti, different types of insecticide groups are widely used but this mosquito developed resistance to many of these insecticides. Lichens are special organisms that include fungi with algae and/or cyanobacteria. They can produce various kinds of secondary metab-olites that have biological activities on different pests. Of these metabolites; atranorin and usnic acid are the most known and common metabolites ex-tracted from many lichen species. In this research, it was aimed to investigate the toxic effects of(-)-usnic acid and atranorin on larvae of Ae. aegypti. Aedes aegypti late second and early third instar larvae were used in toxicity assays. Stock solutions of atranorin and (-)-usnic acid were prepared by dissolving of metabolite in acetone. Ten larvae of Ae.aegypti were released to the test solution and the mortalities were recorded at 24 h intervals during 120 h and the per-centage mortality rates were obtained from the aver-age of four replicates. Lethal concentrations were calculated using probit analysis.According to re-sults, both metabolites caused high mortalities and the median lethal concentrations(LCso) of the atranorin and usnic acid were determined as 3.3 ppm and 3.8 ppm, respectively at 120 h. Atranorin, at 10 ppm concentration, caused 100% mortality while us-nic acid at 10 ppm concentration caused 61.3%. Li-chens produce many secondary metabolites and we suggested that these metabolites could be used for development of new mosquicidal agents.
