larvicidial effects of essential oil and methanol extract of achillea wilhelmsii c. koch (asteraceae) against anopheles stephensi liston (diptera: culicidae), a malaria vector

Background: mosquitoes are responsible for the background: mosquitoes are responsible for the transmission of many pathogens and parasites and consequently serious diseases in humans. currently, application of plant derivatives has been suggested as an alternative bio-control technique for these medically important vectors. methods: in this study the essential oil and methanol extract of achillea wilhelmsii were tested against late-3rd or young-4th instar larvae stages of mosquito vector, anopheles stephensi, under laboratory condition. the larval mortality was calculated after 24 h of the exposure period. data were subjected to probit analysis in order to estimate the lethal concentration for 50% and 90% of mortality values. results: results showed that the essential oil induced 100% larval mortality of an. stephensi larvae after 24 h with a dosage of 160 ppm, however, a dosage of 320 ppm of methanol extract was required to reach 100% larval mortality.the essential oil methanol extract exerted significant larvicidal activity with lc50 values of 39.04 and 115.73 ppm, respectively. conclusion: our finding suggests that a. wilhelmsii oil is a potential source and has valuable larvicidal compounds for mosquito larval control.