Abstract :
The activity of methanol, chloroform and petroleum ether extracts of Prunus domestica and Rhamnus cathartica leaves against third-instar larvae of the filarial vector, Culex pipiens (Diptera: Culicidae) and resulted pupae were evaluated. In addition, the repellent activity of tested extracts against C. pipiens starved females was determined. Results showed that all tested extracts possess larvicidal activity against C. pipiens third larval instar; however, the petroleum ether extract from leaves of P. domestica and R. cathartica was more effective (LC50 33.3 and 63.4ppm) than chloroform (LC50 70.8 and 192.1ppm) and methanolic extracts (LC50 132.7 and 273.5ppm), respectively. Also, both larval and pupal periods were prolonged by all tested extracts as compared with control groups. On the other hand, all tested extracts exhibited a variable degree of repellency against C. pipiens starved females depending on dose and solvent used in extraction. The highest repellency (97.3 and 90.2%) was recorded by petroleum ether extract of P. domestica at the highest doses (3.33 and 5.0mg/cm2), while petroleum ether extract of R. cathartica recorded 89.8 and 80.0% repellency at the same doses, respectively. These results proved that methanol, chloroform and petroleum ether extracts of P. domestica and R. cathartica leaves act as C. pipiens control agents, even in the crude form, providing an opportunity to reach ,mosquito control agents from cheap, available plants which are safe to non-target organisms, as well as environment.
Keyword :
Larvicidal; repellent; Culex pipiens; Prunus domestica; Rhamnus cathartica