Larvicidal and Repellent Activities of Cestrum nocturnum (leaves) Extracts against the Mosquito Vector, Culex antennatus Becker (Diptera: Culicidae)

The present study investigated the larvicidal and repellent activities of Cestrum nocturnum (leaves) different extracts against Rift Valley Fever vector, Culex antennatus. The obtained results showed that the petroleum ether extract was the most effective extract against Cx. antennatus larvae followed by chloroform, acetone, and ethanolic extracts. The LC50 values of petroleum ether extract recorded 179.4, 164.2, and 148.7 ppm against Cx. antennatus third larval instar after 24, 48, and 72 h., respectively. On the other hand, at 6.67, 3.33, and 1.67 mg/cm2, ethanolic extract induced a degree of repellency equal to 93.1, 90.1, and 60.2% within the 4h post-treatment, respectively. Generally, petroleum ether extract proved high efficacy as repellents. At 3.33mg/cm2 petroleum ether extract produced the highest protection (100.0%) during the entire testing period of 4h post-treatment. Moreover, the protection (93.3, 90.7 and 80.8%) obtained at 2.67, 1.67 and 0.833 mg/cm2, respectively, compared with 100.0% repellency for DEET at a dose1.8 mg/cm2. So, Ce. nocturnum tested extracts can be considered as new promising controlling agents against the mosquito vector, Cx. antennatus.