Bioactivities Of The Leaf Extract Of Citrullus Colocynthis Schrad And
Cucurbita Maxima Duchesne(Cucurbitaceae) Against The Mosquito
Anopheles Stephensi Liston(Diptera:Culicidae)
 

K.Mullai, A.Jebanesan^*, T.Pushpanathan
Division of Vector Biology, Department of Zoology, Annamalai University,
Annamalai Nagar-608 002, Tamilnadu, (INDIA)

The efficacy of the Cucurbitaceous plants against the clinically important mosquito species (Malarial Vector) Anopheles stephensi was assessed. The leaf extract of Citrullus colocynthis and Cucurbita maxima with four different solvents viz, benzene, petroleum ether, ethyl acetate and methanol were tested for larvicidal, ovicidal and repellent activities against An.stephensi. The larval mortality was observed after 24h exposure. The LC₅₀ values of C. colocynthis were 48.99, 58.62, 37.02 and 110.64ppm and the C.maxima exerted the LC₅₀ values of 92.81, 119.28, 67.41 and 163.23ppm respectively. The mean percent hatchability of the egg of An. stephensi were observed after 48h. 100% mortality was exerted at 375 ppm for C.colocynthis and at 500 ppm for C.maxima. Skin repellent test at 1.0, 2.5 and 5.0mg/cm² concentration of C.colocynthis gave the mean complete protection time ranged from 120.33 to 273.16 minutes and the C. maxima gave 94.66 to 226.66 minutes with the four different extracts.