Larvicidal activity of oak <Emphasis Type="Italic">Quercus infectoria</Emphasis> Oliv. (Fagaceae) gall extracts against <Emphasis Type="Italic">Anopheles stephensi</Emphasis> Liston

There is a growing interest in the use of botanical insecticides to reduce the use of synthetic pesticides in order to avoid environmental side effects. Anopheles stephensi is the primary vector of urban malaria, an endemic disease in India. So, an effort to assay An. stephensi larvae with gall extracts of Quercus infectoria was made under laboratory conditions at Mysore. Ethyl-acetate extract was found to be the most effective of all the five extracts tested for larvicidal activity against the fourth instar larvae, with LC₅₀ of 116.92 ppm followed by gallotannin, n-butanol, acetone, and methanol with LC₅₀ values of 124.62, 174.76, 299.26, and 364.61 ppm, respectively. The efficacy in killing mosquito larvae may make this plant promising for the development of new botanical larvicide.