A report on the susceptibility status of Anopheles minimus (Theobald) against DDT and deltamethrin in three districts of Assam.

Laboratory bioassays were carried out to study the susceptibility status of Anopheles minimus the major vector of malaria in three districts of Assam—Sonitpur, Darrang and Kamrup against the commonly used insecticide DDT (for indoor residual spray) and deltamethrin used for treating the bednets. WHO standard technique was followed for the test using insecticide impregnated papers supplied by them. It was revealed in the study that the species is still susceptible to DDT (4% x 1 hour) as 97.5, 98.3 and 96.3% mortality was observed in the tests carried out with mosquitoes collected from the field of Districts Sonitpur, Darrang and Kamrup respectively. Against deltamethrin (0.05% x 1 hour) 100% mortality was observed in An. minimus in all the three districts.