Insecticide susceptibility studies in populations of Aedes aegypti from Maharashtra State, India
Kaul, H.N.; Dhanda, V.; Deobhankar, R.B.; Mahadev, P.V.
Indian Journal of Medical Research 64(12): 1760-1768
1976
ISSN/ISBN: 0019-5340 PMID: 1024076 Document Number: 107941
Evaluation of insecticide susceptibility was conducted on adult populations of A. aegypti from 10 localities in 7 districts of Maharashtra State, in addition to a VRC [Virus Research Centre] colony strain, using a WHO technique and kit. Of the 11 strains tested against DDT, 6 were resistant and 5 were intermediate. None of the strains was completely susceptible. The strains from Kamptee, Barsi and Kolhapur were highly resistant, the LC50 being > 4.0%. The resistance to DDT may be attributed to the extensive use of this insecticide for malaria control in the country. Barsi strain which showed high resistance to DDT, was intermediate/tolerant to BHC and malathion, but susceptible to dieldrin. The resistance to BHC may be as a result of intermittent focal BHC spraying in this region since 1963. However, its tolerance to malathion is difficult to explain. Although development of resistance in A. aegypti to certain organophosphorus compounds has been demonstrated in the laboratory, real resistance to organophosphorus compounds is at present unknown. Thus, the malathion-tolerant field population of A. aegypti from Barsi appears to be an isolated observation in India.