DDT-susceptibility status of malaria vector Anopheles balabacensis balabacensis Baisas (Diptera : Culicidae) in Bangladesh.

DDT-susceptibility tests on Anopheles balabacensis balabacensis Baisas carried out during several years especially during 1979 and 1980 in Sylhet district have been reported. The LC50 value for 1980 was found to be 0.88 +/- S.E. 0.02 showing 2.38 fold increase of tolerance from 1970 (LC50 = 0.37 +/- S.E. 0.07). The species is still found to be susceptible to DDT in Bangladesh. The implication of the use of DDT in controlling malaria due to this species is also discussed.