comparative study on susceptibility of the larvae of two wild strains of amopheles stephensi to eight insecticides, in south of Iran

Susceptibility of two wild strains of An. stepliens, collected from Kazeroun [ST-K.Az and Bandar-Abbas [ST-BAN], south of Iran was compared to fenthion, malathion, temephos, pirimiphos, methyk, deltamethrth, DDT dimilin and etopenprox as larvicides in the laboratory. Susceptibility test on the ST-KAZ strain indicated that this strain is susceptible to the named insecticides i.e. the resistance ratios remained between 0.91 to 1.37 folds that of the ST-TEH strain, the susceptible laboratory stock.The ST-BAN strain has the long history of insecticide - application like, DDT, dieldrin, malathion, propoxur, actellic lambdacyhalotith[icon] as adulicides and abate as a larvicide, therefor it showed different pattern of susceptibility to the latter insecticides. The ST-BAN strain showed susceptibility to DDT, deltamethrjn, etofenprox and dimilin, moderately tolerant to fenthion and temephos [i.e.reslstance ratios ranged between 1.67 to 1.75 folds] and tolerant to Pirimiphos-methyl and malathion with resistance ratio of about 2.37 folds, that of the ST-TEH strain. The observer's tolerance in the ST-DAN strain to Pmmiphos-methyl [actellic] and malathion might be as the result of regular use of adulticides or abate in malaria control programs in south of Iran and develop of cross-tolerance in An.stephensj from Bandar-Abbas south of Iran

Residual effect of etofenprox [trebon 20 % WP] as a new insecticide on different surfaces in south of Iran

The residual activity and air-borne efficacy of Etofenprox [trebon 20% WP] were studied on different surfaces in hut scale trial, in Kazeroun south of Iran, in 1992. The bio-assay contact mortality tests with trebon against Anopheles stephensi showed similar responses on pluster, cement and mud surfaces [except wooden surfaces], i.e. at 250, 400 and 500 mg/m2, trebon had residual activity for about 75 to 82, 95 and 110 days respectively. On wooden surfaces, trebon showed longer residual activity than the latter surfaces, i.e. at 250, 400 and 500 a.i. mg/m2, trebon had residual activity for 90, 110 and 127 days respectively. Fumigation test with trebon at different rates of application showed no remarkable effect on An.stephensi. Based on the results of this study, trebon at 500, 400 and 250 mg/m2 had a residual activity for about 4, 3 and 2.5 months on different surfaces and hence the recommended dosages for continuation study could be 500 and 250 mg/m2 in a large scale trial in south of Iran