larvicical activity of bacillus thuringiensis h-14 (teknar) on mosquito larvae in ricefields, southern iran

an investigation was conducted to study the larvicidal activity of teknar (san-402-i-bacillus thuringiensis, serotype h-14, sandoz, 600 itu/mg) on mosquitolarvaein kazeroun, fars province, southern iran. five experimental plots were selected randomly in a rice field and three concentrations of teknar: .0003, .0006 and .0012 cc/1 was used. maximum larval mortality usually occurred during the first 24 hours of exposure. culicinae larvae were more susceptible than the anophelines. also, the first and second instars showed greater mortality than the third and fourth instars. the percent larval vortality were 71.8 to 81.5 in anophelines and 82.1 to 100 in culicinae at.0003 cc/1, 89.4 to 100 in anophelinae and 97.2 to 100 in culicinae at.0006 cc/1and 98.4 to 98.6 in anophelinae and 100 in culicinae at.0012 cc/1 concentrations respectively. no mortality was detected in the control plots. it was concluded that.0006 and .0003 cc/1 were the concentrations of choice for the proper mosquito larval control in the area.