INSECTICIDE SUSCEPTIBILITY STUDIES OF Aedes aegypti (LINNAEUS) TO SYNTHETIC PYRETHROIDS CYPERMETHRIN AND BIFENTHRIN

摘要

Insecticide susceptibility studies were carried out in the laboratory maintained strains of Aedes aegypti, vector for Dengue and dengue hemorrhages, Chikungunya, yellow fever etc. A total of twenty strains were subjected by taking late third instar larvae for two organophosphate insecticides i.e., Cypermethrin and Bifenthrin by applying standard larval test procedure of world health organization (1981). The data showed that the lowest LC5() value of 0.00044 mg/1 was observed in two strains i.e., Gollarahatti (GUI) and Goravanahalli (GVH) whereas highest LC50 value of 0.00097 mg/1 was recorded in Maddur (MDR) Strain for Cypermethrin. Similarly, for Bifenthrin the lowest LC_(50) value of 0.000117 mg/1 was observed in Menakanahalli (MNH) strain and thehighest LC_(50) value of 0.001824 mg/1 was recorded in Karkala (KRK) strain.The resistance ratio of LC_(50) ranges between 1.00 - 2.20 and 1.00 - 15.59 for Cypermethrin and Bifenthrin respectively. The value of LC_(50), LC_(50) regression equation, correlation of coefficient, X~2 and resistance ratio of insecticides on each on of the strain were calculated and presented. The present study showed that Cypermethrin is more effective as larvicide to control Ae. aegypti when compared to Bifenthrin.