CARBOXYL ESTERASE AND GST LEVELS OF CULEX QUINQUEFASCIATUS SAY AND AEDES AEGYPTI L. COLLECTED FROM THE SELECTED SITES OF MALAPPURAM DISTRICT

Abstract

Mosquitoes are the dreadful insects which transmits bacterial, viral and parasitic diseases including Malaria, Filariasis, Yellow fever, Chikunguniya, Dengue fever, Japanese encephalitis, Zika, West Nile fever etc. A careful and prolonged control of the vector can help to eliminate these diseases, but it is not an easy task due to its natural tolerance and development of resistance to available insecticides. The early detection of resistance in vector mosquitoes will help the local government to plan and select appropriate alternative control measures or insecticides for effective control. Quantitative metabolic enzymes assay have been commonly used in the detection of insecticide resistance because it is very sensitive and gives results rapidly even at low frequencies. In the present study, Carboxylesterase and Glutathione S-transferase (GST) activity in Culex quinquefasciatus Say and Aedes aegypti L of the selected sites from Malappuram District were studied. Enzyme activities were analysed to estimate the detoxification status of these mosquito species. There is a significant difference in carboxylesterase and GST activities in laboratory and filed populations. Cx. quinquefasciatus and Ae. aegypti of Ponnani area shows higher enzyme activity when compared to Tirur and Calicut University. Regular spraying of insecticides occurs in Ponnani and Tirur, but there is no insecticide application in Calicut University. The results reinforce the need for constant surveillance of mosquito populations susceptibility against the insecticides used in control programs as well as their effectiveness in the field.