Practical Implications of Insecticide Resistance in Culicine Mosquitoes

The control/eradication of culicines is receivi-ng increasag attention, since these mosquitoes are not only carriers of important diseases, such as filariasis, yellow fever, haemorrhagic fever, but have also been incrimtnated as important carriers of other arbo viruses of man and‘animals. F’urthermore, these mosquitoes are a great nuisance since they feed on man with great avidity. Control of .culicine mosquitoes is presenting. a problem since the common species are ubiquitous with high reproductive potential. With increasing urbanizalion general sanitation is lagging behind in most of the developing countries, with the result that some of the culicine species, especially the Culexpipiens complex, are breeding in large numbers. The current methods for control of these -species are based largely on the use of insecticides. The adult mosquitoes, particularly in the Culex pipiens complex, are naturally refractory to chlorinated hydrocarbon insecticides and develop resistance fairly rapidly to these compounds; in addition, recent reports indicate that the species are developing resistance to other groups of insecticides, such as organophosphorus compounds. Larvicides cari be used in certain situations, but there are increasing cases of resistance to insecticides even in the larval stage. The present status of resistance in culicine mosquitoes is briefly summarized as follows :