Agriculture and Vector Resistance

Abstract

Agricultural treatments mainly against cotton and rice pests put larvae and sometimes adults of several vector species under considerable selection pressure for insecticide resistance. Resistance to compounds which had never been used for public health, but were employed in agriculture, has been observed among vectors. Also, the resistance level in some vector species was linked to the quantity of the compound used in the same area against crop pests. Resistance in Anopheles gambiae in Africa, A. albimanus in Central America, A. culicifacies and A. aconitus in South East Asia, A. sacharovi in Turkey, Culex tritaeniorhynchus in the Far East, as well as DDT resistance in Simulium damnosum in West Africa, all seem to be associated with agricultural practices. On the other hand, resistance has not developed in species which, due to their ecology, are not in contact with agricultural insecticides, even in areas where DDT has been applied for >20 years in house spraying. This is the case in A. dirus and A. minimus in Thailand and A. darlingi in South America. However, several vectors such as A. stephensi, Aedes aegypti and C. quinquefasciatus, have developed resistance for which agricultural treatment cannot be held responsible. It nevertheless seems valid to assert that the rise in malaria in certain countries, e.g. India, is due only to the increase of insecticide usage in agriculture following the "green revolution".