Abstract
Aphid pests are becoming an increasingly serious problem, in which an enhanced supply of nitrogen in the soil, the introduction of selective herbicides and the enlarged area of certain crops are possibly relevant factors. It has been accentuated by the development of insecticide-resistant strains, some confined to particular crops and areas, others affecting several crops in many parts of the world. Concerted action is needed, involving the use of selective insecticides in integrated pest control programmes and further research to develop a broader range of such insecticides.