Summary
Excito-repellancy boxes were used to test the effect of DDT on populations of Anopheles darlingi, A. nuneztovari and Culex pipiens quinquefasciatus from in and around the city of Manaus, Amazonas. The two Anopheline species showed marked escape responses whereas the very resistant Culex population was little affected. The test boxes were also used as resting traps for C. P. quinquefasciatus and in this case slight differences 'between 'the DDT' sprayed box and an unsprayed control were evident. The need to standardize excito-repellancy testes' in order to clarify the concept of behavioural resistance is discussed.