Increased activity of attacks on man in DDT-resistant Anopheles maculipennis sacharovi Favre after contact with this insecticide
Alekseev, A.N.; Suvorova, N.I.
Meditsinskaia Parazitologiia i Parazitarnye Bolezni 46(4): 439-444
1977
ISSN/ISBN: 0025-8326 PMID: 927376 Document Number: 119154
DDT-resistant female malaria mosquitoes (A. maculipennis sacharovi) (LC50 > 4%) were found not only to survive after contact with DDT-treated surfaces (2 g/m2), but to attack their prey 2-3 times as actively as similar females without contact with DDT. This phenomenon was observed after 15-30 min of contact with the treated surface and increased insignificantly with prolongation of exposure (by 1.4-fold). The reactions of newly emerged, engorged (II-IV stages after Sella), parous (in I and II gonotrophic cycles) and diapausing females were similar. Upon prolonged free access to prey in a large room treated 24 h previously with 25% DDT emulsion, repeated blood-sucking by the same experimental females was observed in up to 30% of the instances. Frequent blood meals helped to prevent symptoms of DDT poisoning. The maximum increase of the attacking activity was observed in empty females in the II gonotrophic cycle (i.e., the most dangerous epidemiologically) among those tested. The results indicate the increasing epidemiological danger of DDT-resistant Anopheles under conditions of continued use of this drug.