DDT-RESISTANCE IN WEST AFRICAN AND ASIAN STRAINS OF AEDES AEGYPTI (L)

  • 1 January 1967
    • journal article
    • research article
    • Vol. 36  (3) , 409-+
Abstract
The yellow fever mosquito Aedes aegypti has developed resistance to DDT in the Caribbean region and in South-East Asia, but not in West Africa. Therefore West African strains were compared with South-East Asian strains for their response to laboratory selection with DDT. It was found that West African strains were much slower to respond initially, but eventually could build up a high degree of DDT-resistance. By crossing and backcrossing with a susceptible marker-gene strain, it was found that this resistance was due to a single gene linked with the gene y (yellow) on chromosome 2 at a cross-over distance of approximately 35 units in an Upper Volta strain as in a Bangkok strain; interstrain crosses indicated that the gene was the same as that in a Trinidad strain and in 1 from Penang. Dieldrin-resistance could be readily induced in the Upper Volta strain and proved to be due to a gene also linked with y but at a crossover distance of approximately 25 units, comparable to that in Caribbean strains previously studied. Material from Karachi, West Pakistan, developed a dieldrin-resistance also showing 25% crossing over with y, and a DDT-resistance also linked with this chromosome-2 marker gene.