Genetical studies on dieldrin-resistance in Aedes aegypti and its cross-resistance to DDT.

A strain of Aëdes aegypti was recently found in Puerto Rico which proved to be resistant to both DDT and dieldrin. This paper reports on genetical studies of this strain to determine whether a single entity is involved or two distinct resistances. Tests carried out by repeated back-crossing combined with selection pressure from DDT and dieldrin and by crossing with a strain with marker genes indicate that a single entity is responsible (dieldrin-resistance with cross-resistance to DDT) and that its genetic factor is located on chromosome 2 at a distance of 25 from locus "yellow".