Inheritance of dieldrin-resistance in Cimex lectularius L. and Pediculus h. humanus L.

The following is substantially the authors' summary. To investigate the mode of inheritance of dieldrin resistance in Cimex lectularius L. and Pediculus humanus humanus L., reciprocal crosses were made between normal (N) and resistant (R) strains of each species, and the susceptibility of the N parent strain and the F1 and F2 progeny was examined by exposure to a range of concentrations. Back-crosses were made from the F1 generation to the N and R strains, and the progeny examined in the same way. In some cases, further back-crosses were made after elimination of susceptible individuals from the progeny of the first back-cross. All the results with C. lectularius were consistent with monofactorial inheritance of resistance through a gene of intermediate dominance [cf. R.A.E., B 52 6, etc.]. With P. h. humanus, the results were complicated by an apparent maternal effect that caused the F1 and F2 generations from a cross between an N female and an R male to be less resistant than those from the reciprocal cross. In general, however, the results indicated genetic segregation consistent with the same type of monofactorial inheritance as that found in C. lectularius.