Variations in the linkage of the sex allele in laboratory colonies of the mosquito Culex tritaeniorhynchus

Four wild type laboratory strains from Japan appear to have the sex allele M on the third chromosome while all but 1 strain from Pakistan, Bangladesh, and Taiwan have the sex allele on chromosome 1. The one exceptional Pakistan strain with sex on chromosome 3 may be the result of an earlier laboratory contamination from Japanese strains.