An electrophoretic survey of the phosphoglucomutase (PGM) enzyme was performed using agar gels in 6 strains (3 Japanese strains and 3 strains from Taiwan, Thailand and Canada) of Aedes togoi. The survey revealed at least 3 alleles involved at the Pgm locus among the 6 strains examined. Backcross experiments showed that the Pgm locus was located on the sex chromosome in the following order: Odh (octanol dehydrogenase)--M(sex)--(13.8 map units)--Pgm--(17.0 map units)--h(hooked leg)--s(straw-colored larva).