Polites sabuleti is an example of an insect having a univoltine, monophenic high-elevation subspecies and a multivoltine lowland one that produces similar phenotypes only in cold weather. When reared under conditions that induce the warm-weather phenotype in lowland stocks, the montane subspecies P. s. tecumseh continues to produce its usual phenotype, indicating that it has become genetically fixed.
Shapiro, Arthur M.
"Genetics, environment, and subspecies differences: the case of Polites sabuleti (Lepidoptera: Hesperiidae),"
Great Basin Naturalist: Vol. 35
, Article 3.
Available at: http://scholarsarchive.byu.edu/gbn/vol35/iss1/3