Coliadinae

Coliadinae, the sulphurs or yellows, are a subfamily of butterflies with about 300 described species.
There are 36 species in North America, where they range from Mexico to northern Canada. In most species, males are easily distinguished from females. For example, in the genera Colias and Gonepteryx), males exhibit brilliant UV reflections that the females lack.

Systematics

Molecular phylogenetic analyses have found that the Coliadinae consists of two, well-supported and reciprocally monophyletic groups, which have variously been referred to as the Colias-clade and the Eurema-clade or as the tribes Euremini and Coliadini.
The genera are as follows:
ColiadiniGandaca Moore, Gonepteryx Leach, – brimstonesDercas Doubleday, - sulphursPhoebis Hübner, Aphrissa Butler, 1873Catopsilia Hübner, – emigrantsAnteos Hübner, – angled-sulphursZerene Hübner, Colias Fabricius, 1807 – clouded yellowsPrestonia Schaus, 1920Rhabdodryas Godman & Salvin,
EureminiKricogonia Reakirt, 1863Nathalis Boisduval, Pyrisitia Butler, 1870Teriocolias Roeber 1909Leucidia Doubleday, Eurema Hübner, – grass yellowsAbaeis Hübner, Terias Swainson, 1821
Historically, the Coliadinae were arranged in three tribes- Euremini, Goniopterygini, and Coliadini- and a basal lineage, with one genus, Gandaca, of unclear placement.