Orange Sulphur
Colias eurytheme
This pinned butterfly specimen was collected in Tucson, Arizona in Aug. 1978. The yellow spots within the black border identify it as a female. Males have solid black borders.
Pieridae -- White and Sulphur Butterfly Family
Alfalfa and clovers are widely cultivated across North America and as a result the Alfalfa Butterfly, as the Orange Sulphur is also known, is found pretty much everywhere in North America. Wingspan varies from 3 cm to 7 with males usually smaller than females. The orange background color of males is darkest, whereas females may have a yellower cast. Rarely, some female orange sulphurs are so pale as to be nearly white. Flight season ranges from mid spring through late fall.
In the Sonoran Desert the Orange Sulphur will be found near cultivated fields of alfalfa (lucerne), but also along riparian corridors where various clovers and other legumes grow. The caterpillars can be found on Yellow Sweet Clover (Melilotus indicus).