One of 13 Coliadinae (sulphur subfamily) species found in Ontario, this sulphur is also known as the Alfalfa Butterfly. As with many Sulphurs, eurytheme's wing pattern and coloration is sexually differentiated. Although it is a resident representative of this genera, C. eurytheme may also be migratory. In southern fields of Alfalfa and clovers, Orange and Clouded (C. philodice) Sulphurs can become quite numerous and are considered agricultural pests. Identification: Males have bright orange upper wings with solid black borders. Spring generation may be smaller with yellow top wing having only a small patch of orange shading in the middle of the wings and a narrower black border. Females have yellow spots in the black border and white females are commonly encountered. Both sexes have a black spot on the top and bottom forewing, and an orange spot on the top hindwing. Also, the undersides of both fore and hindwings have a row of small brown dots near the margin and, on the hindwing, a pink rimmed silver spot. Wingspan: 34-55 mm. Life History: Two to three broods. Reddish colored eggs. Hibernates as larva. Smooth green larvae with a dark dorsal stripe and light lateral stripes. An avid mud-puddler, it is often found with the Clouded Sulphur at mud puddles. Habitat and Range: Clover and Alfalfa fields, roadsides, agricultural areas. In Ontario it is common throughout most of the province and occurs as far north as James Bay. In the Ottawa District it is less common than C. philodice and numbers tend to fluctuate from year to year. Nationally this species is found throughout Canada in all provinces but not the territories. Host Plants: Legume (Fabaceae) plants, especially clovers and Alfalfa (Medicago sativa). Flight Period: In Southern Ontario: May to early November. In the Ottawa District: June (rare), and August to mid-October. Similar Species: In Ontario the similar Clouded Sulphur (C. philodice) can be distinguished by its yellow topwings, eurytheme almost always has orange on its upperside and both sexes have an orange spot on the top hindwing.