Crescents share the subfamily Melitaeinae with Checkerspots (Genera Charidryas, and Euphydryas). There are four species of Crescents and a total of seven species of Checkerspots from both genera. The Checkerspots are separate from the Crescents in their colouration patterning, which contains squarish, black-outlined white patches on the lower wing surface. Crescents are distinguished by the characteristic dark crescents on the lower hind wings. |
Identification: the Northern Crescent is a small black and orange butterfly; females are darker than males, usually with paler yellow markings in the front wing.
Life History: eggs are apple green and larvae are chocolate brown with cream coloured markings. Adults nectar on larval host plants.
Habitat and Range:this species of Fritilliary ranges across western Canada, from Manitoba to British Columbia and north to the Territories.
Host Plants: larvae of this Crescents feed on Aster spp. and goldenrods.
Flight Period: adults fly from mid May to the end of August with peak flight periods in June and July.
Similar Species: the Pearl Crescent (Phyciodes tharos) is largely restricted to the prairies in Alberta, where the Northern Crescent is largely absent. Where both can be found field identification is essentially impossible. The Field Crescent (P. pratensis), which is restricted to mountainous areas of North America, with a few sighting reports on the fringes of the boreal forest, is much darker than the Northern Crescent. In the mountains of Alberta the Variable Checkerspot (Euphydryas chalcedona anicia) is often very common, but is much blacker with square red and yellow markings on the upper wing surfaces.