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Because of variations across its range, the most recent information describes E. corrusca as a species complex, quite possibly consisting of several species but not sufficiently studied or understood to differentiate between them (Lloyd 2003). Ellychnia corrusca displays the basic Ellychnia characteristics, which distinguish it from other Alberta fireflies. Its body is a uniform black colour except for a pale prothorax, the pronotum bearing a median and two lateral dark vittae (stripes). Some specimens also have parts of the last two abdominal segments slightly pale and yellowed. The species lacks any pale borders on the elytra, and lacks light organs in both male and female. The pronotum is semi-elliptical and lacks translucent windows, the eyes are small and distantly separated on the head, and the first antennal segment is longer than the third, often quite obviously so. Ellychnia corrusca can be distinguished from “western” Ellychnia species (those ranging from the Rocky Mountains west to the Pacific coast) by its brown-grey elytral pubescence, which give the elytra a dusty appearance. Western species have black elytral hairs. Two other “eastern” species of Ellychnia are recognized, both of them small (7mm). Since size appears to be the principal distinguishing characteristic between E. corrusca and the other eastern species, an elytral length of 6.5mm or greater when identifying specimens of E. corrusca was used for this species page. This follows Rooney and Lewis (2000) who used elytral lengths of 6mm or greater in the identification of E. corrusca.

While life history information concerning E. corrusca in Alberta does not exist, studies done in Massachusetts have greatly contributed to our understanding of the species. It should be noted that particulars such as mating period may be different in Alberta. Adults overwinter a single season in grooves in the bark of trees; overwintering sites appear to be quite specific and are reused by subsequent generations in following years. Sites are often a foot or more off the ground. Minimal movement occurs through the winter months, and adults do not fly from tree to tree during this period. In Massachusetts, 88 to 99% winter survivorship was observed in the field. High fall levels of abdominal fats, especially in the females, may contribute to winter hardiness. Adults begin to fly in March, and mating occurs from early April to mid May for approximately six weeks. Mating occurs on tree trunks, and can last up to 24 hours (longer periods in lab studies). Eggs hatch about 16 days after being laid (Rooney & Lewis 2000). Larval E. corrusca are found within rotting wood (Arnett 2001). Adults will die in late spring, and the larvae pupate some time before snowfall in autumn.

In Massachusetts, adults appear to be fluid feeders, and can be found on both sugar maple sap flows in April and Norway maple flowers in May. Having found adults at the base of trees throughout the spring and summer, Rooney and Lewis (2000) theorized that these were feeding on interstitial fluids of these trees. Dillon & Dillon (1961) describe E. corrusca adults as being on aster and goldenrod in the fall. Arnett (2001) describes the larvae of all lampyrids as being predaceous.