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A micromoth with a wingspan of 15-17 mm, extremely polymorphic forewings and grey hindwings (Powell 1964). Several different wing patterns are known, some of which intergrade. The forewing colorations can range from white with a variable black basal patch and costal triangle, fading to weak markings, or the equivalent with ochreous orange basal patch. Other forms include half white, half black individuals, brown with white markings, to beige with rust markings to unicolored forms. Some specimens show a brown line from the base of the wing to the apex. The males lack a forewing costal fold (Miller 1966, Powell 1962). Acleris variana and Acleris gloverana are extremely similar in their biology and morphology but can be differentiated via genitalia structures. The sacculus in male A. gloverana is broader and less elongated than in A. variana. Female A. gloverana lack a cestum, which is present in A. variana. Furthermore, female A. variana are known to have big abdominal tufts of scales (Powell 1962).

There is only one generation per year. Eggs are placed on the under surface of needles where they overwinter. Eclosion from the eggs start in May. While the first instars feed inside the opening buds, the mid-instars create a nest by webbing together needles and building a silk-lined shelter (Powell 1964). The last instar is free living and pupates in the final feeding site. The first larval instars are bright green with a black head, while in the final instar, the head and the prothoracic shield are both brown. A needle sheath shelter on the host tree is used for pupation (Powell 1964). From July to August, after about 10 to 20 days of pupal stage, the adults of A. variana hatch (Miller 1966, Powell 1964).

Primarily feeds on various fir (Abies) and spruce (Picea) species. Other host records include Thuja plicata, Larix occidentalis, Pseudotsuga menziesii, Tsuga canadensis, Tsuga heterophylla and Populus blasmifera (Miller 1966, Powell 1964). While the larvae generally only feed on new needles, massive outbreaks cause larvae to also feed on buds, shoots and old needles.

From the east coast of Canada and the United states to the Canadian Rockies (Powell and Opler 2009, MPG 2019). In Alberta A. variana has been found in Edmonton, Lake Louise, Winfield, Dry Island Buffalo Jump Provincial Park, Erskine, Big Knife Provincial Park, Lowden Springs Conservation Area and Medicine Lake Provincial Recreation Area.