Spodolepis substriataria

Distinguished from similar Spodolepis species by the combination of fine substriate (finely lined) forewing patterning and the pale, relatively unmarked hindwings. S. substriataria shows more pronounced longitudinal striation than S. fulvibasis, which has warmer basal coloration. The species can be separated from other western Ennominae with striate forewings by its boreal distribution and relatively small size. Genitalia examination may be required for definitive identification where ranges overlap with congeners.

Adults are medium-sized geometrid moths with wingspans approximately 25–30 mm. Forewings are pale grayish-brown with fine, darker striations that give the species its name; transverse lines are typically faint but may be more distinct in some individuals. Hindwings are paler, nearly uniform in color, lacking strong patterning. The body is slender and covered in fine scales matching the wing coloration. Antennae are filiform and relatively simple in structure.

Occupies boreal forest, taiga, and northern temperate woodland habitats. Found in coniferous and mixed forests, particularly in association with spruce (Picea), fir (Abies), and pine (Pinus) stands. Also occurs in riparian corridors, forest edges, and open woodlands. Elevation range extends from lowlands to subalpine zones in western mountain ranges.

Transcontinental across northern North America. Range extends from Alaska and Yukon eastward across all Canadian provinces to Newfoundland and Labrador. Southern limits reach northern California in the west, with disjunct or marginal records in the northeastern United States including Vermont and New Jersey.

Adults are active primarily from late May through August, with peak activity in June and July. Timing varies with latitude and elevation; northern populations fly later in the season. Most records fall within this single-generation (univoltine) flight period, though some southern populations may show partial second emergence.

Life cycle details are poorly documented. Larvae are presumed to feed on coniferous foliage given habitat associations, though specific host plant records are lacking. Pupation likely occurs in soil or leaf litter. Overwintering stage is inferred to be larval or pupal based on related Ennominae, but not confirmed.

Adults are nocturnal and attracted to light. Flight activity peaks during warm, humid evenings. Resting posture typical of Geometridae: wings held flat or slightly tented over the body. Larval behavior unrecorded; expected to exhibit characteristic looping locomotion of geometrid caterpillars.

Adults serve as prey for nocturnal insectivores including bats and night-foraging birds. Larval herbivory, if confirmed on conifers, would contribute to nutrient cycling in boreal forest ecosystems. Population dynamics likely influenced by forest disturbance regimes.

No significant direct economic impact. Occasionally encountered by forest entomologists and biodiversity surveys. Not considered a forestry pest. Presence serves as an indicator of intact boreal and northern temperate forest habitats.

• Spodolepis fulvibasisOverlapping western range; distinguished by warmer orange-brown basal forewing coloration and less distinct striation.
• Spodolepis hypenoidesSimilar size and pattern; requires genitalia examination for separation in areas of sympatry.
• Lomographa semiclarataSympatric Ennominae with striate forewings; larger size and more contrasting wing pattern distinguish it.

• Geometridae
• Ennominae
• boreal moth
• North America
• coniferous forest
• nocturnal
• light-attracted

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life