Farula constricta is a small, moth-like insect, uniform dark brown in color, with a forewing length of 5 mm (0.2 in.) in both sexes. Adults are typical for the genus, have the curved and heavily setate internal branches of segment X, and the swollen mesal lobe of the inferior appendages. Farula constricta is distinguished by a sharp restriction in the mesal lobes of the inferior appendages, and by a constriction at the base of the internal branch of X, both in ventral aspect.
Farula constricta is known from aquatic habitat in high gradient, cold, spring-fed, perennial stream systems in the Columbia River Gorge. Populations of F. constricta appear to be extremely localized and limited to talus slopes, typically found at the base of small waterfalls.
Limiting factors
Habitat alteration or degradation are main threats to this species. Sedimentation, eutrophication, and chemical pollution caused by road construction and impervious surface run-off could impact this species. Trampling and other impacts from human recreation are also of concern. The loss of trees through timber harvest and wildfires poses additional threats as trees provide shade that maintains appropriate water levels and temperatures.
Data gaps
Assess distribution and determine range. Research habitat associations and collect life history information. Obtain current population size and trend data.
Conservation actions
Monitor existing populations and survey suitable habitat for new populations. Continue DNA and eDNA surveys in suitable and suspected habitat. Protect new and existing sites from disturbance. Minimize fine sediments entering occupied streams.
Key reference or plan
Hietala-Henschell, K. and C. Fallon. 2019. Interagency Special Status/Sensitive Species Program (ISSSSP) Species Fact Sheet: Farula constricta. USDA Forest Service Region 6 and USDI Bureau of Land Management Oregon State Office. 19 pp.
