Iridopsis clivinaria

Forewing length 22–25 mm distinguishes it from smaller congeners. Adult flight period March–July is earlier than many related species. Larval association with Cercocarpus and Purshia tridentata provides a strong ecological indicator in the western United States and Canada. Subspecies I. c. impia and I. c. profanata differ in geographic distribution and minor morphological traits.

Associated with montane and foothill shrublands where host plants occur. Found in regions with Cercocarpus (mountain mahogany) and Purshia tridentata (bitterbrush) dominance, including sagebrush-steppe ecotones and open coniferous forest understories.

Western North America: British Columbia south through California, east to Idaho, Colorado, and Arizona. Subspecies I. c. clivinaria occupies the core range; I. c. impia and I. c. profanata have more restricted distributions.

Adults active March to July. One generation per year (univoltine). Larval feeding occurs during spring and early summer following egg hatch.

Larvae feed primarily on leaves of Cercocarpus species and Purshia tridentata. Recorded secondary hosts include Prunus species and Ceanothus velutinus. Young larvae skeletonize leaves; older larvae consume entire leaves.

• Cercocarpus - primary hostmountain mahogany species
• Purshia tridentata - primary hostbitterbrush
• Prunus - secondary hostoccasional records
• Ceanothus velutinus - secondary hostsnowbrush ceanothus

Univoltine: one generation per year. Adults emerge March–July. Eggs laid on host foliage. Larvae develop through spring and early summer, with young instars skeletonizing leaves. Pupation presumably occurs in soil or leaf litter, though pupal site not explicitly documented.

Adults are nocturnal and attracted to light. Larvae are foliage feeders with early instars skeletonizing leaves before consuming entire leaves in later development.

Herbivore on dominant western North American shrubs. Larval feeding can cause noticeable defoliation of Cercocarpus and Purshia. Serves as prey for birds, parasitoid wasps, and other insectivores in shrubland ecosystems.

Occasional pest of ornamental Cercocarpus in cultivated settings. Defoliation events can affect rangeland forage quality where Purshia tridentata is important for wildlife and livestock. No significant economic impact documented.

• Iridopsis defectariaOverlapping range and similar gray-brown wing pattern; differs in forewing length and larval host preferences
• Anacamptodes speciesFormerly classified in this genus; distinguished by wing venation and genitalia morphology
• Other Ennominae loopersSimilar looping locomotion in larvae; distinguished by host plant specificity and adult flight period

• geometridae
• moth
• western north america
• shrubland
• univoltine
• skeletonizing feeder
• cercocarpus
• purshia

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life