Resapamea diluvius

Distinguished from similar Resapamea species by forewing color pattern: mixture of gray brown, gray tan, red brown, gray, and blackish-gray scales with medium-dark to dark gray brown or reddish-gray brown ground color. Hindwing with slightly brownish gray base, darker distal half, gray ill-defined oval discal spot, and thin terminal line. Size range and Columbia Basin distribution also aid identification.

Forewing length 16–19 mm in males, 15–18 mm in females. Forewings mixture of gray brown, gray tan, red brown, gray, and blackish-gray scales; ground color medium-dark to dark gray brown or reddish-gray brown. Hindwing dorsal surface slightly brownish gray, darker and grayer on distal half, with gray ill-defined oval discal spot and thin terminal line.

Columbia Basin scablands and associated habitats in Washington and northern Oregon; possibly sand dune habitats in northern Nevada and northern Great Plains.

Confirmed: Columbia Basin, Washington and northern Oregon. Possible: northern Nevada dunes, northern Great Plains.

Adults active late April to early June.

Larvae probably feed on Rumex venosus (winged dock).

• Rumex venosus - probable larval hostBased on probable feeding association; not confirmed

Named for geological history of its habitat; etymology references Ice Age floods (diluvium = deluge/flood) that scoured the Columbia Basin.

• Other Resapamea speciesSimilar genus members share general noctuid morphology; R. diluvius distinguished by specific forewing color mixture and Columbia Basin distribution

• endemic
• Pacific Northwest
• scablands
• Ice Age floods

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy