Usingeriessa brunnildalis

Distinguished from similar crambid moths by the combination of dark brown forewings with a distinctly lighter median area and anal angle, gray (not brown) hindwings, and small size. The aquatic larval habitat on stream rocks is also diagnostic for this species within its genus.

Small moth with forewing length 7.5–11 mm. Forewings dark brown with lighter median area and anal angle. Hindwings uniformly gray.

Adults occur in terrestrial habitats near streams. Larvae inhabit rocks in streams, specifically those covered in algae.

Recorded in the United States: California and Texas.

Adults active from August to October.

Larvae feed on algae growing on rocks in streams. Adult diet not documented.

Larval stage is aquatic, living on algae-covered rocks in streams. Pupation and other life stages not described in available sources.

Adults are nocturnal and attracted to light. Larvae are aquatic and graze on algae.

Larvae function as primary consumers in stream ecosystems, grazing on periphyton (algae) on submerged rocks. This places them in the aquatic food web as herbivores that may serve as prey for aquatic predators.

No documented economic or agricultural significance. Occasionally encountered by aquatic ecologists and moth enthusiasts.

• Other Usingeriessa speciescongeners share aquatic larval habits but differ in wing pattern and distribution; U. brunnildalis is distinguished by its specific forewing color pattern and southwestern US range
• Other Acentropinaemany have aquatic larvae, but U. brunnildalis is distinguished by the combination of dark brown forewings with light median area and gray hindwings

• moth
• crambid
• acquatic larva
• algae feeder
• southwestern US
• stream habitat
• nocturnal

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