Acossus undosus

Identification relies on geographic range and association with host plants typical for the genus Acossus. The species may be distinguished from other Acossus species by genitalia dissection and examination by a specialist. The genus Acossus is characterized by larvae that bore into woody plants, particularly Populus and Salix species.

Wingspan approximately 58 mm. As a member of Cossidae, adults likely have broad, relatively heavy bodies and wings that may appear dull-colored or cryptic. Specific coloration and pattern details for this species are not well documented.

Habitat details are not explicitly documented. Based on known host associations for the genus, the species likely occurs in riparian areas and woodlands where Populus and Salix species grow.

Documented from Wyoming and Utah, United States. Possibly present in surrounding states, though this requires confirmation.

Larvae of the genus Acossus are known to bore into and feed on the wood of Populus (poplar) and Salix (willow) species. Specific host records for A. undosus are not confirmed.

• Populus - larval hostgenus-level association; specific host record for A. undosus not confirmed
• Salix - larval hostgenus-level association; specific host record for A. undosus not confirmed

As with other Cossidae, development likely includes egg, larval, pupal, and adult stages. Larvae are wood-borers that tunnel through host plant stems or trunks. Specific timing and duration of life stages for A. undosus are not documented.

Larvae function as wood-borers in living or dead woody plants, contributing to nutrient cycling and creating habitat for other organisms in tunnel systems. As a member of the genus Acossus, the species may serve as prey for woodpeckers and parasitoid wasps.

• Acossus centerensisCongeneric species with similar morphology and ecology; distinguished by geographic range and genitalia characteristics
• Acossus populiLarger congeneric species; A. undosus is smaller with wingspan ~58 mm versus ~75 mm for A. populi

• Cossidae
• carpenter moth
• wood-borer
• western North America

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