Depressaria alienella
Busck, 1904
Yarrow Webworm
Depressaria alienella is a small in the Depressariidae, described by August Busck in 1904. It occurs across northern and western North America, from Yukon to Nova Scotia and south to Arizona and California. The larvae feed on flowers of Artemisia and Achillea . are active from July through September.
Identification
Small size (18–21 mm wingspan) and distinctive forewing pattern with white discal spot distinguish this from most similar Depressaria. The reddish-fuscous ground color with blackish streaking and marginal spot pattern separate it from ; examination of genitalia may be required for definitive identification.
Images
Habitat
Associated with plant : open areas, meadows, and disturbed sites where Artemisia and Achillea grow.
Distribution
North America: Yukon to Nova Scotia, south to New England, Arizona, and California. Additional records from Alberta, Manitoba, and Saskatchewan.
Seasonality
on wing July to September.
Diet
Larvae feed on flowers of Artemisia and Achillea .
Host Associations
- Artemisia - larval flowers
- Achillea - larval flowers
Ecological Role
Herbivore; larval flower-feeding may influence seed production of plants.
Human Relevance
Minor; occasional presence in gardens where yarrow (Achillea) is cultivated.
Similar Taxa
- Depressaria radiellaSimilar size and pattern; D. radiella has more prominent dark markings and different associations (Apiaceae).
- Depressaria pastinacellaOverlaps in range and size; distinguished by plant (Pastinaca) and more uniform forewing coloration.