Blue Underwing
Common NameBlue Underwing
Scientific NameCatocala fraxini
FamilyErebidae
SubfamilyErebinae
Wingspan (mm)90
Primary Colorsgrey, brown, black, blue, white
HabitatDeciduous and mixed woodlands, parks, gardens, riverbanks
Geographic RangeEurope, Asia, North Africa
Host Plantsash, poplar, aspen, willow
Flight PeriodJuly to October
Conservation Statusleast-concern
Lifecycle NotesEggs overwinter, larvae hatch in spring to feed on host tree leaves, pupate in early summer, and adults emerge from late summer into autumn.
Identification TipsKey features include its large size, the mottled grey forewings resembling tree bark, and the distinctive bright blue band on the dark hindwings, often flashed when disturbed.
Description
A large moth with highly cryptic, bark-like grey and brown forewings, which conceal vibrant dark hindwings featuring a striking broad blue band and a white-fringed margin.
