MORPHOLOGY
External characteristics
Male 
Forewing length (mm): 52-55. Wingspan (mm): 76-88. 
Forewings: Upperside without or with faint pale stripes on both sides of veins in apical half; underside xxxxx??  Hindwings Hindwing outer margin slightly crenulate, large anal fold that varies from grayish black to beige or whitish; upperside black; underside xxxxx?
Female  
  
Subspecies and variation
Varies geographically in size, intensity and extent of pale markings; nine subspecies have been distinguished.
Similar species
Not easily confused with other species.
source: Jan Moonen, peronal communication 2020