MORPHOLOGY

External characteristics

Male
Forewing length (mm): 61-71. Wingspan (mm): 103-126.
Forewings: Upperside black with following pale ochreous markings: narrow submarginal spots, stripe along hind margin, most of space 1bc, 2 and 3, small median dots in spaces 4 and 5, well developed median spots in spaces 6-8, four stripes in basal half of cell, cross band in upper half of cell, vaguely pale ochreous along discocellular veins; underside similar, but paler ochreous more extended. Hindwings crenulate, with strong spatulate tail at end of vein 4; upperside dark brown/black, straight pale yellow band in basal 1/3 from inner margin to front margin, strongly developed, separate, pale yellow submarginal spots, a bit orange in space 1b; underside basal area finely dusted with pale yellow scales, veins beyond cell finely outlined in gray, submarginal spots large, confluent and extended along veins almost to wing margin, irregular blue line at the median spots location, dirty orange color at bases of spaces 3-6, forming semicircle around cell and extended along the veins to the blue median line.

Female
Forewing length (mm): 61-70. Wingspan (mm):112-116.
Similar to male, but the pale yellow is paler and can be almost white.

Subspecies and variation

Geographic variation in the width of the bands and the intensity of the colors; three subspecies have been distinguished.

Similar species

P. gigon is a large edition of P. demolion. The two species do not occur together, P. gigon being a more eastern species, but in case of uncertainty, the large orange semicircle on the underside of the hindwing in P. gigon easily sets this species apart.

_{source: Jan Moonen, peronal communication 2020}