About the Dark-Barred Twin-Spot Carpet
Xanthorhoe ferrugata, the dark-barred twin-spot carpet, is a moth of the genus Xanthorhoe in the family Geometridae. It was first described by Carl Alexander Clerck in 1759 and has a Holarctic distribution. It is found in Europe and east to the Russian Far East, Siberia, Tibet and China, south to the Caucasus and Turkey. Also in North America (Alaska to Newfoundland and south to North Carolina and California).
The name-typical form of ferrugata as figured by Clerck and well described by Linné, has the median band reddish or purplish, the distal area very weakly marked (except the costal patch and two dark spots between the radials) often almost entirely white or whitish. An aberration, ab. unidentaria Haw. is a very common and very interesting aberration which has been proved, by my very extensive breeding experiments and those of Dr. Draudt, to be an almost perfect Mendelian "recessive". It differs in having the median band black, not reddish. — ab. coarctata Prout has the median band greatly narrowed, only 1–2 mm. in width; the rest of the markings often in part obsolete. - bilbainensis Fuchs, from Bilbao, said to be a local race, is described... Wikipedia →