Norfolk status Common in gardens and a wide variety of other habitats. The adults are seen from mid May to mid August, and are typically white with black 'peppered' markings. Two darker forms are more common where the trunks of trees are blackened by pollution. This is a classic example of evolution in action and has been much studied.
f. carbonaria: Sooty black, frequent in industrial areas correlating with levels of industrial pollution.
f. insularia: Genetic intermediate form, not a result of mixed mating, again more frequent in polluted areas.
Recorded in 67 (97%) of 69 10k Squares. First Recorded in 1834. Last Recorded in 2020. Additional Stats