''Charissa obscurata'', the annulet or Scotch annulet, is a

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

of the family

Geometridae The geometer moths are moths belonging to the family Geometridae of the insect order Lepidoptera, the moths and butterflies. Their scientific name derives from the Ancient Greek ''geo'' γεω (derivative form of or "the earth"), and ''metro ...

. The species was first described by

Michael Denis Johann Nepomuk Cosmas Michael Denis, also: ''Sined the Bard'', (27 September 1729 – 29 September 1800) was an Austrian Catholic priest and Jesuit, who is best known as a poet, bibliographer, and lepidopterist. Life Denis was born at Schärding ...

and

Ignaz Schiffermüller Ignaz Schiffermüller (born 2 October 1727 in Hellmonsödt; died 21 June 1806 in Linz) was an Austrian naturalist mainly interested in Lepidoptera. Schiffermüller was a teacher at the Theresianum College in Vienna. His collection was present ...

in 1775. It is found in most of Europe including the European part of Russia and in

Asia Minor Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...

, the

Caucasus The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia (country), Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range ...

Armenia Armenia (), , group=pron officially the Republic of Armenia,, is a landlocked country in the Armenian Highlands of Western Asia.The UNbr>classification of world regions places Armenia in Western Asia; the CIA World Factbook , , and ' ...

and

Azerbaijan Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of t ...

. In the mountains it rises up to 1800 meters. The habitat is rocky dry grasslands, boulder corridors, quarries as well as rocky steppe heaths and wine-growing areas. The

wingspan The wingspan (or just span) of a bird or an airplane is the distance from one wingtip to the other wingtip. For example, the Boeing 777–200 has a wingspan of , and a wandering albatross (''Diomedea exulans'') caught in 1965 had a wingspan o ...

is 27–32 mm. It is a variable species, whose ground colour generally reflects the area it inhabits. It is whitish or pale grey in limestone and chalky districts. Darker forms are found in areas with peaty soils. The circular O marks on all four wings are typical but may be vague. The forewings have strongly toothed lines, whose which continue on the hindwings. The margin of the large hindwing is very heavily ruffled and incised, which differ from other species of ''Charissa'' moths. Prout, L. B. (1912–16). Geometridae. In A. Seitz (ed.) ''The Macrolepidoptera of the World''. The Palaearctic Geometridae, 4. 479 pp. Alfred Kernen, Stuttgar
pdf
/ref> The larva is smooth and grey-brown. Adults are on wing from July to August. The larvae feed on various herbaceous plants, including ''

Calluna ''Calluna vulgaris'', common heather, ling, or simply heather, is the sole species in the genus ''Calluna'' in the flowering plant family Ericaceae. It is a low-growing evergreen shrub growing to tall, or rarely to and taller, and is found ...

'' species, '' Viscaria vulgaris'', '' Sedum telephium'' and ''

Rubus ''Rubus'' is a large and diverse genus of flowering plants in the rose family, Rosaceae, subfamily Rosoideae, with over 1,350 species. Raspberries, blackberries, and dewberries are common, widely distributed members of the genus. Most of the ...

'' species.

Melanism and evolution

The British entomologist Albert Brydges Farn (1841–1921) wrote to

Charles Darwin Charles Robert Darwin ( ; 12 February 1809 – 19 April 1882) was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended ...

on 18 November 1878 about his observation that colour variations in the annulet moth related to soil colour. He suggested this was an example of "survival of the fittest", and added that he had found dark moths on a chalk slope where foliage had been blackened by smoke from

lime kiln A lime kiln is a kiln used for the calcination of limestone ( calcium carbonate) to produce the form of lime called quicklime (calcium oxide). The chemical equation for this reaction is : CaCO3 + heat → CaO + CO2 This reaction can take p ...

s. This was an early observation of

industrial melanism Industrial melanism is an evolutionary effect prominent in several arthropods, where dark pigmentation ( melanism) has evolved in an environment affected by industrial pollution, including sulphur dioxide gas and dark soot deposits. Sulphur d ...

, but Darwin does not seem to have responded.

References

External links

The Annulet at ''UKMoths''''Fauna Europaea''
{{Taxonbar, from=Q1638161 Gnophini Moths described in 1775 Moths of Europe Taxa named by Michael Denis Taxa named by Ignaz Schiffermüller