The spruce carpet (''Thera britannica'') 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 ...

in the family Geometridae. The species was first described by

Alfred Jefferis Turner Alfred Jefferis Turner (3 October 1861, in Canton – 29 December 1947, in Brisbane, Queensland, Australia) was a pediatrician and noted amateur entomologist. He was the son of missionary Frederick Storrs-Turner. He introduced the use of dip ...

in 1925. It is a double-brooded species, meaning it has two broods in one year. Its wings are coloured with different shades of grey, but the spring brood tends to have more brown colours.

Distribution

Found from the

British Isles The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...

and

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

through central Europe to the north of the

Carpathian Mountains The Carpathian Mountains or Carpathians () are a range of mountains forming an arc across Central Europe. Roughly long, it is the third-longest European mountain range after the Urals at and the Scandinavian Mountains at . The range stretches ...

. In the north to the south of

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion#Europe, subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, ...

. In the south there are isolated occurrences in the

Pyrenees The Pyrenees (; es, Pirineos ; french: Pyrénées ; ca, Pirineu ; eu, Pirinioak ; oc, Pirenèus ; an, Pirineus) is a mountain range straddling the border of France and Spain. It extends nearly from its union with the Cantabrian Mountains to C ...

, in

Corsica Corsica ( , Upper , Southern ; it, Corsica; ; french: Corse ; lij, Còrsega; sc, Còssiga) is an island in the Mediterranean Sea and one of the 18 regions of France. It is the fourth-largest island in the Mediterranean and lies southeast of ...

, on the Italian peninsula, in the Carpathians and in the mountains of

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...

(including

Peloponnese The Peloponnese (), Peloponnesus (; el, Πελοπόννησος, Pelopónnēsos,(), or Morea is a peninsula and geographic regions of Greece, geographic region in southern Greece. It is connected to the central part of the country by the Isthmu ...

) as well as in

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedon ...

. The species is more common than in the southern areas in the northern regions of the

Alps The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Sw ...

. Outside of Europe, there are confirmed reports from the north-west and north-east of Turkey, Transcaucasia and the Caucasus.

Description

Its wingspan is about . Very similar to grey pine carpet, but is usually more richly marked and greyer in appearance. The ground colour of the forewing varies between light grey to blackish grey. Within the median band there are individual dark brown reddish-brown stains (shapes) which are often marked with a white border. Three or more of these shapes are ovoid areas located towards the trailing edge. The median band is fluted and normally edged narrowly with white. The sub-terminal line is generally well marked. The spring brood is an overall brown rather than grey. Important differential characters are the white marginal line to central band, the distinct sub-terminal line and the dark grey-brown hindwings. It closely resembles ''

Thera obeliscata ''Thera obeliscata'', the grey pine carpet, is a moth of the family Geometridae. It is found throughout north and central Europe and east across the Palearctic to Siberia, and south to the Caucasus and Transcaucasia. In the Alps it can be found a ...

'' See Townsend et al.Martin C. Townsend, Jon Clifton and Brian Goodey (2010)
''British and Irish Moths: An Illustrated Guide to Selected Difficult Species''
(covering the use of genitalia characters and other features) Butterfly Conservation.

Similar species

Itself variable ''Thera britannica'' closely resembles some forms of ''

'' In case of doubt, specialists should be consulted for determination.

Biology

Its flight periods are April to late June (spring brood) and from the end of August to mid-October (autumn brood). The larva feeds on '' Picea abies'' and '' Pseudotsuga menziesii''.

References

External links

Spruce carpet at ''UKMoths''''Butterflies and Moths of Northern Ireland''''Lepiforum e.V.''Difficult Species Guide
Cidariini Moths of Europe Moths of Asia Taxa named by Alfred Jefferis Turner Moths described in 1925 {{Cidariini-stub