{{Short description|Species of moth}} {{Speciesbox | image = Buchenfrostspanner 16. November 005.jpg | image_caption = Male | taxon = Operophtera fagata | authority = (Scharfenberg, 1805) }} '''''Operophtera fagata''''', the northern winter moth, is a moth of the family Geometridae. It is widespread through much of Europe.

== Geographic distribution ==

This species’ range extends through central and northern Europe to southeast Russia. It is widespread in the UK and Northern Ireland.

== Habitat ==

In Europe, this species prefers common beech woodland, but will also use birch.<ref name = "Kellner">Kellner J. 2005. Proposed separation of male ''Operophtera fagata'' (Scharfenberg, 1805) from ''Operophtera fumata'' (Linnaeus, 1758) by their genitalia (Lep., Geometridae). ''Entomologische Nacrichten und Berichte'' '''49:''' 191 – 193.</ref> The larvae feed on apple (''Malus''), plum, cherry (''Prunus''), birch (''Betula''), lime (''Tilia''), beech (''Fagus'').<ref>name = "Carter", Carter DJ. 1984. Pest Lepidoptera of Europe, with special references to the British Isles. Dr W Junk Publishers.</ref>

== Morphology ==

=== Egg ===

The oval egg is blunt at the micropyle end and has a strongly reticulated surface. It is pale green at first, becoming pale orange.<ref name="name = Carter">name = "Carter"</ref>

=== Caterpillar ===

The larva is initially greenish black with white lines along the body and black or dark brown head. It gradually becomes more yellowish green.<ref>name = "Hylen", Hylen G, Krokene P, Larsson JY, Solheim H, Timmermann V. 2007. A guide to the identification of damage causes – Norwegian National List. The Norwegian Forest and Landscape Institute</ref>

=== Pupa ===

The pupa is yellowish brown and larger than in ''O. brumata''. The cremaster comprises a short, stout shaft with long divergent spikes.<ref name="name = Carter"/>

=== Adult ===

The adult male measures up to 33&nbsp;mm in body length. The forewings are silvery greyish brown with dark brown crossbands. The hindwing is yellowish white. The head and body are pale yellowish brown. The female is smaller and has greatly reduced wings, so is flightless.

== Similar species ==

This species morphologically resembles its congener ''Operophtera brumata'', but males of ''O. fagata'' are slightly larger and do not have the brown underwings characteristic of ''Operophtera brumata''. Microscopically, there are also clear differences in the morphology of the genitalia between the two species. In ''O. fagata'', the uncus is more pointed with a broader and flatter base that is more triangular in ''O. brumata'' (Kellner, 2005). Although co-occurring in the same habitat with overlapping flight times, the two species do not interbreed, which is probably because females produce species-specific pheromones that attract males of only their own species.<ref>Szocs G, Tóth M, Kárpáti Z, Zhu J, Löfstedt C, Plass E, Francke W. 2004. Identification of polyenic hydrocarbons from the northern winter moth, ''Operophtera fagata'', and development of a species-specific lure for pheromone traps. ''Chemoecology'' '''14''': 53 – 58.</ref> == Reproduction and life history ==

From mid-May until early June, mature larvae fall from trees to the woodland floor to pupate in the soil. They remain there until October and November when adults emerge to reproduce.<ref name = "Tomalak">Tomalak M. 2003. Biocontrol potential of entomopathogenic nematodes against winter moths (''Operophtera brumata'' and ''O. fagata'') (Lepidoptera: Geometridae) infesting urban trees. ''Biocontrol Science and Technology'' '''13(5)''': 517 – 527.</ref> Wingless females crawl up tree trunks, while males fly in swarms at night to encounter females to mate with. Females lay eggs on twigs close to leaf buds in November, where they overwinter.<ref name = "Tomalak"/> In the UK, adults are active October - December. The larvae hatch April – May, which in Europe happens at the same time as birch leaves come out.<ref>name = "Hylen"</ref>

== Pest status == The larva of this moth can be a serious pest of fruit trees in northern Britain by attacking the foliage and blossom.<ref name="name = Carter"/> Damage to fruit trees by defoliation is more likely when birch trees, a natural host plant, are growing nearby.<ref>Briggs JB. 1956. Notes on the biology of and identification of some allies of the winter moth (''Operorophtera brumata'' (L.)). 43rd Report to East Malling Research Station 1955: 141 – 145.</ref> In Northern and Central Europe, the larva is a serious defoliator of beech and birch plantations and can sometimes destroy whole seedling plantations.<ref>Escherich K. 1931. ''Die Forstinsekten Mitteleuropas''. Tom. 3. D-Berlin: Paul Parrey, pp. 558 – 595</ref>

thumb|left|200px|Caterpillar thumb|center|200px|Female {{Clear|left}} === References === {{Reflist}}

=== External links === {{Commons category}} * [https://ukmoths.org.uk/show.php?bf=1800 Northern winter moth at UK Moths] * [https://fauna-eu.org/cdm_dataportal/taxon/0a0c24be-04f7-4c8e-a2ea-f73644fe1128 Fauna Europaea] * [http://www.lepiforum.de/lepiwiki.pl?Operophtera_Fagata Lepiforum.de] * [http://www.vlindernet.nl/vlindersoort.php?vlinderid=223 Vlindernet.nl {{in lang|nl}}]

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Category:Operophtera Category:Moths described in 1805 Category:Moths of Europe Category:Moths of Asia