The double square-spot (''Xestia triangulum'') is a
moth of the family
Noctuidae
The Noctuidae, commonly known as owlet moths, cutworms or armyworms, are a family of moths. They are considered the most controversial family in the superfamily Noctuoidea because many of the clades are constantly changing, along with the other f ...
. It is distributed through most of
Europe except Portugal, the Mediterranean islands and northernmost Fennoscandia. In the East, the species ranges East across the
Palearctic
The Palearctic or Palaearctic is the largest of the eight biogeographic realms of the Earth. It stretches across all of Eurasia north of the foothills of the Himalayas, and North Africa.
The realm consists of several bioregions: the Euro-Sibe ...
to
Siberia and in the South-East to the
Black Sea and in
Iran. It rises to a height of about 2000 metres in the
Alps.
This species has pale brown forewings marked with two distinctive black marks. Despite the common name, only one of these is square, the other being roughly triangular. The hindwings are similar in colour to the forewings. It is very similar to ''
Xestia ditrapezium
''Xestia ditrapezium'' (triple-spotted clay) is a moth of the family Noctuidae found in most of Europe, northern Turkey, northern Iran, Transcaucasia, Caucasus, central Asia, from the Altai to Ussuri, Amur, Kuril Islands, northern Mon ...
''.
Differences:
*''Xestia ditrapezium'' Front wing on average narrower (or longer). Ground colour of the forewings usually darker (red to violet-brown) and colour of the rear wing a shade lighter. Hindwings are significantly lighter than the Forewings.Collar without contrasts, almost monochrome.
*''Xestia triangulum'' Forewings average wider (or shorter). Ground colour of the forewings of usually lighter (ochre to tawny or grayish brown) colour of the hindwings usually slightly darker grey. Hindwings about as light as the front wings. Lower part of the neck collar grey, separated by a light line from the dark upper.
Technical description and variation: The
wingspan is 36–46 mm. Forewing grey brown, with a rufous tinge: a small blotch at base, a praeapical costal spot, and the cell prominently black brown; hindwing fuscous.
[Seitz, A. Ed., 1914 ''Die Großschmetterlinge der Erde'', Verlag Alfred Kernen, Stuttgart Band 3: Abt. 1, Die Großschmetterlinge des palaearktischen Faunengebietes, Die palaearktischen eulenartigen Nachtfalter, 1914]
The moth flies at night in June and July in the
British Isles. It is attracted to light and sugar and to
flowers such as
wood sage.
The
larva is ochreous brown, black speckled ; the lines pale ; a row of oblique dark subdorsal bars. It is
polyphagous
Feeding is the process by which organisms, typically animals, obtain food. Terminology often uses either the suffixes -vore, -vory, or -vorous from Latin ''vorare'', meaning "to devour", or -phage, -phagy, or -phagous from Greek φαγε ...
, feeding on a wide variety of plants including birch, blackthorn, bramble, Rumex, dock, Crataegus, hawthorn, raspberry and Goat willow, sallow. The species overwinters as a larva.
Inhabits preferably forest edges, slopes covered with shrubs, heaths and gardens and parkland.
References
*Chinery, M. ''Collins Guide to the Insects of Britain and Western Europe''. 1986 (Reprinted 1991)
*Skinner, B. ''Colour Identification Guide to Moths of the British Isles''. 1984
External links
LepiforumFunetFauna Europaea
{{Taxonbar, from=Q2097524
Xestia
Moths described in 1766
Moths of Europe
Moths of Asia
Taxa named by Johann Siegfried Hufnagel