The wingspan is 34–40 mm. The forewings are dark earth brown; lines indistinct; inner and outer black with paler edges; submarginal pale, with black wedge-shaped spots before it; claviform stigma obscure, black-edged; orbicular roundish, brown with pale ring; reniform large with paler outline, especially externally; hindwing whitish, the veins dark; termen diffusely brownish; in male white, with termen narrowly grey; — ab. ferruginea Hofm. (Carinthia and the Tyrol) is much paler with a reddish-yellow tint.[1][2][3]
Figs. 4 young larva 4a half grown larva 4b, 4c larva after last moult
Biology
There is one generation per year with adults on wing from the end of July to September.
Larva shining dark brown; thoracic and anal plates black; head brown; dorsal and subdorsal lines narrow, pale yellow; lateral stripe broader; spiracles black. The larvae feed on various grasses, including Nardus stricta, Calamagrostis purpurea, Festuca and Deschampsia species.[4] Larvae can be found from March to July. The species overwinters as an egg.
Subspecies
Tholera cespitis cespitis
Tholera cespitis armena Hacker, 1986
References
^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
^Hermann Hacker, László Ronkay & Márton Hreblay: Hadeninae I. In: Michael Fibiger, David Agassiz & Martin Honey (Hrsg.): Noctuidae Europaeae. Band 4. Entomological Press, Sorø 2002, ISBN 87-89430-07-7, S. 156.
^Walter Forster, Theodor A. Wohlfahrt: Die Schmetterlinge Mitteleuropas. Band 4: Eulen. (Noctuidae). Franckh’sche Verlagshandlung, Stuttgart 1971, ISBN 3-440-03752-5, S. 88.
