Insects of Britain and Ireland: the genera of grass moths (Pyralidae-Crambinae and Schoenobiinae)
Adults. Face without a conical hairy prominence. Proboscis functional.
Wingspan 22–26 mm. Forewings broad, cf. Chrysocrambus, whitish, and the whole wing irrorated with large black scales; with a broad brown subcostal band which bifurcates postmedianly, narrower sub-dorsal and dorsal ones which thicken subterminally, and narrow interneural ones towards the termen; an oblique, brown, slightly elbowed median transverse line merging with the longitudinal bands, and a thin brown subterminal line which is strongly curved anteriorly and white-edged distally, and the termen ferrugineous-yellowish with indistinct black dots; the cilia golden-metallic. The fringe glistening-metallic. Termen non-sinuate. Ground colour of the forewings ferrugineous brown (irrorated black). Forewings fairly conspicuously patterned with contrasting colours. The patterning fairly complex; comprising both longitudinal streaking and transverse markings (the veins and costal edge somewhat whitish-streaked, a thick obtusely angled ferrugineous-bown median line, a rounded-angulated white one anteriorly darkly edged, and the termen ferrugineous-yellowish with indistinct black dots). Forewings with a median line; transversely dark-lined towards the termen; the subterminal lines fairly conspicuously white-edged, or not white-edged; without conspicuous white marks at or near the apex; with scattered large black scales. Forewing vein 7 arising from vein 8. Hindwings pale grey to dark grey; plain; brownish or fuscous, without marking other than a fine terminal dark line, the cilia whitish and glossy.
Distribution and habitats. Found only in southern England (associated with chalk substrates - coastal cliffs and downs). England. Occurring in coastal locations and inland. Mesophytic habitats and dry places. British species: T. chrysonuchella. Adults abroad May and June.
Larvae. Larvae feeding on monocots; Poaceae (in the stem bases of Festuca ovina and other grasses, living and finally pupating in a slilken tube).
Illustrations. • Thisanotia chrysonuchella, with species of Agriphila, Catoptria, Chrysocrambus, Crambus and Pediasia: Leech, 1886. • Thisanotia chrysonuchella, with Chrysocrambus: Barrett. • Hübner’s original illustrations of Thisanotia (1796).
To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: the genera of grass moths (Pyralidae-Crambinae and Schoenobiinae). Version: 8th June 2016. delta-intkey.com’.