British Insects: the Families of Lepidoptera
Adults nocturnal; relatively medium-bodied; medium built (wingspan more than 8 and less than 15 times the thoracic width) to heavily built (wingspan less than 8 times the thoracic width); wings in repose packed with the forewings directed backwards to cover hindwings and abdomen.
Antennae very short to of medium length; extending to about 0.45–0.55 times the length of the forewing. Antennae of males dentate, or simple (then filiform); non-ciliate (when filiform), or simply-ciliate. Ocelli absent. Chaetosemata absent. Maxillary palps well developed, or much reduced, or absent; 1 segmented, or 3 segmented. Labial palps porrect; 3 segmented. Proboscis absent.
Wingspan 16–32 mm; 7–10.6 times the thoracic width. Forewings broad; 1.6–2.1 times as long as wide. The outer and hind margins angled at 100–105 degrees. The outer margin convexly curved; forewings apically blunt. Hindwings broadly rounded; similar in breadth to the forewings; with a rounded apex; the upper surfaces plain; with neither discal spot nor transverse lines; with a frenulum.
Neuration of forewings and hindwings dissimilar. Forewings 13 veined; with 2 anal veins. The anal veins of the forewings comprising 1b and 1c. Forewings exhibiting a tubular vein 1c. Vein 1b of the forewings furcate proximally. The transverse vein complete. Discal cell of the forewings containing a tubular media (M) vein (likewise that of the hind-wings). Hindwings 10 veined; with 3 anal veins. The anal veins of the hindwings comprising 1a, 1b and 1c. Hindwings exhibiting vein 1a; exhibiting a tubular vein 1c. Vein 1b of the hindwings simple. The transverse vein complete. The hindwing cell emitting more than six veins, or emitting no more than six veins. 7 veins arising from the hindwing cell (including the anastomosed vein 8). The cell-derived hindwing veins 6+7 proximally joined (connate). Vein 8 of the hindwings joined to the cell only by a bar (Heterogenea), or anastomosing with the upper margin of the cell (Apoda); not approximating to vein 7.
Fore-legs without a tibial epiphysis. Tibiae of middle legs without spurs (rarely), or 2-spurred. Posterior tibiae without spurs, or 2-spurred, or 4-spurred.
Tympanal organs absent.
Eggs, larvae and pupae. Eggs markedly flattened (scale-like); smooth or minutely pitted. Larval prolegs 0 (lacking altogether). Larvae with urticating hairs, or without urticating hairs; exposed feeders. On Quercus, Fagus and Populus.
Pupae concealed; above the ground (in a cocoon attached to a leaf). Empty pupae protruded from place of concealment.
British representation. Genera 2; 2 species. Apoda limacodes (Festoon), Heterogena asella (The Triangle).
Classification. Macromoths. Suborder Ditrysia. Superfamily Zygaenoidea.
Illustrations. • Apoda limacodes (Festoon: Newman). • Apoda limacodes (Festoon: Kirby). • Apoda limacodes, neuration. • Heterogenea asella (Triangle): Stephens II, 1830. • Sterrhopteryx fusca (male and apterous female): Stephens II, 1830.
To view illustrations with legends giving names in current use, 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, as well as source references and other relevant material.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. British insects: the families of Lepidoptera. Version: 29th December 2011. http://delta-intkey.com’.