Insects of Britain and Ireland: the families of Lepidoptera
Adults diurnal to nocturnal; relatively short-bodied; relatively slender-bodied (wingspan more than 15 times the thoracic width) to medium built (wingspan more than 8 and less than 15 times the thoracic width); wings in repose spread flat with their lower surfaces more or less appressed to the substrate, or packed with the forewings directed backwards to cover hindwings and abdomen.
Antennae very short; extending to about 0.38–0.45 times the length of the forewing. Antennae of males bipectinate. Eyes glabrous. Ocelli absent. Chaetosemata present (reduced), or absent. Maxillary palps much reduced, or absent. Labial palps ascending (small, slender); 3 segmented. Proboscis fully developed, or absent; if developed, not scaly.
Wingspan 22–42 mm; 12–15 times the thoracic width. Forewings broad; 1.75–1.9 times as long as wide. The outer and hind margins angled at 100–110 degrees. The outer margin convexly curved (in Cilix only), or sigmoid-curved (mostly, the forewings wings characteristically hook-tipped); forewings apically blunt, or hooked (mostly). Hindwings broadly rounded; similar in breadth to the forewings; with a rounded apex; the upper surfaces conspicuously patterned above (mostly, more or less), or plain; with a discal spot, or with a discal spot and with transverse lines, or with neither discal spot nor transverse lines; with a frenulum.
Neuration of forewings and hindwings dissimilar. Forewings 12 veined; with 1 anal vein. The anal veins of the forewings representing 1b only. Forewings lacking a tubular vein 1c. Vein 1b of the forewings obsoletely furcate (the lower furcation vestigial), or simple. The transverse vein complete. Discal cell of the forewings without a tubular media (M) vein. Hindwings 8 veined, or 9 veined; with 1 anal vein, or with 2 anal veins. The anal veins of the hindwings comprising 1a and 1b (or 1a only). Hindwings exhibiting vein 1a; lacking a tubular vein 1c. Vein 1b of the hindwings if present, simple. The transverse vein complete. The hindwing cell emitting more than six veins, or emitting no more than six veins. 6 veins arising from the hindwing cell, or 7 veins arising from the hindwing cell. The cell-derived hindwing veins all arising independently of one another, or 7+8 proximally joined (Cilix). Vein 8 of the hindwings completely independent of the cell, or anastomosing with the upper margin of the cell (from near its base to beyond the middle); approximating to vein 7 beyond the cell (when not anastomosing with the cell), or not approximating to vein 7.
Fore-legs with a tibial epiphysis. Tibiae of middle legs without spurs, or 2-spurred. Posterior tibiae 2-spurred, or 4-spurred.
Tympanal organs present; abdominal.
Eggs, larvae and pupae. Eggs markedly flattened to not flattened; smooth or minutely pitted (finely pitted). Larval prolegs 8 (the anal claspers lacking). On dicot trees - Tilia, Betulaceae, Fagaceae, and woody Rosaceae.
Pupae concealed; above the ground. Empty pupae not becoming protruded.
British representation. Genera 4; 7 species. Cilix glaucata (Chinese Character), Watsonalla binaria (Oak Hook-tip), Watsonalla cultraria (Barred Hook-tip), Drepana curvatula (adventive, not illustrated), Drepana falcataria (Pebble Hook-tip) Falcaria lacertinaria (Scalloped Hook-tip), Sabra harpagula (Scarce Hook-tip).
Classification. Macromoths. Suborder Ditrysia. Superfamily Geometroidea.
Illustrations. • Drepanidae: Newman. • Larvae of Drepanidae and Notodontidae. • Drepana falcataria (Pebble Hook-tip: B. Ent. 555). • Drepana falcataria: B. Ent. 555, legend+text. • Drepana falcataria: B. Ent. 555, text cont.. • Drepana, Falcaria, Sabra, Cilix (Hook-tips): Kirby 31 (part). • neuration: Cilix, Drepana.
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 families of Lepidoptera. Version: 16th May 2016. delta-intkey.com’.