British Insects: Pug moths (Lepidoptera-Geometridae)
E. prolongata Dietze.
Adults. Posterior tibiae of males 4-spurred. Wingspan 24–26 mm. Forewings distinctly elongate to not noticeably elongate; the outer margin convexly curved; the costa more or less straight; apically blunt to somewhat pointed.
Forewings relatively conspicuously patterned; light fuscous or ochreous-brownish mixed whitish, with conspicuously contrasting, uninterrupted pale silvery-grey striae and fasciae angulated near the dark-and-pale-spotted costa, and a pale almost straight postmedian band crossed near the apex by a short oblique white streak linking it to the finely wavy pale subterminal line; some dark marking of veins in the disc. Forewings without a discal mark (or this very obscure). Forewing fringes conspicuously chequered.
Hindwings very pale greyish, paler towards the base, with a faint narrow curved whitish median fascia and very indistinct dark postmedian striae; less conspicuously patterned than the forewings; fairly conspicuously patterned (paler than the forewings); faintly transversely striated; without a clear discal mark; without a pale tornal spot (but with a small dark one); the fringes rather conspicuously chequered.
The abdomen conspicuously patterned; neither ringed nor banded nor white-based; with fuscous lateral spots (according to Meyrick).
Genitalia. The male abdominal plate in the form of a single sclerotized patch with entire apex (this triangular). The bursa copulatrix with ornamentation conspicuously restricted in distribution (mostly to the distal third); fairly coarsely, conspicuously spiny.
Early stages, ecology. Botanically very specialised. Foodplants herbaceous-dicotyledonous; Compositae (Asteraceae). The larvae found on Sea Wormwood, Seriphidium maritimum, in captivity taking Artemisia abrotanum; feeding on flowers, buds, and leafy shoots.
Months of appearance, distribution. Adults abroad May, June, July, and August; larvae found July, August, and September. South-east England, English Midlands, and Northern England (apart from occasional probable vagrants, confined to south Yorkshire, Lincolnshire and north Essex, in coastal salt-marshes).
Special key characters. Hindwings whitish, or pale grey.
General comments. This species is represented in the British Isles exclusively by subsp. occidua Prout, in which the wing patterning is brighter.
Illustrations. • E. extensaria (Scarce Pug), with larva: Barrett. • E. extensaria (Scarce Pug), with other pugs: South. • E. extensaria (Scarce Pug), with other Pugs: Swain (5).
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. British insects: Pug moths (Lepidoptera-Geometridae). Version: 29th December 2011. http://delta-intkey.com’.