British Insects: Pug moths (Lepidoptera-Geometridae)
Adults. Posterior tibiae of males 4-spurred. Wingspan 21–25 mm. Forewings not noticeably elongate; the outer margin convexly curved; the costa arched; apically blunt to somewhat pointed.
Forewings dingy; fuscous, with only indistinct obtusely angulated darker striae; the edges of the poorly defined geniculate median band marked faintly darker, more strongly so as two dark costal spots which characteristically form the corners of an equilateral triangle with the discal one; the subterminal line obcurely paler in the dusky subterminal facia and dentate towards the costa. The forewing patterning more or less confined to the dark discal spot; dominated by two dark costal spots which form with the discal one the corners of a conspicuous anterior-median triangle; triangle of spots equilateral. Forewings with a dark discal mark. The discal mark shortly elongate (oval); not whitish-edged; black and distinct. Forewing fringes somewhat chequered to not chequered.
Hindwings fuscous like the forewings with only very faint striae and fasciae; even less conspicuously patterned than the forewings; rather plain; transversely striated to without transverse striation (with at the most very faint darker basal-posterior striae); with a clear discal mark (this dark fuscous, shortly linear); the fringes not conspicuously chequered.
The abdomen plain; neither ringed nor banded nor white-based; with a lateral blackish spot (but this small and indistinct, sub-basal).
Neuration. Forewing and hindwing neuration layout including the outlines of te cells revealed in detail by conspicuous darkening.
Genitalia. The male abdominal plate in the form of two sclerotized components broadly joined basally to in the form of a single sclerotized patch with a pair of apical extensions. The bursa copulatrix rather with ornamentation conspicuously restricted in distribution (mostly distal); conspicuously spiny.
Early stages, ecology. Botanically specialised. Foodplants herbaceous-dicotyledonous; Umbelliferae (Apiaceae). The larvae found on Angelica, Heracleum, Pimpinella, Pastinaca; feeding on flowers and seeds.
Months of appearance, distribution. Adults abroad June and July; larvae found September. South-east England, Central-southern England, South-west England, English Midlands, Northern England, Southern Scotland, Northern Scotland, Wales, and Ireland (widespread but local, seemingly absent from the Western Isles, Orkney and Shetland).
Melanism. Melanic f. angelicata dark fuscous to somewhat coppery, marked only by the conspicuous nervures and the conspicuous forewing and less conspicuous hindwing discal marks. Melanics of E. tripunctaria, E. trisignaria, E. subfuscata, E. virgaureata and E. lariceata are not reliably separable without resort to the genitalia.
Special key characters. Hindwings pale fuscous, or fuscous, or pale grey.
Illustrations. • E. trisignaria (Triple-spotted Pug), with larva: Barrett. • E. intricata arceuthata, E. intricata millieraria, E. plumbeolata, E. satyrata and E. haworthiata, with larvae: Barrett. • E. trisignaria (Triple-spotted Pug), with similar pugs: South. • E. trisignaria (Triple-spotted Pug), with other Pugs: Swain.
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’.