Insects of Britain and Ireland: butterflies
Adults. Wingspan 23–29 mm; the fringes conspicuously light-and-dark banded. Medium built to heavily built; short-bodied; large-headed. The eyes glabrous. Antennae reaching about halfway to the wingtips; inserted fully one half the width of the head apart. The antennal clubs gradual-elongate; curved; not flattened (tapered). Labial palps ascending (pointed). Having all 6 legs fully developed and operational for walking. Fore-legs with a tibial epiphysis. Tibiae of middle legs without spurs. Posterior tibiae 4-spurred (with middle spurs).
Forewings. Forewings apically blunt. The outer and hind margins angled at about 98–100 degrees. The outer margins convexly curved. Uppersides of the forewings black (-ish); contrastingly dark-veined to not conspicuously dark-veined; without a discal mark; patterned over the posterior 2/3 with numerous creamy-white subquadrate spots.
Hindwings. Hindwings broadly rounded; with the outer margins not scalloped. Uppersides of the hindwings blackish; conspicuously dark-veined to not dark-veined; conspicuously patterned; without a discal mark; colour-patterned rather like the forewings, but with the spots in two series.
Undersides of wings. Undersides of the forewings colour-patterned fuscous with creamy white spots, but paler than the upperside.
Undersides of the hindwings suffusely irrorated yellow-ochreous, with larger white spots instead of the smaller yellowish ones of the upperside, and with three additional white spots towards the base; without metallic markings.
Wing venation. Forewings 12 veined; without basally dilated veins. Forewings with 1 tubular anal vein; the anal veins of the forewings representing 1b only; vein 1b simple. Forewings with a discal cell; vein 2 departing from the cell less than three-quarters of the distance from its base (from halfway or below?). All the forewing veins separate.
Hindwings 8 veined; with a praecostal spur; with 2 anal veins; exhibiting vein 1a; the anal veins comprising 1a and 1b. Hindwings with a closed discal cell; the transverse vein complete. 6 veins arising from the hindwing cell (vein 5 lacking). The cell-derived hindwing veins all arising independently of one another.
Eggs, larvae, pupae. Eggs hemispherical (with a small apical depression); longitudinally ribbed (with about 20 ribs). The larvae shortly hairy; concealed feeders (by virtue of drawing leaves together). P. malvae on Rosaceae (e.g., Rubus, Potentilla, Fragaria).
Pupae smooth and rounded; conspicuously patterned (pale brown with dark dorsal and lateral markings, and wing, leg and antennal casings grenish shaded brownish); concealed (in a spun-together leaf).
British representation. 1 species, or 2 species. Pyrgus armoricanus (Oburthür's Grizzled Skipper, adventive), Pyrgus malvae (Grizzled Skipper). The adults abroad May and June.
Status in Britain. Indigenous (P. malvae), or adventive (P. armoricanus, a mainland-European species supposedly found in Norfolk around 1920).
Distribution. Northern Scotland, southern Scotland, northern England, English Midlands, East Anglia, Wales, southeast England, central southern England, southwest England, Isle of Wight, and Ireland. Frequenting open places. Habitats calcareous and non-calcareous.
Classification. Superfamily Hesperoidea. Hesperiidae.
Illustrations. • Pyrgus malvae (Grizzled Skipper): photo. • Pyrgus malvae (Grizzled Skipper): egg, larva, pupa. • Larvae of P. malvae and Erynnis tages: Duponchel (1849). • Carcharodus alceae, Pyrgus armoricanus: Kirby, 1907.
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. 2008 onwards. Insects of Britain and Ireland: butterflies. Version: 16th May 2016. delta-intkey.com’.