Insects of Britain and Ireland: butterflies

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L. Watson and M. J. Dallwitz

Thymelicus

Adults. Wingspan 24–28 mm (acteon), or 26–30 mm (lineola), or 27–34 mm (sylvestris); the fringes not banded. Medium built to heavily built; medium-bodied to long-bodied; large-headed. The eyes glabrous. Antennae reaching noticeably less than halfway to the wingtips to reaching about halfway to the wingtips; inserted fully one half the width of the head apart. The antennal clubs gradual-elongate; slightly curved to not curved; slightly flattened to not flattened, or not flattened (the clubs black underneath in T. lineola, not so in the others); not hooked at their tips. 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 95–105 degrees. The outer margins convexly curved. Uppersides of the forewings light brown to dark brown, or light brown to orange-brown, or fuscous; contrastingly dark-veined, or not conspicuously dark-veined.

Hindwings. Hindwings broadly rounded; with the outer margins not scalloped. Uppersides of the hindwings light brown to dark brown, or light brown to orange-brown, or fuscous; conspicuously dark-veined, or not dark-veined; conspicuously patterned (variously spotted, chequered, dark-bordered), or plain.

Undersides of wings. Undersides of the forewings pale ochreous, medianly suffused orange-ish.

Undersides of the hindwings plain, pale ochreous or (in T. actaeon) suffused orang-ish tornally; 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 about halfway or below). Forewing veins all separate.

Hindwings 8 veined; without a praecostal spur (? - not found); 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 absent). The cell-derived hindwing veins all arising independently of one another. The hindwings lacking vein 5, 8 arising near the base of the cell and rapidly diverging.

Eggs, larvae, pupae. Eggs asymmetric, being horizonally elongate and broadly sausage-shaped in side view (unusual in being elongate in the horizonal plane, instead of circular); more or less smooth. The larvae hairless; exposed feeders. On iGramineae.

Pupae smooth and rounded; conspicuously patterned, or plain; without shining-metallic markings; exposed, with no coccoon, or concealed (sometimes in a slight cocoon); usually not suspended, but attached at the tail and secured by a median girdle of silk.

British representation. 3 species. Thymelicus acteon (Lulworth Skipper), Thymelicus lineola (Essex Skipper), Thymelicus sylvestris (Small Skipper). The adults abroad July and August.

Status in Britain. Indigenous.

Distribution. 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. • Thymelicus acteon (Lulworth Skipper), T. lineola (Essex Skipper) and T.sylvestris (Small Skipper): photos. • Thymelicus lineola (Essex Skipper): photos. • Thymelicus sylvestris (Small Skipper): photos. • Larvae and pupae of T. sylvestris and other Hesperiidae: Duponchel (1849). • Thymelicus acteon (Lulworth Skipper): photos. • Thymelicus acteon, T. lineola and T. sylvestris: eggs, larvae, pupae. • Thymelicus acteon (Lulworth Skipper: B. Ent. 442). • Thymelicus acteon (legend+text: B. Ent. 442). • Thymelicus acteon (text, cont.: B. Ent. 442).


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’.

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