Insects of Britain and Ireland: butterflies
Adults. Wingspan 25–30 mm; the fringes not banded. Medium built; short-bodied to medium-bodied. The eyes white-rimmed; notched or emarginate at the bases of the antennae and contiguous with the bases of the antennal sockets; hairy, or glabrous (?). Antennae reaching noticeably less than halfway to the wingtips to reaching about halfway to the wingtips. The antennal clubs gradual-elongate to abrupt (elongate?). Labial palps ascending. Having all 6 legs fully developed and operational for walking. Fore-legs without a tibial epiphysis. Tibiae of middle legs 2-spurred. Posterior tibiae 2-spurred.
Forewings. Forewings apically blunt to pointed. The outer margins convexly curved to more or less straight. Uppersides of the forewings violet- blue (males), or purple, or fuscous (females); without a discal mark; in the males, deep violet with a narrow black border; in females, dusky brown with violet on the disc.
Hindwings. Hindwings broadly rounded, or trapezoidal (more rounded than in Lampides boeticus); tailed; the tail filamentous and delicate (from vein 2). Uppersides of the hindwings violet- blue (males), or purple, or fuscous (females); conspicuously patterned, or plain; without a discal mark; in the males, deep violet with a narrow black border; in females, dusky brown with violet on the disc.
Undersides of wings. Undersides of the wings transversely patterned with numerous pale, sinuous lines.
Undersides of the forewings grey-brown, with numerous flexuose pale lines. Undersides of the forewings completely traversed ante-medianly by transverse lines (i.e., by contrast with Lampides boeticus, where they do not extend beyond the discal cell).
Undersides of the hindwings grey-brown with numerous flexuose pale lines, and at the anal angle near the tail two small, orange-bordered spots containing metallic green; with 1–2 black dots within small orange spots near the tornus; eye-spotted. The eye-spots 2; near the tornus. Undersides of the hindwings without a discal mark; with silvery-metallic markings.
Wing venation. Forewings 11 veined (?). Forewings with 1 tubular anal vein; the anal veins of the forewings representing 1b only; vein 1b furcate proximally to simple. Forewings with a discal cell. Forewing veins 7 missing, 8 and 9 stalked, 6 out of 9.
Hindwings 9 veined; without a praecostal spur; with 2 anal veins; exhibiting vein 1a; the anal veins comprising 1a and 1b. 7 veins arising from the hindwing cell. The cell-derived hindwing veins 3+4 proximally joined (connate only).
Eggs, larvae, pupae. The larvae woodlouse-shaped; associated with ants in the later instars. On Lotus, Melilotus, etc.
Pupae smooth and rounded.
British representation. 1 species. Leptotes pirithous (Bloxworth Blue, Langs Short-tailed Blue). The adults abroad August.
Status in Britain. Rare ocurrence representing occasional, genuine immigrants (from mainland-Europe).
Distribution. Central southern England.
Classification. Superfamily Papilionoidea. Lycaenidae.
Illustrations. • Leptotes pirithous (Lang’s Short-tailed Blue). • Leptotes pirithous (Lang’s Short-tailed Blue): From Hübner, 1805). • Plebicula dorylas, Leptotes pirithous: 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’.