British insects: the families of Coleoptera
British insects: the families of Coleoptera | |
Including Drilidae part, Lycidae part.
Glow-worms, Fireflies.
General appearance. 5–16 mm long. Body length/maximum body width 1.7–5.65. Elytral length/pronotal length 0.68–6.9. Base of prothorax not or scarcely narrower than the combined elytral bases. Greatest prothoracic width not narrower or only slightly narrower than the greatest elytral width. Beetles elongate to slender; not necked; not waisted to somewhat waisted; luminescent from distal abdominal sternites (female Lampyris and both sexes of Phosphaenus), or not luminescent (male Lampyris). Upper surfaces of body non-glabrous; not bristly; with neither scales nor scale-like setae.
Detailed morphology. Beetles not prognathous. The head covered by the thorax. Inclination of the head strong to very strong. Eyes strongly protuberant, or not strongly protuberant; without bristles; finely facetted. Antennae very short to about half the insect's head to tail length; 6 segmented, or 8–15 segmented, or 20–40 segmented. Antennal scape not swollen. Antennae filiform. Antennal insertions visible from above; not in fossae. Prothorax shorter than wide. Pronotal length/maximum pronotal width 0.42–0.97. Prothorax without notopleural sutures. The scutellum not elevated. Metaventrite without a transverse groove. Tarsal segmentation formula 5, 5, 5. The tarsi exhibiting bilobed segments; without ‘hidden’ segments. Front tarsi with as many segments as the mid-tarsi; 5-segmented. Mid-leg tarsi 5-segmented; pentamerous. The claws of the mid-leg tarsi not appendaged. The claws of the mid-leg tarsi simple, or one-toothed or bifid; without an associated empodium. Hind tarsi with as many segments as the mid-tarsi; 5-segmented. Elytra present (males), or absent (females). Elytral length/maximum width across the elytra 0.38–2.9. Elytra individually distinctly tapered to their apices (or rounded?); not meeting along the full length of the mid-line; (of males) covering most to all of the abdomen (Lampyris), or short, exposing several terminal abdominal tergites (Phosphaenus); exposing when long, no more than part of the terminal tergite to at least three complete abdominal tergites; not truncate; rather soft. Scutellary striole absent. Elytra non-glabrous; with epipleura (broad at the base). Wings well developed, or absent or much reduced. Exposed abdominal sternites 6–9; all articulated and movable. Abdominal segment 8 with apparently functional spiracles, or apparently without functional spiracles.
Adult habitat, ecology. Not predacious (not feeding at all?).
Larvae. Larvae free-living and predacious (on snails and worms). The larvae brown and elongate, tapered fore and aft, with six short legs; with a small head borne beneath the prothorax, with 3-segmented antennae, one ocellus on either side and equipped with channelled mandibles associated with paralyzing and extra-oral digestion of prey.
Classification. Suborder Polyphaga; Infraorder Elateriformia; Superfamily Cantharoidea.
Worldwide and British representation. About 2000 species worldwide (temperate and tropical). 2 species in Britain; genera in Britain 2; Lampyris, Phosphaenus. E.g., Lampyris noctiluca.
General comments. The adult females of Lampyris and both sexes of Phosphaenus are famously luminescent from their distal abdominal sternites.
Illustrations. • Lampyris noctiluca (Glow Worm): B. Ent. 698. • Lampyris noctiluca: B. Ent. 698, legend+text. • Lampyris noctiluca: B. Ent. 698, text cont.. • Lampyris noctiluca and Phosphaenus hemipterus (with Cantharidae): Fowler 4, 111 (1890). • Fowler 4, 111 (1890): original legend. • Lampyris noctiluca, male and female (Janson 190, 191).
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: the families of Coleoptera. Version: 2nd January 2012. http://delta-intkey.com’.
