British insects: the families of Coleoptera
British insects: the families of Coleoptera | |
Stag-beetles.
General appearance. 10–66 mm long. Body length/maximum body width 1.3–2.85. Elytral length/pronotal length 1.65–3.2. 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, or distinctly narrower than greatest elytral width. Beetles round to elongate-oval; not necked; conspicuously waisted. Upper surfaces of body glabrous or subglabrous, or non-glabrous; exhibiting stiff, erect, dark bristles, or not bristly; exhibiting scales or scale-like setae, or with neither scales nor scale-like setae.
Detailed morphology. Beetles prognathous. Inclination of the head slight to strong. Eyes strongly protuberant, or not strongly protuberant; without bristles; finely facetted. Antennae short to about half the insect's head to tail length; strongly asymmetric; conspicuously elbowed; 8 segmented, or 10 segmented; with the scape much-elongated; clubbed. Antennal clubs lamellate; preceded by a cupule, or without a cupule. Antennal insertions hidden from above; not in fossae. Mandibular prosthecae well developed to absent. Prothorax shorter than wide to about as long as wide. Pronotal length/maximum pronotal width 0.43–0.9. Prothorax at its widest not markedly narrower than the adjoining part of the abdomen; having the front corners produced, or with serrated sides, or with neither produced front corners nor serrated sides. Prothorax without notopleural sutures. Metaventrite without a transverse groove. Tarsal segmentation formula 5, 5, 5. The tarsi without 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; with an empodium between them (this sometimes with three or more setae), or without an associated empodium. Hind tarsi with as many segments as the mid-tarsi; 5-segmented. Elytral length/maximum width across the elytra 0.87–1.95. Elytra exposing no more than part of the terminal tergite; glossy; striate, or without striae (usually). Scutellary striole absent. Wings well developed, or absent or much reduced. Exposed abdominal sternites 5–6; all articulated and movable, or comprising both fused and movable components; immovably joined when present, 2. Abdominal segment 8 with apparently functional spiracles, or apparently without functional spiracles.
Adult habitat, ecology. Not predacious; in rotting wood.
Larvae. Larvae not predacious; consuming decaying plant material; in rotting wood.
Classification. Suborder Polyphaga; Infraorder Scarabaeiformia; Superfamily Scarabaeoidea.
Worldwide and British representation. About 1200 species worldwide; genera about 130. 4 species in Britain; genera in Britain 4; Dorcus, Lucanus, Platycerus, Synodendron. E.g., Lucanus cervus (Stag Beetle); Platycerus caraboides (Blue Lucanus: Lucanidae, extinct?); Synodendron cylindricum (Cylindrical Lucanus).
General comments. The adults of some species with enormous mandibles. Tarsi sometimes with fewer than three segments in non-British species.
Illustrations. • Lucanus cervus (Stag Beetle: B. Ent. 490). • Lucanus cervus (detail: B. Ent. 490). • Lucanus cervus: B. Ent. 490, legend+text. • Lucanus cervus: B. Ent. 490, text cont.. • Platycerus caraboides (Blue Lucanus, extinct in Britain): B. Ent. 274. • Platycerus caraboides: B. Ent. 274, legend+text. • Platycerus caraboides: B. Ent. 274, text cont.. • Synodendron cylindricum (Cylindrical Lucanus: B. Ent. 478). • Synodendron cylindricum: B. Ent. 478, legend+text. • Synodendron cylindricum: B. Ent. 478, text cont.. • Dorcus papallelipipedus, Lucanus cervus, Platycerus caraboides, Sinodendron cylindricum: Fowler 4, 99 (1890). • Fowler 4, 99 (1890): original legend..
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’.
