British Insects: the Families of Coleoptera
British Insects: the Families of Coleoptera |
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= Bostrichidae; including Psoidae.
Wood-borers.
General appearance. 2.5–9 mm long. Body length/maximum body width 2.33–3.72. Elytral length/pronotal length 1.8–3.9. Base of prothorax not or scarcely narrower than the combined elytral bases, or distinctly 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 elongate; cylindric; not necked; conspicuously waisted; black or brown. Upper surfaces of body glabrous or subglabrous, or non-glabrous; not bristly; exhibiting scales or scale-like setae, or with neither scales nor scale-like setae.
Detailed morphology. The head covered by the thorax. Eyes strongly protuberant; without bristles; finely facetted. Antennae short; not elbowed; 8–11 segmented. Antennal scape not swollen. Antennae clubbed. Antennal clubs 2 segmented, or 4 segmented (loose). Antennal insertions hidden from above. Mandibular prosthecae present but reduced, or absent.
Pronotal length/maximum pronotal width 0.68–1.35. Prothorax hooded and concealing the head, its front covered with large bumps. Prothorax without notopleural sutures. Metaventrite without a transverse groove. The tarsi without bilobed segments; of British species, without ‘hidden’ segments. Mid-leg tarsi 5-segmented; pentamerous. Claws of the mid-leg tarsi not appendaged. Front tarsi with as many segments as the mid-tarsi; 5-segmented. Hind tarsi with as many segments as the mid-tarsi; 5-segmented. Tarsal claws simple. Elytral length/maximum width across the elytra 1.5–2.85. Elytra exposing no more than part of the terminal tergite; hard (strongly sclerotized); often spiny (distally). Scutellary striole present, or absent. Wings well developed.
Visible abdominal sternites 5; immovably joined 0, or 2. Abdominal segment 8 with apparently functional spiracles.
Habitat, ecology. Not predacious; in rotting wood.
General comments. The tarsi more variable in non-British species.
Larvae. Larvae not predacious; boring into living wood and boring into dead wood; tunnelling in moribund and newly fallen timber, but not in seasoned wood.
Classification. Suborder Polyphaga; Superfamily Bostrichoidea.
British representation. Genera 3; 3 species. E.g., Bostrichus capucinus (Capuchin Beetle: extinct?).
Illustrations. • Bostrichus capucinus (Capuchin beetle: B. Ent. 271). • Bostrichus capucinus (B. Ent. 271, legend+text).
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: 9th June 2008. http://delta-intkey.com’.
