British insects: the families of Coleoptera
British insects: the families of Coleoptera |
|
= Bostrichidae; including Psoidae.
Wood-borers, Augur beetles.
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. Hind coxae not shaped posteriorly to receive the femur. Tarsal segmentation formula 5, 5, 5. The tarsi without bilobed segments; of British species, 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. Hind tarsi with as many segments as the mid-tarsi; 5-segmented. 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. Exposed abdominal sternites 5 (the first hardly longer than the second or the third); all articulated and movable, or comprising both fused and movable components; immovably joined when present, 2. Abdominal segment 8 with apparently functional spiracles.
Adult habitat, ecology. Not predacious; in rotting wood.
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; Infraorder Bostrichiformia; Superfamily Bostrichoidea.
Worldwide and British representation. About 700 species worldwide. 3 species in Britain; genera in Britain 3; Bostrichus, Rhyzopertha, Stephanopachys. E.g., Bostrichus capucinus (Capuchin Beetle: extinct?).
General comments. The tarsi more variable in non-British species.
Illustrations. • Bostrichus capucinus (Capuchin beetle): B. Ent. 271. • Bostrichus capucinus: B. Ent. 271, legend+text. • Bostrichus capucinus: B. Ent. 271, text cont.. • Bostrichus capucinus and Rhizopertha pusilla (= ?, with Cisidae, etc.): Fowler 4, 119 (1890). • Fowler 4, 119 (1890): original legend.. • Stephanopachys substriatus (with Anobiidae): Fowler 4, 118 (1890). • Fowler 4, 118 (1890): original legend. • Dinoderus minutus (Bamboo borer, with unrelated taxa). • Fowler Suppl. 16, 1913: 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’.
