British Insects: the Families of Coleoptera
British Insects: the Families of Coleoptera |
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~Curculionidae.
Bark-beetles.
General appearance. 1.2–6 mm long. Body length/maximum body width 1.27–3.15. Elytral length/pronotal length 1.2–2.43. 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-oval to elongate; cylindric; not necked; conspicuously waisted. 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. Beetles without a rostrum. Inclination of the head strong. Eyes strongly protuberant, or not strongly protuberant; without bristles; finely facetted. Antennae very short to short; conspicuously elbowed; 3–11 segmented; with the scape much-elongated; clubbed (the club elongated). Antennal clubs 1–3 segmented. Antennal insertions hidden from above; not in fossae. Mandibular prosthecae absent.
Pronotal length/maximum pronotal width 0.49–1.35. Prothorax without notopleural sutures. Metaventrite without a transverse groove. The tarsi exhibiting bilobed segments; with a tiny penultimate segment hidden by lobing of the one proximal to it, or without ‘hidden’ segments (the fourth segment small, but generally visible; the basal segment shorter than the others together). Mid-leg tarsi 5-segmented; pentamerous, or pseudotetramerous. 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 without an associated empodium. Elytral length/maximum width across the elytra 0.7–1.9. Elytra exposing no more than part of the terminal tergite. Scutellary striole absent. Wings well developed, or absent or much reduced.
Visible abdominal sternites 5; immovably joined 2. Abdominal segment 8 apparently without functional spiracles.
Habitat, ecology. Under bark (some serious forest pests).
General comments. The antennae with short middle segments, consisting mainly of the elongated scape and club.
Larvae. Larvae in or under bark.
Classification. Suborder Polyphaga; Superfamily Curculionoidea.
British representation. Genera 27; 57 species. E.g., Hylesinus oleiperda(Rough Hylesinus); Pteleobius vittatus; Scolytus scloytus (Elm Bark Beetle); Trypodendron lineatum.
Illustrations. • Scolytus scolytus (Elm Bark Beetle: B. Ent. 043). • Scolytus scolytus (details, B. Ent. 043). • Scolytus scolytus: B. Ent. 043, legend+text. • Scolytus scolytus: B. Ent. 043, text cont.. • Tomicus piniperda (Pine-feeding Hylesinus: B. Ent. 104). • Tomicus piniperda (details, B. Ent. 104). • Tomicus piniperda: B. Ent. 104, legend+text. • Tomicus piniperda: B. Ent. 104, text cont.. • Hylesinus oleiperda (Rough Hylesinus: B. Ent. 522). • Acrantus vittatus, Xyloterus lineatum (Rye & Fowler XII6).
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: 18th September 2008. http://delta-intkey.com’.
