British insects: the families of Coleoptera
British insects: the families of Coleoptera |
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= Lymexylonidae; including Atractoceridae.
Timber-borers, Ship-timber beetles.
General appearance. 7–18 mm long. Body length/maximum body width 4.05–12.2. Elytral length/pronotal length 1.5–5.25. 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 to slender; conspicuously necked to not necked; somewhat waisted. Upper surfaces of body non-glabrous; not bristly; with neither scales nor scale-like setae.
Detailed morphology. Eyes strongly protuberant; without bristles; finely facetted. Antennae short; 11 segmented. Antennal scape not swollen. Antennae filiform (or fusiform), or serrate. Antennal insertions visible from above, or hidden from above. Mandibular prosthecae well developed, or absent. Prothorax longer than wide. Pronotal length/maximum pronotal width 0.75–1.5. Prothorax at its widest not markedly narrower than the adjoining part of the abdomen. 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). Hind tarsi with as many segments as the mid-tarsi; 5-segmented. Elytral length/maximum width across the elytra 1.45–4.67. Elytra individually distinctly tapered to their apices to not individually tapered; not meeting along the full length of the mid-line (at least, narrowly separated towards their tips); fairly short, exposing several terminal abdominal tergites (in the British representatives); exposing no more than part of the terminal tergite to at least three complete abdominal tergites (the abdominal tip pointed); truncate; soft. Scutellary striole absent. Elytra non-glabrous. Wings well developed. Exposed abdominal sternites 5–7; all articulated and movable. Abdominal segment 8 apparently without functional spiracles.
Adult habitat, ecology. Not predacious; boring into living wood.
Larvae. Larvae not predacious; mycetophagous (in tunnels bored in the wood of weakened trees); in wood. The larvae boring into living and decaying wood; elongate, thin, cylindrical with short but well developed legs, prognathous with 3-segmented antennae, the sclerotized pronotum partially hooding the head.
Classification. Suborder Polyphaga; Superfamily Lymexyloidea.
Worldwide and British representation. About 40 species worldwide; genera 7. 2 species in Britain; genera in Britain 2; Hylecoetus, Lymexylon. E.g., H. dermestoides; L. navale (Windsor Wood-borer).
General comments. Elongate, soft bodied beetles. Worldwide variation ranges from forms with elytra so short that they do not reach the abdomen, to others in which they cover all except the terminal tergite.
Illustrations. • Hylecoetus dermestoides: B. Ent. 654. • Hylecoetus dermestoides: B. Ent. 654, legend+text. • Hylecoetus dermestoides: B. Ent. 654, text cont.. • Hylecoetus dermestoides (Rye & Fowler IX6). • Hylecoetus dermestoides (Janson 162). • Lymexylon navale (Windsor Wood-borer: B. Ent. 382). • Lymexylon navale (details, B. Ent. 382). • Lymexylon navale: B. Ent. 382, legend+text. • Lymexylon navale: B. Ent. 382, text cont.. • Hylecoetus dermestoides and Lymexylon navale (with Ptinidae, Cleridae, etc.): Fowler 4, 116 (1890). • Fowler 4, 116 (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’.
