British Insects: the Families of Coleoptera
British Insects: the Families of Coleoptera |
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~Anobiidae.
Spider-beetles.
General appearance. 2–5.5 mm long. Body length/maximum body width 1.45–4.63. Elytral length/pronotal length 1.65–3.2. 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 oval to elongate; not necked; conspicuously waisted; conspicuously long-legged; brown to black. Upper surfaces of body glabrous or subglabrous, or non-glabrous; exhibiting stiff, erect, dark bristles, or not bristly; with neither scales nor scale-like setae, or exhibiting scales or scale-like setae.
Detailed morphology. Beetles without a rostrum. Eyes not strongly protuberant; without bristles. Antennae short to long, but not exceeding the insect’s head to tail length; 8–9 segmented, or 11 segmented. Antennal scape not swollen. Antennae filiform. Antennal insertions visible from above. Mandibular prosthecae absent.
Prothorax shorter than wide. Pronotal length/maximum pronotal width 0.6–1.42. Prothorax at its widest not markedly narrower than the adjoining part of the abdomen. Prothorax without notopleural sutures. Metaventrite without a transverse groove. The tarsi without bilobed segments; 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, or with one segment fewer than the mid-tarsi; 4-segmented, or 5-segmented. Tarsal claws simple. Elytral length/maximum width across the elytra 1.03–2.63. Elytra covering most of the abdomen; exposing no more than part of the terminal tergite. Scutellary striole present, or absent. Wings well developed, or absent or much reduced.
Visible abdominal sternites 5; immovably joined 3. Abdominal segment 8 with apparently functional spiracles, or apparently without functional spiracles.
Habitat, ecology. Land-dwellers; not predacious; in decaying plant material, in rotting wood, in dried plant material, on shed fur or feathers, and in stored plant products (mainly in dry plant or animal material).
General comments. The antennal insertions close together, separated by less than the length of the scape.
Larvae. Larvae not predacious; necrophagous, feeding on dried animal remains, consuming decaying plant material, and eating dried plant material or stored plant products; in decaying plant material, in rotting wood, in dried plant material, in shed fur or feathers, and in stored plant products (mainly in dry plant or animal material; not borers).
Classification. Suborder Polyphaga; Superfamily Bostrichoidea.
British representation. Genera 7; 21 species. E.g., Gibbium psylloides (Northern Ptinus); Mezium affine (Shining Ptinus); Ptinus sexpunctatus.
Illustrations. • Gibbium psylloides (Northern Ptinus: B. Ent. 342). • Gibbium psylloides (details, B. Ent. 342). • Gibbium psylloides: B. Ent. 342, legend+text. • Mezium affine (Shining Ptinus: B. Ent. 232). • Ptinus sexpunctatus (Janson 166).
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’.
