British Insects: the Families of Coleoptera
British Insects: the Families of Coleoptera |
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Including Thorictidae, Thylodriidae, Thylodriadidae.
Museum Beetles.
General appearance. 1.5–8 mm long. Body length/maximum body width 1.42–3. Elytral length/pronotal length 1.72–5.33. 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 (generally robust); not necked; not waisted to somewhat waisted. Upper surfaces of body glabrous or subglabrous, or non-glabrous; exhibiting stiff, erect, dark bristles, or not bristly; exhibiting scales or scale-like setae, or with neither scales nor scale-like setae.
Detailed morphology. Inclination of the head slight to very strong. Eyes strongly protuberant, or not strongly protuberant; bristly, or without bristles. Ocelli present, or absent; when present, solitary (median). Antennae very short to short; 9 segmented, or 11 segmented. Antennal scape not swollen. Antennae clubbed. Antennal clubs 3–5 segmented; preceded by a cupule, or without a cupule. Antennal insertions visible from above.
Prothorax shorter than wide. Pronotal length/maximum pronotal width 0.37–1. 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; with a tiny penultimate segment hidden by lobing of the one proximal to it (hind tarsi, sometimes), or with a tiny basal segment that is hard to detect, or 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 1–2.35. Elytra covering most of the abdomen; exposing no more than part of the terminal tergite, or at least three complete abdominal tergites. Scutellary striole absent. Elytra non-glabrous (often covered with fine hair or scales), or glabrous. Wings well developed, or absent or much reduced.
Visible abdominal sternites 5–9; immovably joined 0, or 2. Abdominal segment 8 with apparently functional spiracles.
Habitat, ecology. Land-dwellers; not predacious; in living vegetation (often on flowers).
Larvae. Larvae not predacious; feeding on dried animal remains (on material of high protein content, e.g. skins, bacon, etc.); in carrion and in stored plant products (and and other human foodstuffs).
Classification. Suborder Polyphaga; Superfamily Dermestoidea.
British representation. Genera 9; 30 species. E.g., Aspidophorus orbiculatus (Orbicular Dermestes); Ctesias serra (Toothed-horn Megatoma); Dermestes lardarius.
Illustrations. • Attagenus trifasciatus (Adventive: B. Ent. 247). • Ctesias serra (Toothed-horn Megatoma: B. Ent. 244). • Dermestes lardarius (Janson 177).
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’.
