British Insects: the Families of Coleoptera
British Insects: the Families of Coleoptera |
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Including Dacnidae.
General appearance. 2.5–7 mm long. Body length/maximum body width 1.15–2.87. Elytral length/pronotal length 2–5.75. 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 oval to elongate; convex beneath; not necked; not waisted to somewhat waisted; often with a bright yellow and black pattern, or metallic colour; exhibiting bright ‘warning colours’, or without ‘warning colouration’. 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.
Detailed morphology. Beetles without a rostrum; prognathous. Inclination of the head slight. Eyes strongly protuberant, or not strongly protuberant; bristly, or without bristles. Antennae short; 11 segmented. Antennal scape not swollen. Antennae clubbed. Antennal clubs 3 segmented (flattened). Antennal insertions visible from above, or hidden from above; not in fossae. Mandibular prosthecae well developed, or absent.
Prothorax shorter than wide. Pronotal length/maximum pronotal width 0.25–0.97. Prothorax at its widest not markedly narrower than the adjoining part of the abdomen. Prothorax without notopleural sutures. Metaventrite without a transverse groove. Fore coxal cavites open behind. The tarsi exhibiting bilobed segments; with a tiny penultimate segment hidden by lobing of the one proximal to it, or without ‘hidden’ segments (but the fourth segment usually small). 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, or with one segment fewer than the mid-tarsi; 4-segmented, or 5-segmented. Tarsal claws simple; without an associated empodium. Elytral length/maximum width across the elytra 1–2.2. Elytra covering most of the abdomen; exposing no more than part of the terminal tergite. Scutellary striole present, or absent. Elytra non-glabrous, or glabrous; with epipleura. Elytral epipleura reaching to the tips of the elytra. Wings well developed, or absent or much reduced.
Visible abdominal sternites 5; immovably joined 0, or 2. Abdominal segment 8 apparently without functional spiracles.
Habitat, ecology. Land-dwellers; not predacious; under bark and associated with fungi (on trees).
General comments. The tibiae flattened and expanded.
Larvae. Larvae not predacious; mycetophagous (on fleshy fungi); in or under bark and in fungi (on trees).
Classification. Suborder Polyphaga; Superfamily Cucujoidea.
British representation. Genera 3; 7 species. E.g., Tritoma bipustulata.
Illustrations. • Tritoma bipustulata (Double-spotted Tritoma: B. Ent. 498). • Tritoma bipustulata (details, B. Ent. 498). • Tritoma bipustula: B. Ent. 498, legend+text. • Tritoma bipustulata (Rye & Fowler XV4).
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’.
