British Insects: the Families of Coleoptera
British Insects: the Families of Coleoptera |
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~Trogossitidae.
General appearance. 5–7 mm long. Elytral length/pronotal length 2.6–3. Base of prothorax distinctly narrower than the combined elytral bases. Greatest prothoracic width distinctly narrower than greatest elytral width. Beetles round to oval; terrapin-like in shape, with flattened and clear margins to thorax and elytra; dorsally flattened; not necked; conspicuously 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. Eyes strongly protuberant, or not strongly protuberant; bristly, or without bristles. Antennae very short to short; 11 segmented; clubbed. Antennal clubs loosely 3 segmented. Antennal insertions visible from above, or hidden from above (?).
Pronotal length/maximum pronotal width 0.5–0.7. Prothorax without notopleural sutures. Metaventrite without a transverse groove. The tarsi exhibiting bilobed segments, or without bilobed segments; with a tiny basal segment that is hard to detect, or without ‘hidden’ segments (?). Mid-leg tarsi 4-segmented, or 5-segmented; pentamerous, or tetramerous. Claws of the mid-leg tarsi not appendaged. Front tarsi with as many segments as the mid-tarsi; 4-segmented, or 5-segmented. Hind tarsi with as many segments as the mid-tarsi; 4-segmented, or 5-segmented. Scutellary striole absent. Wings well developed.
Abdominal segment 8 apparently without functional spiracles (?).
Habitat, ecology. Mycetophagous (associated with bracket fungi); under bark.
Larvae. Larvae not predacious; mycetophagous (found in bracket fungi).
Classification. Suborder Polyphaga; Superfamily Cleroidea.
British representation. Genera 2; 2 species. E.g., Thymalus limbatus (Rust-coloured Thymalus).
Illustrations. • Thymalus limbatus (Rust-coloured Thymalus: B. Ent. 039). • Thymalus limbatus (details, B. Ent. 039). • Thymalus limbatus: B. Ent. 039, legend+text.
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’.
