British insects: the families of Coleoptera
British insects: the families of Coleoptera | |
~Trogossitidae-Peltinae.
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. Tarsal segmentation formula 5, 5, 5, or 4, 4, 4. The tarsi exhibiting bilobed segments, or without bilobed segments; with a tiny basal segment that is hard to detect, or without ‘hidden’ segments (?). Front tarsi with as many segments as the mid-tarsi; 4-segmented, or 5-segmented. Mid-leg tarsi 4-segmented, or 5-segmented; pentamerous, or tetramerous. The claws of the mid-leg tarsi not appendaged. Hind tarsi with as many segments as the mid-tarsi; 4-segmented, or 5-segmented. Scutellary striole absent. Wings well developed. Exposed abdominal sternites 5, or 6 (?). Abdominal segment 8 apparently without functional spiracles (?).
Adult habitat, ecology. Presumably not predacious; mycetophagous (associated with bracket fungi); under bark.
Larvae. Larvae not predacious; mycetophagous (found in bracket fungi).
Classification. Suborder Polyphaga; Infraorder Cucujiformia; Superfamily Cleroidea.
Worldwide and British representation. About 50 species worldwide; genera about 20. 2 species in Britain; genera in Britain 2; Ostoma, Thymalus. 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. • Thymalus limbatus: B. Ent. 039, text cont..
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’.
