British Insects: the Families of Coleoptera |
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Including Calyptomeridae.
General appearance. 0.8–1.8 mm long. Body length/maximum body width 1.1–1.55. Elytral length/pronotal length 0.85–3.6. 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 broadly oval; dorsally more or less convex to dorsally strongly convex; not necked; not waisted. Upper surfaces of body glabrous or subglabrous, or non-glabrous; not bristly; with neither scales nor scale-like setae. Beetles rolling into a ball when alarmed (sometimes), or not conglobulating.
Detailed morphology. Inclination of the head slight. Eyes strongly protuberant, or not strongly protuberant; without bristles; coarsely facetted. Antennae short; 8–10 segmented; clubbed. Antennal clubs 2 segmented. Antennal insertions visible from above, or hidden from above.
Pronotal length/maximum pronotal width 0.3–0.5. Prothorax without notopleural sutures. Metaventrite without a transverse groove. The tarsi without bilobed segments; without hidden segments. Mid-leg tarsi 4-segmented (usually, cf. Imms (1957), Britton 1970, Lawrence et al. 1999); tetramerous (sometimes trimerous in non-British species). Claws of the mid-leg tarsi not appendaged. Front tarsi with as many segments as the mid-tarsi; 4-segmented. Hind tarsi with as many segments as the mid-tarsi; 4-segmented. Tarsal claws simple. Elytral length/maximum width across the elytra 0.85–1.2. Elytra covering most of the abdomen; exposing no more than part of the terminal tergite. Scutellary striole absent. Elytra non-glabrous (sparsely setose). Wings well developed; fringed with long hairs on the hind margin, or not fringed.
Visible abdominal sternites 5–6; immovably joined 0. Abdominal segment 8 with apparently functional spiracles, or apparently without functional spiracles.
Habitat, ecology. Not predacious (?); in decaying plant material.
General comments. Unwin gives tarsi as 5,5,5, seemingly in error: the other sources give 4,4,4, with Lawrence et al. also allowing 3,3,3.
Larvae. Larvae not predacious (?); mycetophagous (?).
Classification. Suborder Polyphaga; Superfamily Eucinetoidea.
British representation. Genera 2; 9 species.
Illustrations. • Calyptomerus, Clambus (from Joy).
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’.