British Insects: the Families of Coleoptera
British Insects: the Families of Coleoptera |
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= Limnebiidae.
Water-beetles.
General appearance. 1.1–1.7 mm long. Body length/maximum body width 1.6–2.57. Elytral length/pronotal length 1.77–3.62. 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 elongate; not necked; conspicuously waisted. Upper surfaces of body glabrous or subglabrous, or non-glabrous; not bristly; with neither scales nor scale-like setae.
Detailed morphology. Eyes not strongly protuberant; without bristles. Antennae very short to about half the insect's head to tail length; 7–11 segmented; clubbed. Antennal clubs 5 segmented; preceded by a cupule, or without a cupule. Antennal insertions hidden from above.
Pronotal length/maximum pronotal width 0.42–1.05. Prothorax without notopleural sutures. Metaventrite without a transverse groove. The tarsi without bilobed segments; with a tiny basal segment that is hard to detect. Mid-leg tarsi 4-segmented; pentamerous, or tetramerous. 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; not modified for swimming. Tarsal claws simple; without an associated empodium. Elytral length/maximum width across the elytra 1.18–2. Elytra exposing no more than part of the terminal tergite. Scutellary striole absent. Wings well developed, or absent or much reduced; fringed with long hairs on the hind margin, or not fringed.
Visible abdominal sternites 7; immovably joined 0. Abdominal segment 8 with apparently functional spiracles.
Habitat, ecology. Water-beetles; moving in the water by alternate, walking leg movements; in living vegetation (on algae).
Larvae. Larvae non-aquatic (living in wet places, but easily drowned); on living vegetation (on algae).
Classification. Suborder Polyphaga; Superfamily Staphilinoidea.
British representation. Genera 3; 29 species. E.g., Hydraena testacea (Testaceous Hydraena); Ochthebius punctatus (Irish Ochthebius); Ochthebius exsculptus (Gibson's Enicocerus).
Illustrations. • Hydraena testacea (Testaceous Hydraena: B. Ent. 307). • Hydraena testacea (details, B. Ent. 307). • Hydraena testacea: B. Ent. 307, legend+text. • Ochthebius punctatus (Irish Ochthebius: B. Ent. 250). • Ochthebius exsculptus (Gibson's Enicocerus: B. Ent. 291).
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’.
