British insects: the families of Coleoptera
British insects: the families of Coleoptera | |
~Ciidae, Cioidae.
Tree-fungus beetles.
General appearance. 1.2–3 mm long. Body length/maximum body width 1.38–2.77. Elytral length/pronotal length 1.2–3. 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 elongate; cylindric; not necked; somewhat waisted. 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 prognathous. Inclination of the head slight. Eyes strongly protuberant; bristly, or without bristles; finely facetted. Antennae short; 8–11 segmented. Antennal scape not swollen. Antennae clubbed. Antennal clubs 3 segmented (elongate, the segments obviously separated). Antennal insertions visible from above, or hidden from above; not in fossae. Mandibular prosthecae absent. Prothorax about as long as wide. Pronotal length/maximum pronotal width 0.55–0.95. 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 closed behind. Hind coxae not shaped posteriorly to receive the femur. Tarsal segmentation formula 4, 4, 4, or 3, 3, 3. The tarsi without bilobed segments; without ‘hidden’ segments. Front tarsi with as many segments as the mid-tarsi; 3-segmented, or 4-segmented (with segments 1–3 short). Mid-leg tarsi 3-segmented, or 4-segmented (with segments 1–3 short); tetramerous, or trimerous. The claws of the mid-leg tarsi not appendaged. The claws of the mid-leg tarsi simple; with an empodium between them (this with no more than two setae), or without an associated empodium. Hind tarsi with as many segments as the mid-tarsi; 3-segmented, or 4-segmented (with segments 1–3 short). Elytral length/maximum width across the elytra 0.88–2.08. Elytra covering most to all of the abdomen; exposing no more than part of the terminal tergite; without striae (punctures randomly distributed, at least over the forward part). Scutellary striole absent. Elytra with epipleura. Elytral epipleura reaching to the tips of the elytra. Wings well developed, or absent or much reduced. Exposed abdominal sternites 5; all articulated and movable, or comprising both fused and movable components; immovably joined when present, 2. Abdominal segment 8 apparently without functional spiracles.
Adult habitat, ecology. Not predacious; mycetophagous; in rotting wood, under bark, and associated with fungi (commonly in bracket fungi in trees).
Larvae. Larvae not predacious; mycetophagous; in rotting wood, in or under bark, and in fungi (cf. adults).
Classification. Suborder Polyphaga; Infraorder Cucujiformia; Superfamily Tenebrionoidea.
Worldwide and British representation. Genera about 50 (? - mostly in warm regions). 22 species in Britain; genera in Britain 4; Cis, Octotemnus, Rhopalodontus, Sulcacis. E.g., Cis bidentatus (Double-horned Cis).
General comments. Minute, cylindrical beetles, somewhat resembling Curculionidae-Scolitinae, but the three-segmented antennal club is les compact.
Illustrations. • Cis bidentatus (Double-horned Cis: B. Ent. 402). • Cis bidentatus (details, B. Ent. 402). • Cis bidentatus: B. Ent. 402, legend+text. • Cis bidentatus: B. Ent. 402, legend cont.. • Cis (5 spp.), Ennearthron, Octotemnus, Sulcacis (with unrelated taxa): Fowler 4, 119 (1890). • Fowler 4, 119 (1890): original legend.. • Cis dentatus, with Cerambycidae etc.: Fowler Suppl. 16, 1913. • Fowler Suppl. 16, 1913: original legend..
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’.
