British insects: the families of Coleoptera
Fungus-feeders, Silken Fungus Beetles.
General appearance. 1.3–11 mm long. Body length/maximum body width 1.48–2.95. Elytral length/pronotal length 1.48–3.6. 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-oval to elongate; not necked; somewhat waisted. Upper surfaces of body glabrous or subglabrous, or non-glabrous; not bristly; with neither scales nor scale-like setae.
Detailed morphology. Beetles without a rostrum; prognathous. Inclination of the head slight. Eyes strongly protuberant, or not strongly protuberant; bristly, or without bristles. Antennae short to about half the insect's head to tail length; (10–)11 segmented. Antennal scape swollen, or not swollen (?). Antennae clubbed. Antennal clubs 3 segmented (loosely). Antennal insertions visible from above, or hidden from above; not in fossae. Prothorax shorter than wide. Pronotal length/maximum pronotal width 0.4–1.5. Prothorax at its widest not markedly narrower than the adjoining part of the abdomen; having the front corners produced, or with serrated sides, or with neither produced front corners nor serrated sides. Prothorax without notopleural sutures. Hind corners of the thorax not extended rearwards into sharp points. Metaventrite without a transverse groove. The foreleg coxal cavities open behind. The mid-leg cavities closed laterally. Hind-leg coxae not markedly extended laterally; not shaped posteriorly to receive the femur. Tarsal segmentation formula 5, 5, 5, or 5, 5, 4, or 4, 4, 4. The tarsi exhibiting bilobed segments; with a tiny penultimate segment hidden by distal lobing of the fourth and fused to the fifth, 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 pseudotetramerous, or tetramerous. The claws of the mid-leg tarsi not appendaged. The claws of the mid-leg tarsi simple. Hind tarsi with as many segments as the mid-tarsi, or with one segment fewer than the mid-tarsi; 4-segmented (sometimes, in males), or 5-segmented. Elytral length/maximum width across the elytra 1–2.1. Elytra covering most to all of the abdomen; exposing no more than part of the terminal tergite. Scutellary striole absent. Elytra with epipleura. Elytral epipleura falling short of the elytral tips (limited to the basal half). Wings well developed, or absent or much reduced. Exposed abdominal sternites 5; all articulated and moveable. Abdominal segment 8 apparently without functional spiracles.
Adult habitat, ecology. In decaying plant material, in rotting wood, in dried plant material, associated with fungi, and on shed fur or feathers; consuming decaying plant material and mycetophagous (generally feeding on fungal material, whatever the habitat; commonly in houses, on moulds associated with damp plaster).
Larvae. Mature larvae minute (less than 3 mm long), or small to medium-sized. The larvae elongate and more or less parallel-sided. Body circular in cross-section, or somewhat flattened. Vestiture restricted to fine hairs or setae. The larvae dorsally heavily pigmented or sclerotized, or dorsally only very lightly pigmented or sclerotized (Cryptogasterus only); ventrally only very lightly pigmented. The antennae 3 segmented. Stemmata present, or absent; on either side of the larval head when present, 1–2, or 5. The frontoclypeal suture between frons and clypeus indistinct or absent. The labrum and head capsule separated by a complete suture, or partly fused, with an incomplete suture. Apices of the mandibles bilobed or bidentate. The maxillary palps 3 segmented. The labium with a short ligula between the palps (mostly), or with a ligula at least as long as the palps (Cryptogasterus). Labial palps present and segmented; 1 segmented, or 2 segmented. Mesothoracic legs present and segmented; 5 segmented; with 1 moveable claw. Visible abdominal segments 10. Tergum 9 of the abdomen entirely dorsal, or extending to the underside. The abdomen having functional spiracles on anterior segments (these annular or annular-biforous); without spiracular tubes. The abdominal apex without a respiratory chamber. Abdominal tergum 8 without amature. The last abdominal segment with cerci (mostly), or without cerci (some Atomariinae).
Larvae in decaying plant material, or in rotting wood, or in dried plant material, or under bark, or associated with fungi, or in shed fur or feathers, or associated with flowers (some Telmatophilus species being found in flowers of aquatic monocots); mostly mycetophagous (feeding on fungal material, whatever the habitat; commonly in houses, on moulds associated with damp plaster).
The larvae subcylindrical, whitish, with ocelli and 3-segmented antennae, the abdomen 10 segmented with the tenth constituting a proleg.
Classification. Suborder Polyphaga; Superfamily Cucujoidea.
Worldwide and British representation. About 800 species worldwide. 110 species in Britain; genera in Britain 10; Antherophagus, Atomaria, Coenoscelis, Cryptophagus, Ephistemus, Henoticus, Micrambe, Ootypus, Paramecosoma, Telmatophilus. E.g., Antherophagus pallens (Punctured Antherophagus); Cryptophagus populi (Dark Cryptophagus Fungus-feeder); Paramecosoma melanocephalum.
General comments. Beetles very small, pubescent.
Illustrations. • Antherophagus pallens (Punctured Antherophagus: B. Ent. 546). • Antherophagus pallens: B. Ent. 546, legend+text. • Antherophagus pallens: B. Ent. 546, text cont.. • Cryptophagus populi (Dark Fungus-feeder: B. Ent. 160). • Cryptophagus populi (details, B. Ent. 160). • Cryptophagus populi: B. Ent. 160, legend+text. • Cryptophagus populi: B. Ent. 160, text cont.. • Paramecosoma melanocephalum: B. Ent. 606. • Paramecosoma melanocephalum: B. Ent. 606, legend+text. • Paramecosoma melanocephalum: B. Ent. 606, text cont.. • Antherophagus, Cryptophagus (8 spp.), Micrambe, Paramecosoma, Telmatophilus: Fowler 3, 94 (1889). • Fowler 3, 94 (1889): original legend.. • Atomaria (8spp.), Caenoscelis, Ephistemus (with Mycetophagidae and Scaphiidae): Fowler 3, 95 (1889). • Fowler 3, 95 (1889): original legend.. • Henoticus serratus, Micrambe abietis and M. bimaculatus, with Dryopidae, etc.: Fowler 6, 14 (1913). • Fowler 6, 14 (1913): original legend.. • Telmatophilus sparganii, with Cucujidae, Silvanidae etc.: Fowler 3, 93 (1889). • Fowler 3, 93 (1889): original legend.. • Paramecosoma melanocephalum (Janson 134).
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: 25th July 2012. http://delta-intkey.com’.