Insects of Britain and Ireland: the families of Coleoptera
General appearance. 2.3–2.6 mm long. Body length/maximum body width 1.9–2.3. Elytral length/pronotal length 3.55–3.8. 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; dorsally somewhat convex, or dorsally strongly convex; conspicuously necked to not necked; conspicuously waisted; thorax black, elytra with dark markings. Upper surfaces of body non-glabrous; not bristly; with neither scales nor scale-like setae.
Detailed morphology. Beetles without a rostrum. Eyes strongly protuberant; without bristles; finely facetted. The labrum at least partly visible in antero-dorsal view; labrum mostly moderately to heavily sclerotized. Mandibles without a mola; with well developed prosthecae. The mandibular apices bidentate or bilobed. The incisor edges of the mandibles with a single tooth. The maxillae with distinct galea and lacinia apically to the palp. The apical segment of the maxillary palps cylindrical to fusiform. The apical segment of the labial palps not expanded apically. Antennae short; 11 segmented; clubbed. Antennal insertions visible from above.
Cervical sclerites present. Pronotal length/maximum pronotal width 0.56–0.6. The pronotum with lateral keels (pronotal carinae); keels complete. Prothorax without notopleural sutures. Scutellum conspicuous; not elevated; anteriorly simple; posteriorly broadly rounded or obtusely angulate, or truncate. The prosternal process complete; falling short of the mesoventrite to slightly overlapping the mesoventrite. Metaventrite without a transverse groove. The fore-leg coxae countersunk in procoxal cavities. The fore-leg coxal cavities open behind externally; broadly open; narrowly separated; strongly transverse; without lateral extensions; internally open. The mid-leg coxae countersunk in mesocoxal cavities; separated by less than the shortest diameter of the cavity. The mid-leg coxal cavities narrowly separated; not or scarcely oblique; open laterally. Hind-leg coxae contiguous or narrowly separated; extending laterally to meet the elytra. Tarsal segmentation formula 5, 5, 5. The tarsi without bilobed segments; without hidden segments. Front tarsi with as many segments as the mid-tarsi; 5-segmented. Mid-leg tarsi 5-segmented; pentamerous; the penultimate segment not distinctly shorter than the antepenultimate one. 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; 5-segmented.
Elytral length/maximum width across the elytra 1.5–1.85. Elytra covering most to all of the abdomen; exposing no more than part of the terminal tergite; non-glabrous (slightly hairy). Elytra apunctate, irregularly punctate, or each with fewer than 6 longitudinal lines of punctures or impressed striae. Scutellary striole absent. Wings well developed, or absent or much reduced. Wings with an anal lobe. Wings without a medial fleck. Abdominal sternites 5; all articulated and moveable. Abdominal segment 8 apparently without functional spiracles. The male external genitalia cucujiform.
Adult habitat, ecology. Land-dwellers; on living vegetation and on lichens (e.g., on lichen-covered branches of oak trees), or associated with fungi; mycetophagous (associated with fruit bodies of wood-rotting meruliaceous fungi).
Larvae. Mature larvae small to medium-sized. The larvae elongate and more or less parallel-sided. Body somewhat flattened. Vestiture restricted to fine hairs or setae. The larvae dorsally only very lightly pigmented or sclerotized; ventrally only very lightly pigmented. The antennae 3 segmented. Stemmata present; on either side of the larval head 5, or 6. The frontoclypeal suture between frons and clypeus distinct. The labrum and head capsule separated by a complete suture. Apices of the mandibles bilobed or bidentate. The maxillary palps 3 segmented. The labium with a short ligula between the palps. Labial palps present and segmented; 2 segmented. Mesothoracic legs present and segmented; 5 segmented; with 1 moveable claw. Visible abdominal segments 10. Tergum 9 of the abdomen extending to the underside. The abdomen having functional spiracles on anterior segments (these annular-biforous); without spiracular tubes. The abdominal apex without a respiratory chamber. Abdominal tergum 8 without amature. The last abdominal segment with cerci.
Larvae associated with fungi; mycetophagous (asociated with meruliaceous fungal fruit bodies, cf. the adults).
Classification. Suborder Polyphaga; Infraorder Cucujiformia; Superfamily Cleroidea.
Representation in Britain and Ireland, and worldwide. 1 species worldwide; genera 1. 1 species in Britain (P. edwardsi); genera in Britain 1; Phloiophilus.
General comments. The elytra strongly punctured.
Illustrations. • Phloiophilus edwardsi (from Joy). Phloiophilus edwardsi. • Phloiophilus edwardsi: Fowler 4, 115 (1890).
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. Insects of Britain and Ireland: the families of Coleoptera. Version: 16th May 2016. delta-intkey.com’.