British insects: the families of Coleoptera
British insects: the families of Coleoptera |
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Including Aclopidae, Aphodiidae, Cetoniidae, etc.
Chafers, Dung-beetles, etc.
General appearance. 2.6–20 mm long. Body length/maximum body width 0.9–3.6. Elytral length/pronotal length 0.45–5.55. 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 (the prothorax relatively wide in Aphodiinae). Beetles oval to elongate-oval; dorsally somewhat convex to dorsally strongly convex; not necked; somewhat waisted to conspicuously waisted; exhibiting bright ‘warning colours’, or without ‘warning colouration’. Upper surfaces of body glabrous or subglabrous, or non-glabrous; not bristly; exhibiting scales or scale-like setae, or with neither scales nor scale-like setae.
Detailed morphology. Inclination of the head slight to very strong (the labrum and mouthparts often visible from above, but concealed beneath the fronto-clypeus in Aphodiinae and Scarabaeinae). Eyes strongly protuberant, or not strongly protuberant; bristly (often), or without bristles (e.g., Aphodiinae); finely facetted. Antennae very short to short; strongly asymmetric; conspicuously elbowed, or not elbowed; (7–)9 segmented, or 10 segmented; clubbed. Antennal clubs lamellate; 3–7 segmented. Antennal insertions visible from above, or hidden from above (e.g., in Aphodiinae); not in fossae. Mandibular prosthecae well developed to absent. Prothorax shorter than wide. Pronotal length/maximum pronotal width 0.3–3.08. Prothorax at its widest not markedly narrower than the adjoining part of the abdomen. Prothorax without notopleural sutures. Metaventrite without a transverse groove. Tarsal segmentation formula 0, 5, 5 (occasionally), or 5, 5, 5. The tarsi without bilobed segments; always? without ‘hidden’ segments. The front tarsi present and well developed (e.g., Aphodiinae), or reduced or absent (Scarabaeinae); front tarsi when not reduced or absent (i.e., usually), with as many segments as the mid-tarsi; front tarsi when present, 5-segmented. Mid-leg tarsi 5-segmented; pentamerous. The claws of the mid-leg tarsi not appendaged. The claws of the mid-leg tarsi simple, or one-toothed or bifid, or serrate, denticulate or pectinate; with an empodium between them (this sometimes with three or more setae, but no more than two in Aphodiinae), or without an associated empodium. Hind tarsi with as many segments as the mid-tarsi; 5-segmented (and the hind tibiae with two spurs in Aphodiinae, only one in Scarabaeinae). Elytral length/maximum width across the elytra 0.6–2.1. Elytra covering most to all of the abdomen; exposing no more than part of the terminal tergite to at least one but fewer than three complete abdominal tergites. The pygidium at least partly exposed beyond the long elytra, or entirely concealed by the ends of the elytra even when viewed from behind (supposedly the defining feature of Aphodiinae). Elytra glossy, or dull. Scutellary striole absent. Wings well developed (always, in British representatives). Exposed abdominal sternites 5–7 (usually 6); all articulated and movable to all fused and immovable (all fused in some Aphodiinae); immovably joined when present, 2, or 4–6. Abdominal segment 8 with apparently functional spiracles, or apparently without functional spiracles.
Adult habitat, ecology. Not predacious; phytophagous, or consuming decaying plant material, or coprophagous (Melolonthinae feeding on leaves, Scarabaeinae and Aphodiinae on dung, Cetoniinae on nectar); in living vegetation, or in decaying plant material, or associated with dung.
Larvae. Larvae not predacious (mostly curved, C-shaped ‘curl-grubs’, with brownish head, three pairs of well-developed legs and 4-segmented antennae); phytophagous (Melolonthinae notably on roots), or consuming decaying plant material (Cetoniinae), or boring into dead wood, or coprophagous (Aphodiinae, Scarabaeinae); on living vegetation, in decaying plant material, and in dung.
Classification. Suborder Polyphaga; Infraorder Scarabaeiformia; Superfamily Scarabaeoidea.
Worldwide and British representation. About 30000 species worldwide. 81 species in Britain; genera in Britain 30; Aphodius, Cetonia, Copris, Gnoremus, Melolontha, Onthophagus, Phyllopertha, Psammobius, Typhaeus, etc. E.g., Aphodius villosus (Hairy Aphodius); Aphodius distinctus; Melolontha melolontha (Common Cockchafer); Cetonia aurata (Rose Chafer); Phyllopertha horticola (Sutherland Bracken-clock); Copris lunaris (Lunar-headed Dung-beetle); Gnoremus variabilis (8-spotted Oak-beetle); Onthophagus taurus (Bull-headed Dung-beetle); Phyllopertha horticola; Psammobius asper (Channel-necked Psammodius); Typhaeus typhoeus. Curtis also illustrated the spectacular mainland-European Polyphylla fullo.
General comments. The scarab beetles constitute a taxonomically difficult group, and a satisfactory classification at world level has yet to be achieved. Of the fairly distinct series that have long been recognised, only six are represented in Britain. Of these, Geotrupidae, Trogidae and (by some authorities) Aphodiidae are now treated as distinct families, with the rest - Scarabaeinae (dung beetles), Melolonthinae ('chafers') and Cetoniinae - awarded subfamily status. This sensu lato description is not taxonomically judgemental, but seems appropriate in the present context.
Illustrations. • Aphodius villosus (Hairy Aphodius: B. Ent. 027). • Aphodius villosus: B. Ent. 027, legend+text. • Aphodius villosus: B. Ent. 027, text cont.. • Psammobius asper (Channel-necked Psammobius: B. Ent. 258). • Psammobius asper (details, B. Ent. 258). • Psammobius asper: B. Ent. 258, legend+text. • Aphodius (10 spp.), Colobopterus (3 spp.): Fowler 4, 100 (1890). • Fowler 4, 100 (1890): original legend.. • Aphodius (12 spp.), Oxyomus sylvestris (as O. porcatus): Fowler 4, 101 (1890). • Fowler 4, 101 (1890): original legend.. • Aphodius distinctus (Rye & Fowler VIII3). • Phyllopertha horticola (Sutherland Bracken-clock: B. Ent. 526). • Phyllopertha horticola (B. Ent. 526, legend+text). • Phyllopertha horticola (B. Ent. 526, text cont.). • Cetonia stictica (Spotted Chafer: B. Ent. 374. Adventive). • Cetonia stictica: B. Ent. 374, legend+text. • Cetonia stictica: B. Ent. 374, text cont.. • Cetonia aurata (Rose Chafer, May-bug: Giles Watson). • Copris lunaris (Lunar-headed Dung-beetle: B. Ent. 414). • Copris lunaris: B. Ent. 414, legend+text. • Copris lunaris: B. Ent. 414, text cont.. • Polyphylla fullo (Kent Cockchafer: B. Ent. 406. Mainland-European). • Polyphylla fullo (details, B. Ent. 406). • Polyphylla fullo : B. Ent. 406, legend+text. • Polyphylla fullo : B. Ent. 406, text cont.. • Onthophagus taurus (Bull-headed Dung-beetle: B. Ent. 052). • Onthophagus taurus: B. Ent. 052, legend+text. • Onthophagus taurus: B. Ent. 052, text cont.. • Gnoremus variabilis (8-spotted Oak-beetle): B. Ent. 286. • Gnoremus variabilis: B. Ent. 286, legend+text. • Gnoremus variabilis: B. Ent. 286, text cont.. • Copris lunaris, Onthophagus taurus, O. nutans, O. fracticornis, O. nudicornis: Fowler 4, 99 (1890). • Fowler 4, 99 (1890): original legend.. • Hoplia, Omaloplia (as Homoloplia), Serica, Melalontha, Amphimallon (as Rhizotragus), Phyllopertha, Euchlora (as Anomala), Cetonia, Gnorimus: Fowler 4, 103 (1890). • Fowler 4, 103 (1890): original legend.. • Aegialia (3 spp.), Pleurophurus caesus, Psammobius asper, Pammobius porcicollis (with Geotrupidae and Trogidae: Fowler 4, 102 (1890). • Fowler 5, 102 (1890): original legend.. • Trichius fasciatus (with Buprestidae, Throscidae, etc.): Fowler 4, 104 (1890). • Fowler 4, 104 (1890): original legend. • Aphodius nemoralis, with unrelated taxa: Fowler Suppl. 14, 1913. • Fowler 6, 14 (1913): original legend.. • Amphimallon ochraceus and Diastictus vulneratus (with unrelated taxa): Fowler Suppl. 15, 1913. • Fowler Suppl. 15, 1913: original legend. • Phyllopertha horticola (Rye & Fowler VIII1). • Typhaeus typhoeus (Rye & Fowler VIII2).
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’.
