| | Insects of Britain and Ireland: Coleoptera-Scarabaeoidea (dung beetles and chafers) |
~Melolonthinae tribe Hopliini
General appearance. 7–11 mm long. Body length/maximum body width 1.54–1.75. 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. 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 non-glabrous; not bristly; exhibiting scales or scale-like setae (with very short scales, and bluish scales on the underside).
Detailed morphology. Beetles not prognathous. Inclination of the head slight (the labrum and mouthparts often visible from above). Eyes two, entire; not strongly protuberant; without bristles; finely facetted. Ocelli absent. The labrum concealed beneath the clypeus. Mandibles absent or vestigial (in some Cetoniini), or present; with a well developed mola; with well developed prosthecae. The mandibular apices simple, or bidentate or bilobed. The incisor edges of the mandibles simple. 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 very short (not reaching the middle of the prothorax); strongly asymmetric; not elbowed; 9 segmented, or 10 segmented; clubbed. Antennal clubs not flattened, tightly lamellate; 3 segmented. Antennal insertions hidden from above; not in fossae.
Prothorax shorter than wide. Pronotal length/maximum pronotal width 0.62–0.83. The pronotum with lateral keels (pronotal carinae); keels complete. Prothorax at its widest not markedly narrower than the adjoining part of the abdomen. Prothorax without notopleural sutures. Scutellum well developed and conspicuous; not elevated; anteriorly simple; posteriorly narrowly rounded or acute, or broadly rounded or obtusely angulate. The prosternal process present. The prosternal process entire. The prosternal process slightly overlapping the mesoventrite. Metaventrite without a transverse groove. The fore-leg coxae countersunk in ‘procoxal cavities’. The fore-leg coxal cavities closed behind externally; broadly closed; narrowly separated; narrowly separated; strongly transverse; without lateral extensions; broadly closed internally (Hopliin1). The mid-leg coxae countersunk in ‘mesocoxal cavities’; separated by less than the shortest diameter of the cavity, or more than the shortest diameter of the cavity. The mid-leg coxal cavities narrowly separated to moderately to widely separated; not or scarcely oblique; open laterally. Hind-leg coxae extending laterally to meet the elytra. Tarsal segmentation formula 5, 5, 5. The tarsi without bilobed segments; always? without ‘hidden’ segments. Tarsal claws one, or two (the posterior tarsi with only one, which is split apically); when paired, unequal. 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, or one-toothed or bifid; 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 0.73–1.1. Elytra covering most to all of the abdomen; exposing no more than part of the terminal tergite. The pygidium at least partly exposed beyond the long elytra (though not apparent in Fowler’s illustration - cf. Jessop, 1986). Elytra glossy, or dull. Elytra apunctate, irregularly punctate, or each with fewer than 6 longitudinal lines of punctures or impressed striae. Scutellary striole absent. Elytra with epipleura, or without epipleura. Elytral epipleura if present, falling short of the elytral tips. Wings well developed. Wings without an anal lobe. Wings not apically rolled; veined (radial cell reduced or absent). Wings without a medial fleck. Wings not fringed. Abdominal sternites 6; comprising both fused and moveable components to all fused and immoveable. Basal abdominal sternites immovably joined 5, or 6. Abdominal segment 8 apparently without functional spiracles. The male external genitalia bilobate.
Adult habitat, ecology. On living vegetation; phytophagous (feeding on foliage).
Larvae. Mature larvae minute (less than 3 mm long) (rarely), or small to medium-sized to relatively large. The larvae elongate and more or less parallel-sided; C-shaped in lateral view. Body circular in cross-section. Vestiture restricted to fine hairs or setae. The larvae dorsally only very lightly pigmented or sclerotized; ventrally only very lightly pigmented. The antennae 4 segmented, or 5 segmented (rarely more?). Stemmata absent (usually), or present; on either side of the larval head when present, 1. The frontoclypeal suture between frons and clypeus distinct. The labrum and head capsule separated by a complete suture. Apices of the mandibles with a single lobe or tooth, or bilobed or bidentate, or trilobed or tridentate. The maxillary palps 4 segmented. The labium without ligula between the palps, or with a short ligula between the palps. Labial palps present and segmented; 2 segmented. Mesothoracic legs present and segmented; 2 segmented, or 3 segmented, or 5 segmented; with 1 moveable claw. Visible abdominal segments 9, or 10. Tergum 9 of the abdomen entirely dorsal. The abdomen having functional spiracles on anterior segments (these cribriform); without spiracular tubes. The abdominal apex without a respiratory chamber. Abdominal tergum 8 without amature. The last abdominal segment without cerci.
Larvae in the soil; phytophagous (feeding on roots).
Curved, C-shaped ‘curl-grubs’, with brownish head, three pairs of well-developed legs and mostly 4-segmented antennae; the anus V- or Y-shaped.
Classification. Suborder Polyphaga; Infraorder Scarabaeiformia; Superfamily Scarabaeoidea.
Worldwide and British representation. About 250 species worldwide (?); genera 1 (i.e., Hoplia sensu lato, with about 6 subgenera). 1 species in Britain (H. philanthus); genera in Britain 1; Hoplia.
General comments. The head and scutellum black, the elytra reddish brown, the body with very short, scale-like pubescence above and bluish scales beneath.
A mainly Old World assemblage, but sparingly represented also in the Americas.
Illustrations. • Hoplia, with Cetoniinae, Melolonthinae and Rutelinae: Fowler 4, 103 (1890). HOPLIINAE. 1, Hoplia philanthus. MELOLONTHINAE. 2, Omaloplia ruricola. 3, Serica brunnea. 4, Melolontha melolontha, male; 5, Melolontha hippocastani, female. 6, Amphimallon solstitialis. RUTELINAE. 7, Phyllopertha horticola. 8, Anomala dubia (as Euchlora); 9, A. dubia, var. CETONIINAE. 10, Cetonia aurata; 11, Cetonia cuprea. 12, Gnorimus variabilis; 13, Gnorimus nobilis. From Fowler's plate, with the names from the original legend (q.v.) updated. • Fowler 4, 103 (1890): original legend..
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2012 onwards. Insects of Britain and Ireland: Coleoptera-Scarabaeoidea (dung beetles and chafers). Version: 27th July 2019. delta-intkey.com’.
