Insects of Britain and Ireland: the families of Coleoptera

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L. Watson and M. J. Dallwitz


Including Cassididae, Crioceridae, Hispidae, Megalopodidae, Orsodacnidae, etc.

Leaf-beetles; including the Colorado Beetle and the Bloody-nosed Beetle.

General appearance. 1–18 mm long. Body length/maximum body width 0.93–4.65. Elytral length/pronotal length 1.25–10.85. 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 round to elongate; not necked; not waisted to conspicuously waisted; often brightly coloured, spotted or metallic; exhibiting bright ‘warning colours’, or without ‘warning colouration’. Upper surfaces of body glabrous or subglabrous, or non-glabrous; exhibiting stiff, erect, dark bristles, or not bristly; exhibiting scales or scale-like setae, or with neither scales nor scale-like setae. The underside exhibiting a plastron of hydrofuge hairs, detectable as a bubble when the insect is submerged (in Donaciinae), or without a plastron of hydrofuge hairs.

Detailed morphology. Beetles without a rostrum; prognathous, or not prognathous. Inclination of the head slight to very strong. Eyes strongly protuberant, or not strongly protuberant; not accommodating the antennae in a notch (but sometimes emarginate); bristly, or without bristles. Ocelli absent. The labrum at least partly visible in antero-dorsal view (mostly), or concealed beneath the clypeus (some Hispinae); labrum when recordable, i.e. usually, mostly moderately to heavily sclerotized. Mandibles variously with a well developed mola, or with a reduced mola, or without a mola (commonly). The mandibular apices simple, or bidentate or bilobed, or multidentate or multilobed. The incisor edges of the mandibles variously simple, or with a single tooth, or with two or more teeth (some Clytrini and Alticini). The maxillae with distinct galea and lacinia apically to the palp. The apical segment of the maxillary palps cylindrical to fusiform (mostly, except in Chrysomelinae), or somewhat expanded and truncate to subtriangular, or securiform to cultriform. The apical segment of the labial palps not expanded apically (mostly), or more or less expanded apically (some Chrysomelinae). Antennae very short to long, but not exceeding the insect’s head to tail length; 3 segmented, or 7–11 segmented (not capable of being directed backwards over the body, unlike those of Cerambycidae). Antennal scape swollen, or not swollen. Antennae filiform, or gradually expanding towards the apex, or serrate. Antennal insertions visible from above, or hidden from above; ‘countersunk’ within saucer-like fossae, or not in fossae.

Cervical sclerites present. Prothorax shorter than wide to longer than wide. Pronotal length/maximum pronotal width 0.18–1.7. The pronotum with lateral keels (pronotal carinae), or without lateral keels; keels when present, complete, or incomplete. Posterior edge of the pronotum distinctly crenulate (e.g., Cryptocephalini), or not crenulate. Prothorax at its widest markedly narrower than the adjoining part of the abdomen (often), or not markedly narrower than the adjoining part of the abdomen; with neither produced front corners nor serrated sides. Prothorax without notopleural sutures. Scutellum conspicuous (e.g., Megalopodinae, Orsodacnidae), or highly reduced; when applicable, elevated above the mesoscutum in lateral view, or not elevated (e.g., Megalopodinae, Orsodacnidae); anteriorly simple (usually), or notched (rarely); posteriorly variously narrowly rounded or acute, or broadly rounded or obtusely angulate, or truncate, or emarginate. The prosternal process present; complete (mostly), or incomplete (in some Galerucinae); falling short of the mesoventrite, or slightly overlapping the mesoventrite to moderately or strongly overlapping the mesoventrite, or concealing most or all of the mesoventrite (some Hispinae). Metaventrite without a transverse groove. The fore-leg coxae countersunk in ‘procoxal cavities’. The fore-leg coxal cavities open behind externally, or closed behind externally; broadly open, or narrowly open, or narrowly closed, or broadly closed; medianly confluent (e.g., some Galerucini), or narrowly separated, or quite widely separated; strongly transverse, or slightly transverse, or circular to longer than wide; with narrow lateral extensions, or without lateral extensions; internally closed by a slender bar, or broadly closed internally. 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 contiguous (some Cryptocephalinae), or narrowly separated, or moderately to widely separated; not or scarcely oblique; open laterally. Hind-leg coxae variously contiguous or narrowly separated, or widely separated; not much enlarged; not markedly extended laterally (mostly), or extending laterally to meet the elytra (Megalopodidae); not shaped posteriorly to receive the femur. Tarsal segmentation formula 4, 4, 4. The tarsi usually exhibiting bilobed segments, or without bilobed segments; with a tiny penultimate segment hidden by distal lobing of the fourth and fused to the fifth. Front tarsi with as many segments as the mid-tarsi; 4-segmented, or 5-segmented (depending on interpretation). Mid-leg tarsi 4-segmented, or 5-segmented; pseudotetramerous; the penultimate segment not distinctly shorter than the antepenultimate one (e.g., at least some Hispinae), or distinctly shorter than the antepenultimate one (mostly). 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; without an associated empodium. Hind tarsi with as many segments as the mid-tarsi; 4-segmented, or 5-segmented (the basal segment shorter than the rest together).

Elytral length/maximum width across the elytra 0.7–3.72. Elytra not individually tapered; covering most to all of the abdomen; exposing no more than part of the terminal tergite, or at least one but fewer than three complete abdominal tergites to at least three complete abdominal tergites (usually); not truncate; hard; usually glabrous. Elytra with six or more longitudinal lines of punctures, or with six or more impressed striae, or apunctate, irregularly punctate, or each with fewer than 6 longitudinal lines of punctures or impressed striae; the lines per elytron when more than five, 6–7, or 8 to 11. Scutellary striole present, or absent (e.g., Megalopodinae, Orsodacnidae). Wings well developed, or absent or much reduced. Wings with an anal lobe, or without an anal lobe. Wings with a medial fleck, or without a medial fleck; the medial fleck when present, not bisected by a vein. Abdominal sternites 4–5; all articulated and moveable, or comprising both fused and moveable components. Basal abdominal sternites immovably joined when present, 2. Abdominal segment 8 with apparently functional spiracles, or apparently without functional spiracles. The male external genitalia chrysomeloid (mostly), or cucujiform (Orsodacnidae only).

Adult habitat, ecology. Adult beetles seemingly nearly always land-dwellers (but those associated with helophytes are likely to be found struggling in water, or floating), or water-beetles (? - Donaciinae not only have aquatic larvae, but the adults have a hydrofuge plastron, cf. truly aquatic Hydrophilidae); not predacious; on living vegetation; phytophagous (often on leaves, and including pest species such as the Colorado Beetle).

Larvae. Mature larvae minute (less than 3 mm long) to relatively large. The larvae scarabaeiform; elongate and more or less parallel-sided, or oblong to ovate; C-shaped in lateral view (commonly, including Donaciinae and many Chrysomelinae), or not C-shaped. Body circular in cross-section (commonly), or somewhat flattened, or strongly flattened (some Cassidini, some Megalopodidae). Vestiture restricted to fine hairs or setae. The larvae dorsally heavily pigmented or sclerotized, or dorsally only very lightly pigmented or sclerotized; ventrally only very lightly pigmented. The antennae 1 segmented (some Galerucinae), or 2 segmented, or 3 segmented; 0.15–0.5 x the head width. Stemmata present, or absent (some Galerucinae, Sagrinae); on either side of the larval head when present, 1 (e.g., some Galerucinae, Sagrinae), or 5 (Donaciinae, some Cryptocephalinae), or 6. The larval fronto-clypeus not extended forwardly. The frontoclypeal suture between frons and clypeus indistinct or absent, or distinct. The labrum and head capsule separated by a complete suture, or partly fused, with an incomplete suture to completely fused, with no suture apparent (Cryptocephalinae). Apices of the mandibles with a single lobe or tooth (Sagrinae), or bilobed or bidentate (Donaciinae), or bilobed or bidentate to trilobed or tridentate (Cryptocephalinae), or multilobed or multidentate. The maxillary palps 2 segmented (Sphaeroderma), or 3 segmented, or 4 segmented. The labium without ligula between the palps (Criocerinae), or with a short ligula between the palps, or with a ligula at least as long as the palps (some Galerucinae). Labial palps present and segmented; 1 segmented (e.g., Donaciinae, Criocerinae, Sphaeroderma), or 2 segmented. Mesothoracic legs present and segmented; 4 segmented (Donaciinae), or 5 segmented; with 1 moveable claw. Visible abdominal segments in British representatives, 10. Tergum 9 of the abdomen entirely dorsal, or extending to the underside (some Galerucinae). The abdomen having functional spiracles on anterior segments (usually, these annular, annular-biforous or cribriform), or with functional spiracles confined to the the eighth segment (in Donaciinae); with the spiracles on the eighth segment borne at the ends of spiracular tubes (in Donaciinae), or with anterior and 8th-segmental spiracles borne at the ends of a series of spiracular tubes (Cassidini), or without spiracular tubes. The larvae without abdominal gills. The abdominal apex without a respiratory chamber. Abdominal tergum 8 without amature. The posterior segments without swimming hairs. The last abdominal segment without cerci.

Larvae non-aquatic (mostly), or aquatic (those of Donaciinae obtaining air when submerged by piercing the tissues of the helophytic plants on which they feed with their modified, spine-like 8th spiracles); often found in living vegetation; phytophagous (attacking fruits, foliage, tunnelling in stems, roots (root-worms), mining leaves, etc.).

Classification. Suborder Polyphaga; Infraorder Cucujiformia; Superfamily Chrysomeloidea.

Representation in Britain and Ireland, and worldwide. At least 35000 species worldwide; genera about 2500 (!). 254 species in Britain; genera in Britain 52; Calomicrus, Cassida, Cryptocephalus, Donacia, Entomoscelis, Lema, Labiostomis, Lamprosoma, Leptinotarsa, Macroplea, Mantura, Orsodacne (Orsodacnidae), Phyllobrotica, Phyllotreta, Prasocuris, Psillioides, Pyrrhalta, Timarcha, Zeugophora (Megalopodidae), etc. E.g., Phyllobrotica quadrimaculata (Orange-and-black Galeruca); Mantura matthewsii (Matthews's Haltica); Cassida salicorniae Curtis, = C. vittata: Samphire Tortoise-beetle); Entomoscelis adonidis (Lincolnshire Chrysomela: not indigenous); Lema cyanella (Spencean Crioceris); Cryptocephalus bipunctatus (Yellow-tipped Cryptocephalus); Donacia claviceps, Pyrrhalta viburni (Striped-legged Galeruca); Labiostomis tridentata; Lamprosoma concolor (Knotted-horned Byrrhus); Calomicrus circumfuscus (Striped Galeruca); Phyllotreta ochripes; Prasocuris junci (Blue Helodes); Psilliodes chalcomera (Thigh-spotted Altica); Macroplea appendiculata (Cambridge Macroplea); Leptinotarsa decemlineata (Colorado Beetle); Timarcha tenebricosa (Bloody-nosed Beetle).

General comments. Beetles terrestrial, but ubiquitous, and species associated with plants of wet places commonly found near or struggling in water; very variable in form, usually robust, usually not pubescent; tibiae with fewer than two spurs on one or more legs.; metaventrite (= metasternum) without a transverse groove, by contrast with Buprestidae; cervical sclerites absent.

Illustrations. • Calomicrus circumfusus (Striped Galeruca: B. Ent. 370). • Calomicrus circumfusus: B. Ent. 370, legend+text. • Calomicrus circumfusus: B. Ent. 370, text cont.. • Cassida salicorniae Curtis = C. vittata (Samphire Tortoise-beetle: B. Ent. 127). • Cassida salicorniae Curtis = C. vittata: B. Ent. 127, legend+text. • Cassida salicorniae Curtis = C. vittata: B. Ent. 127, text cont.. • Cryptocephalus biguttatus (Yellow-tipped Cryptocephalus: B. Ent. 35). • Cryptocephalus biguttatus: B. Ent. 35, legend+text. • Cryptocephalus biguttatus: B. Ent. 35, text cont.. • Donacia vulgaris, with dissections from D. cincta Germ." = D. clavipes?): B. Ent. 494. • Donacia vulgaris: B. Ent. 494, legend+text. • Donacia vulgaris: B. Ent. 494, text cont.. • Entomoscelis adonidis (Lincolnshire Chrysomela: not indigenous. B. Ent. 111). • Entomoscelis adonidisa: B. Ent. 111, legend+text. • Entomoscelis adonidisa: B. Ent. 111, text cont.. • Lamprosoma concolor (Knotted-horned Byrrhus: B. Ent. 347). • Lamprosoma concolor: B. Ent. 347, legend+text. • Lamprosoma concolor: B. Ent. 347, text cont.. • Lema cyanella: (Spencean Crioceris: B. Ent. 323). • Lema cyanella: B. Ent. 323, legend+text. • Lema cyanella: B. Ent. 323, text cont.. • Macroplea appendiculata (Cambridge Macroplea: B. Ent. 318). • Macroplea appendiculata (B. Ent. 318, details). • Macroplea appendiculata: B. Ent. 318, legend+text. • Macroplea appendiculata: B. Ent. 318, text cont.. • Mantura matthewsi (Curtis): Matthews's Haltica, B. Ent. 435. • Mantura matthewsi (Curtis): B. Ent. 435, legend+text. • Mantura matthewsi (Curtis): B. Ent. 435, legend cont.. • Phyllobrotica quadrimaculata (Orange-and-black Galeruca): B. Ent. 366. • Phyllobrotica quadrimaculata: B. Ent. 366, legend+text. • Phyllobrotica quadrimaculata: B. Ent. 366, text cont.. • Phyllotreta ochripes: B. Ent. 630. • Phyllotreta ochripes: B. Ent. 630, legend+text. • Phyllotreta ochripes: B. Ent. 630, text cont.. • Prasocuris junci (Blue Helodes: B. Ent. 506). • Prasocuris junci (details, B. Ent. 506). • Prasocuris junci: B. Ent. 506, legend+text. • Prasocuris junci: B. Ent. 506, text cont.. • Psylliodes chalcomera (Thigh-spotted Altica: B. Ent. 486). • Psylliodes chalcomera: B. Ent. 486, legend+text. • Psylliodes chalcomera: B. Ent. 486, text cont.. • Pyrrhalta viburni (Striped-legged Galeruca: B. Ent. 371). • Pyrrhalta viburni: B. Ent. 371, legend+text. • Pyrrhalta viburni: B. Ent. 371, text cont.. • 12 Cassida species and Pilemostoma fastuosa: Fowler 4, 142 (1890). • Fowler 4, 142 (1890): original legend.. • 13 Psylliodes species: Fowler 4, 141 (1890). • Fowler 4, 141 (1890): original legend.. • Donacia, Lema, Macroplea, Plateumaris, Zeugophora: Fowler 4, 127 (1890). • Fowler 4, 127 (1890): original legend.. • Clytra, Cryptocephalus (4 spp.), Labidostomis, Lilioceris, Oulema (3 spp.): Fowler 4, 128 (1890). • Fowler 4, 128 (1890): original legend. • Cryptocephalus (13 species): Fowler 4, 129 (1890). • Fowler 4, 129 (1890): original legend.. • Chrysolina (10 spp.), Lamprosoma, Timarcha: Fowler 4, 130 (1890). • Fowler 4, 130 (1890): original legend.. • Chrysolina (5 spp.) Chrysomela (3 spp.), Phytodecta (3 spp.): Fowler 4, 131 (1890). • Fowler 4, 131 (1890): original legend.. • Gastrophysa, Hydrothassa (3 spp.), Phaedon (4 spp.), Phyllodecta (3 spp.), Plagiodera: Fowler 4, 132 (1890). • Fowler 4, 132 (1890): original legend.. • Agelastica, Calomicrus (3 spp.), Galerucella, Lochmaea, Phyllobrotica, Prasocuris: Fowler 4, 133 (1890). • Fowler 4, 133 (1890): original legend.. • Galeruca, Galerucella, Longitarsus (5 spp.), Pyrrhalta, Sermylassa: Fowler 4, 134 (1890). • Fowler 4, 134 (1890): original legend.. • Longitarsus (13 spp.): Fowler 4, 135 (1890). • Fowler 4, 135 (1890): original legend.. • Altica (2 spp.) and Longitarsus (9 spp.): Fowler 4, 136 (1890). • Fowler 4, 136 (1890): original legend.. • Haltica, Hermaeophaga and Phyllotreta (10 spp.): Fowler 4, 137 (1890). • Fowler 4, 137 (1890): original legend.. • Aphthona (7 spp.), Apteropeda, Batophila, Pyhllotreta, Sphaeroderma: Fowler 4, 138 (1890). • Fowler 4, 138 (1890): original legend.. • Chalcoides, Crepidodera, Derocrepis, Lythraria, Mantura (4 spp.), Mniophila, Podagrica: Fowler 4, 139 (1890). • Fowler 4, 139 (1890): original legend.. • Chaetocnema (54 spp.), Chalcoides (4 spp.), Epitrix (2 spp.), Hippuriphila: Fowler 4, 140 (1890). • Fowler 4, 140 (1890): original legend.. • Cryptocephalus, Galerucella, Gynandrophthalma, Lochmaea, Longitarsus, Orsodacne, Oulema (with Bruchidae and Cerambycidae): Fowler Suppl. 17, 1913. • Fowler Suppl. 17, 1913: original legend. • Cassida, Chaetocnema, Crepidodera, Dibolia, Longitarsus (with Tenebrionidae and Abdera: Fowler Suppl. 18, 1913. • Fowler Suppl. 18, 1913: original legend.. • Phyllotreta ochripes, Labiostomis tridentata (Janson 243, 255).

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.’.