British insects: the families of Coleoptera

L. Watson and M. J. Dallwitz

Chrysomelidae

Including Cassididae, Crioceridae, Hispidae, 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.

Detailed morphology. Beetles 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. 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 ofer 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. Prothorax shorter than wide to longer than wide. Pronotal length/maximum pronotal width 0.18–1.7. 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. Metaventrite without a transverse groove. Hind coxae 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 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; 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. Scutellary striole present, or absent. Elytra usually glabrous. Wings well developed, or absent or much reduced. Exposed abdominal sternites 4–5; all articulated and movable, or comprising both fused and movable components; immovably joined when present, 2. Abdominal segment 8 with apparently functional spiracles, or apparently without functional spiracles.

Adult habitat, ecology. Not predacious; phytophagous (often on leaves, and including pest species such as the Colorado Beetle); in living vegetation.

Larvae. Larvae not predacious; phytophagous (attacking fruits, foliage, tunnelling in stems, etc.); on living vegetation.

Classification. Suborder Polyphaga; Infraorder Cucujiformia; Superfamily Chrysomeloidea.

Worldwide and British representation. 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, Phyllobrotica, Phyllotreta, Prasocuris, Psillioides, Pyrrhalta, Timarcha, 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 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.

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’.

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