British Insects: the Families of Coleoptera
British Insects: the Families of Coleoptera |
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~Elateridae.
Click-beetles.
General appearance. 2.8–30 mm long (?). Body length/maximum body width 2.4–3.6. Elytral length/pronotal length 2.35–4.85. 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 to slender; not necked; not waisted. Upper surfaces of body non-glabrous; not bristly; with neither scales nor scale-like setae. Beetles not clicking and ‘jumping’ (the clicking mechanism apparently non-functional).
Detailed morphology. Beetles without a rostrum. The head not covered by the thorax. Inclination of the head slight to very strong. Eyes strongly protuberant, or not strongly protuberant; without bristles; finely facetted. Antennae very short to short; 11 segmented. Antennal scape not swollen. Antennae filiform, or serrate, or pectinate. Antennal insertions visible from above, or hidden from above; ‘countersunk’ within saucer-like fossae, or not in fossae. Mandibular prosthecae absent.
Prothorax shorter than wide. Pronotal length/maximum pronotal width 0.48–1. Prothorax without notopleural sutures. Metaventrite without a transverse groove. The tarsi without bilobed segments; without ‘hidden’ segments. Mid-leg tarsi 5-segmented; pentamerous. Claws of the mid-leg tarsi not appendaged (but sometimes with basal setae). Front tarsi with as many segments as the mid-tarsi; 5-segmented. Hind tarsi with as many segments as the mid-tarsi; 5-segmented. Tarsal claws simple, or one-toothed or bifid, or serrate, denticulate or pectinate; with an empodium between them (this with no more than two setae), or without an associated empodium. Elytral length/maximum width across the elytra 1.7–3. Elytra covering most of the abdomen; exposing no more than part of the terminal tergite; hard. Scutellary striole absent. Elytra non-glabrous. Wings well developed.
Visible abdominal sternites 5; immovably joined 4, or 5 (sternite 5 not moveable on 4). Abdominal segment 8 with apparently functional spiracles.
Habitat, ecology. Not predacious (?); in living vegetation.
General comments. The prothorax (the first segment of the thorax) and the mesothorax (the second segment) are freely movable on one another, and the prosternal extension resembles that in Elateridae (q.v.), but the ‘clicking mechanism’ is apparently non-functional in this family. The labrum is not visible when the beetles are viewed from above.
Larvae. Larvae predacious and not predacious (?); in decaying plant material (or in the soil), or in rotting wood, or in or under bark.
Classification. Suborder Polyphaga; Superfamily Elateroidea.
British representation. Genera 3; 3 species. E.g., Melasis buprestoides (Buprestis-like Melasis).
Illustrations. • Melasis buprestoides (Buprestis-like Melasis: B. Ent. 055). • Melasis buprestoides (details, B. Ent. 055). • Melasis buprestoides: B. Ent. 055, legend+text.
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: 9th June 2008. http://delta-intkey.com’.
