British insects: the families of Coleoptera
British insects: the families of Coleoptera | |
False Firefly Beetles.
General appearance. 5–7 mm long. Body length/maximum body width 2.05–4.85. Elytral length/pronotal length 4.25–4.95. 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. Body (of males) not noticeably widest either behind the thorax, or at the rear. Beetles elongate; not necked; conspicuously waisted; with male elytra orange-brown, covered in pale hairs. Upper surfaces of body non-glabrous; not bristly; with neither scales nor scale-like setae.
Detailed morphology. 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 (females), or about half the insect's head to tail length (males); (10–)11 segmented; filiform (moniliform, females), or pectinate (males). Antennal insertions visible from above; not in fossae. Mandibular prosthecae absent. Pronotal length/maximum pronotal width 0.47–0.68. Prothorax without notopleural sutures. The scutellum not elevated. Metaventrite without a transverse groove. Tarsal segmentation formula 5, 5, 5. The tarsi exhibiting bilobed segments; without ‘hidden’ segments. Front tarsi with as many segments as the mid-tarsi; 5-segmented. Mid-leg tarsi 5-segmented; pentamerous. The claws of the mid-leg tarsi not appendaged (but with setae near their bases). The claws of the mid-leg tarsi simple; without an associated empodium. Hind tarsi with as many segments as the mid-tarsi; 5-segmented. Elytra present (males), or absent (females). Elytral length/maximum width across the elytra 1.7–2.16. Elytra (of males) covering most to all of the abdomen; exposing no more than part of the terminal tergite; somewhat truncate to not truncate. Scutellary striole absent. Elytra non-glabrous. Wings well developed (males), or absent or much reduced (females). Exposed abdominal sternites 6–7 (males), or 9 (females); all articulated and movable. Abdominal segment 8 with apparently functional spiracles.
Adult habitat, ecology. Predacious (on snails).
Classification. Suborder Polyphaga; Infraorder Elateriformia; Superfamily Cantharoidea.
Worldwide and British representation. About 80 species worldwide; genera 4. 1 species in Britain; genera in Britain 1; Drilus. E.g., Drilus flavescens.
General comments. The eyes quite small, and circular, unlike those of Buprestidae.
Illustrations. • Drilus flavescens, male and female (with unrelated taxa): Fowler 4, 116 (1890). • Fowler 4, 116 (1890): original legend.. • Drilus flavescens (Rye & Fowler).
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’.
