Insects of Britain and Ireland: the families of Coleoptera
Unless indicated otherwise, the following attributes are implicit throughout the descriptions, except where the characters concerned are inapplicable.
General appearance. Beetles not terrapin-like in shape, and without flattened and clear margins to both thorax and elytra; not asymmetrically humped and tapered; without warning colouration; not luminescent. The underside without a plastron of hydrofuge hairs. Beetles not conglobulating; not clicking and jumping.
Detailed morphology. Beetles without a rostrum. The head not covered by the thorax. Eyes present; two, entire; not accommodating the antennae in a notch. Mandibles present. The maxillae without stylet-like lobes. The maxillary palps not especially elongated. Antennae not strongly asymmetric; not elbowed; without a much-elongated scape. Antennal scape not swollen. Antennal clubs not lamellate; not comprising two small basal segments and a large terminal one; without a cupule. Antennal segment 8 not smaller than 7 and 9.
Posterior edge of the pronotum not crenulate. Prothorax not hooded with anterior bumps. Scutellum conspicuous. The prosternal process present; entire; complete. Metaventrite without a transverse groove. Mid- and hind-legs not as in Gyrinidae (q.v.). The fore-leg coxae countersunk in procoxal cavities. The mid-leg coxae countersunk in mesocoxal cavities. Hind-leg coxae not much enlarged; moveable; not shaped posteriorly to receive the femur; not concealing the hind femora; not incorporated with the metasternum in a flat, median longitudinal keel; without the steep transverse declivity characteristic of Dryopoidea. The tarsi without hidden segments. The front tarsi present and well developed. Hind tarsi without swimming hairs; not flattened and oar-like.
Elytra present; not individually tapered; meeting along the length of the mid-line; covering most to all of the abdomen; not iridescent. Wings well developed; not apically rolled; veined; not fringed. The end of the abdomen not extended as a long, narrow point beyond the ends of the elytra.
Adult habitat, ecology. Land-dwellers; not predacious.
Larvae. The larvae neither strongly flattened nor disc-like; not C-shaped; without abdominal gills. The abdominal apex without a respiratory chamber. The last abdominal segment without a long median spine.
Larvae non-aquatic; not predacious.
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. delta-intkey.com’.