Aclypea Reitter, 1884

A Holarctic species although only sparsely distributed in the Nearctic region, the main centre of its distribution is the western Palaearctic. In the U.K. there are records scattered through England, Wales and Scotland including the Western Isles. As with other species of the genus it is phytophagous, feeding on various Gramineae and Brassicaceae, preferring various Amaranthaceae (Chenopodioideae), and has at various times been a serious pest of beet crops on the continent. Adults occur from early spring and the typical habitats are meadows, wasteland and arable land where the adults, although mainly nocturnal, may be seen walking during the warmer months. Adults overwinter among tussocks and litter etc. on field margins and emerge in the spring when their food source is germinating. Females lay batches of eggs in the soil at a depth of seven or eight cm around the base of host plants and larvae emerge within a week or so, the egg laying period extends into the summer and so larvae in all stages of development may be present in a crop and large populations of adults may build up. Eggs are very sensitive to soil humidity and die off in dry soil and so outbreaks tend to occur in years with a moderately dry spring and damp summer. Fresh larvae emerge from the soil and feed on low foliage, they often remain on the soil surface and consume any hanging leaves but as they grow they feed voraciously and ascend the stems to access fresh foliage and it is older, almost fully-grown larvae that do most damage, they develop very rapidly, passing through three instars, and are fully developed within two to three weeks. At this stage descend the stems and move into the soil to pupate in a cell at a depth of one to five cm.  Adults eclose between ten and fifteen days later, and after a period of hardening and pigmentation, leave the soil and begin to feed on the plants, mostly eating away the edges of leaves, but not so extensively as the larvae which may completely strip plants of foliage. Adults enter a summer diapause but may continue feeding through late summer and autumn but they do not become sexually mature until they have overwintered and spent time maturation feeding during the following spring. Adults generally pass the winter under debris or among leaf litter rather than in the soil and they may become active during mild spells. The entire cycle from egg to adult takes about a month and there is a single generation each year. The larvae are of the normal silphine type but typically have pale margins, a distinguishing feature of the genus, although all dark specimens occur and the defining character of the genus is the presence of a ventral as well as a mesal serrate edge to the mandibles.

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9-12mm. An elongate and rather depressed species; black to dark brown and with fine, pale and recumbent pubescence which is dense on the head but otherwise even and diffuse. Antennal segments 1-3 elongate, 4-7 only slightly so, and 8-10 form an indistinct club. Labrum deeply emarginate. Eyes relatively small and without erect setae along the posterior margin. Temples convex. Pronotum distinctly shaped; laterally rounded and without borders, anterior margin straight and hind margin produced backwards. Surface punctured although there may be smooth areas anteriorly either side of the middle and occasionally others near the midline. Scutellum large, with angled lateral margins and acute apex. Base of elytra narrower than the base of the pronotum, each elytron with four longitudinal ridges distinct to the apical third. Punctures on the elytra shallow and separated by at least their diameter.  Pronotum and elytra with distinct isodiametric microsculpture. Tibiae with longitudinal carinae and fine spines on the external margins; male hind tibiae with a fine curved spine at the apex. Claws red. Male-pro tarsi dilated.