Ecology

Features unique to the group can be found in their development; larvae live freely on the surface of leaves and superficially resemble lepidopteran caterpillars, they also behave like them and at least one Neotropical species, Phelypera distigma (Boheman, 1842) forms processionary columns like moths of the Thaumetopoeidae, laying down pheromone trails as they go. They also construct delicate lace-like cocoons on the host plants in which to pupate. Where known all species feed on foliage or herbaceous stems and the habit of building a cocoon seems to be general in the group, some tropical species e.g. members of the Australian genus Gerynassa Pascoe, 1873 (Hyperini) mine leaves as larvae but they also emerge to construct cocoons in which to pupate. Larvae construct cocoons after they have finished developing, these are tough and often elaborate structures made up of a rapidly drying protein matrix secreted from the Malpigian tubules , they vary in colour and build and are attached to trunks, leaves or stems, they often have an open structure but the mesh is close enough to protect the pupa from parasites or predators such as assassin bugs, and in many cases the adult consumes, or partly consumes, the cocoon shortly after emergence. In temperate northern regions members of the group feed on plants of a wide range of families but mainly Apiaceae, Fabaceae, Geraniaceae, Boraginaceae, Carophyllaceae, Lamiaceae, Polygonaceae and Saxifragaceae, and UK species, as well as members of the large genera Brachypera and Hypera generally, tend to be oligophagous. Species of some continental genera e.g. Donus Jekel, 1865 may also be monophagous or polyphagous. Several species are minor pests of agricultural crops but two; Hypera postica (Gyllenhal, 1813) and Brachypera zoilus (Scopoli, 1763) are occasionally very serious pests of clover.

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Description

Our UK fauna can be distinguished by the following description although with a little experience they soon become familiar. Medium sized weevils, 3.1-8.5mm, elongate and rather flattened with a small, transverse head, quadrate to transverse pronotum which is curved laterally and wider than the head and elongate elytra with broad shoulders which are much wider than the pronotum, parallel-sided in the basal half and continuously rounded apically and covering the abdomen. Many have distinctive, though variable, patterns of scales to the pronotum and/or elytra and most species of Hypera can be recognized by the bifid form of these scales, in extreme cases e.g. H. nigrirostris Fabricius, 1775 they are long and divided almost to the base while in Limobius they are truncate or only weakly bifurcate. Rostrum moderately long, at most 3.5 longer than wide at the base, weakly curved and usually parallel-sided, it may widen gradually from the base so that the apex is distinctly wider but it is never dilated in the apical half, scrobes placed laterally and not visible from above. Eyes elliptical and weakly convex, usually occupying most of the lateral margin of the head. Antennal scape short, generally only a little longer than the head-width, and rather abruptly thickened in the apical third, funiculus with six (Limobius) or seven segments, club three segmented, pubescent and usually distinctly elongate. Pronotum without lateral or anterior borders, surface simply convex and usually finely and densely punctured though this is often obscured by scales. Metathoracic epimera not visible beyond the elytral humerus or pronotal base from above. Elytra smoothly convex, without raised interstices or grooves, the vestiture usually consists of dense scales and a row of variously-developed long setae in each interstice, there may also be shorter erect or semi-erect setae among the scales on the pronotum and/or elytra and these are usually obvious along the lateral margins. Legs long and robust. Anterior femora without an internal tooth, anterior tibiae curved internally at the apex, sometimes only weakly so, to produce a sharp angle. Tarsi pseudotetramerous, the small fourth segment often obscured by the bilobed third segment. Claws separate to the base, smooth and lacking a basal tooth.