Polydrusus formosus (Mayer, 1779)

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POLYPHAGA Emery, 1886

CURCULIONOIDEA Latreille, 1802

CURCULIONIDAE Latreille, 1802

ENTIMINAE Schönherr, 1823

POLYDRUSINI Schönherr, 1823

POLYDRUSUS Germar, 1817

Sometimes referred to in the literature as P. splendidus (Herbst, 1784), this locally common weevil occurs throughout Europe, extending north into Scandinavia and the UK and east into Siberia and Mongolia, but does not extend into North Africa, and following introductions it is now established in the north-eastern United States. Here it is widespread across southern and central England, where it appears to be increasing in range, and there are a few coastal records from Wales. Hosts includes a wide range of broadleaf trees e.g. Quercus, Corylus, Crataegus, Populus and Prunus etc. but we find them mostly on Betula, the typical habitats are wooded borders, parkland, gardens and wasteland but they may occur wherever suitable hosts are established. Adults occur from April or May until July or a little later, they browse on leaf and flower buds, young leaves and open blossom and may occasionally be pests of commercially grown fruits; they may damage developing fruits so producing unsightly corky scars on the skin of mature fruit, but large infestations are rare. In some northern continental areas it is a pest of basket willow, Salix viminalis L. Oviposition occurs in the spring after a period of maturation feeding; eggs are laid singly or in small batches in the soil and larvae develop through the spring and summer feeding upon roots, they are fully developed by late summer or autumn and remain in the soil to overwinter, pupation occurs in a subterranean cell in the spring. Adults are readily sampled by beating or sweeping suitable foliage.

Several very similar green weevils are widespread and common in the UK and so specimens will generally need to be examined critically. 5.0-7.0mm. An elongate and slender species, near parallel-sided, with long and slender appendages and uniform dense metallic green, broadly-oval scales to the dorsal and ventral surfaces. Head weakly convex and longitudinally impressed, with broad temples that narrow towards large, slightly protruding eyes, a broad rostrum which is parallel-sided or slightly widened apically and at least as long as the head, and scrobes curved down in front of the eyes. Antennae very long and slender, longer than the forebody, red with a black club; scape straight and abruptly thickened close to the apex, segments 2-8 very elongate, club long and sharply pointed. Pronotum transverse, evenly rounded laterally and broadest about or behind the middle, lateral margins unbordered, anterior and posterior margins almost straight. Elytra with broad, sloping shoulders, in the male tapering gently to an acuminate apex, in the female broader and distinctly widened towards the apex which is less acuminate. Striae without scales, appearing black, interstices densely scaled but lacking semi-erect setae. Legs long, robust and extensively pale; all femora with a small ventral tooth, tibiae without an external ridge, tarsi long and slender with the third segment very strongly bilobed.

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