Aspidapion aeneum (Fabricius, 1775)
A widely distributed weevil occurring throughout the Palaearctic region north to southern Scandinavia. The U.K. distribution includes the southeast north to the Humber, there are very few west country records and in Wales it is coastal. This seems a little surprising as the species is generally common within its range while the host plant is common throughout the U.K. The typical habitat is disturbed ground where the foodplant grows; roadsides, field and agricultural margins and parkland etc. and it is common in urban situations. Foodplants include a range of Malvaceae; Malva alcea L. (greater musk-mallow), Malva sylvestris L. (mallow) and Alcea rosea L. (hollyhock). In the U.K. it occurs on M. sylvestris. Adults overwinter among vegetation and soil near the host and become active on the plants in April or early May depending upon the season. They may be found through the season until the autumn. During the summer a single plant may host many adults which will quickly become obvious when beaten over a tray. Larvae feed in the lower parts of the stems and the roots; they excavate long chambers in the stems where they feed and will ultimately pupate. Adults eclose in late summer and remain on the host into the autumn before overwintering.
2.9-3.6mm. Readily identified in the field, especially when found on the foodplant, by the convex-oval form and smooth, bright metallic elytra. With a lens the deep furrow on the frons and very long scutellum are obvious.
Aspidapion aeneum 1
Aspidapion aeneum 2
Aspidapion aeneum 3
Aspidapion aeneum 4
The head is convex with a broad and deep longitudinal furrow on the frons; the male rostrum is as long as the pronotum while that of the female is longer. Antennae inserted on the basal third of the rostrum; pale with a dark club. Pronotum slightly transverse; sides more or less straight and constricted behind the front angles and in front of the hind angles. Basal impression short and deep. Scutellum twice as long as wide and convex in cross section. Elytra oblong and convex; metallic green, sometimes blue or bronze. Striae well impressed and almost impunctate, the base of the first stria does not extend as far as the scutellum. Interstices much broader than the striae and flat or only weakly convex; very finely punctured and sometimes finely pubescent at the base, otherwise glabrous. Legs black to very dark brown. Male tibiae with an internal spine at the apex. Claws curved and strongly toothed at the base.