Phyllobius vespertinus (Fabricius, 1792)

Now generally accepted as a distinct species but still regarded by some as conspecific with P. pyri (Linnaeus, 1758), a supposed ecological difference is that the present species uses various herbaceous plants as hosts while pyri is restricted to trees and shrubs, but there are many references to vespertinus using woody plants (see here). This may be due to the adults being widely polyphagous but using only herbaceous plants as hosts (a not uncommon habit among weevils and leaf beetles), or that there are regional differences in host plants, or maybe there are regional variations in morphology that confuse the situation. Through much of Europe it is regarded as herbaceous-polyphagous but even so there are convincing references to its using various trees, and even to it causing damage to fruit trees in orchards. The UK situation seems to be pretty clear, i.e. that it uses herbaceous plants as hosts, and for this reason alone we describe the species as such here but it should be understood that the real situation is likely to be less clear-cut. The European distribution is mostly western and central but the species has also been recorded from Ukraine, Iran and as Far East as Siberia, to the north it extends into the UK, Denmark and southern Fennoscandia and while it is widespread in Germany and Southern Poland it is otherwise absent from most of the Baltic countries. To the south it reaches the Mediterranean in France and it occurs in Northern Italy, Romania and Bulgaria. Throughout much of this range it is locally common and sometimes abundant and it is present from lowland to middle mountain latitudes in a wide range of habitats. In the UK it is mostly coastal. It is very local and rare although it tends to be common where it occurs; it is rather sporadic along the eastern coast from Kent to the Scottish border and there are records from Cumbria and the Manchester district. Adults first appear in March and are generally common through May and June although they have a wider season on the continent, from March until October. Typical UK habitats include saltmarshes and damp field margins but in Europe the species is more general, occurring also on wetland margins, grassland, dunes, moorland, floodplains, open deciduous woodland, hedgerows and well-vegetated disturbed areas. Known hosts include a range of herbaceous plants and grasses; in the UK often Sea Wormwood (Artemisia maritima L. Asteraceae)) but more generally various Asteraceae and Rosaceae as well as Ground Elder (Aegopodium podagraria L. Apiaceae) and Meadow vetchling (Lathyrus pratensis L. Fabaceae). Larvae develop in the soil feeding externally on roots, they are active and may move between plants to feed and it is likely that they descend into the soil to overwinter, as is typical of the group. Pupation very probably occurs from late winter, depending on the season, to produce the new spring generation of adults from March.