Donacia simplex Fabricius, 1775

This very widespread and generally common Palaearctic species occurs from Portugal to Mongolia and eastern Siberia, it has also been listed from Japan but this may be based on misidentified specimens, in Europe it is a mainly lowland species, extending to about 700 m; it is common throughout the region and extends north to the UK and beyond the Arctic Circle in Scandinavia, it is present on most of the Mediterranean islands and widespread in North Africa but absent from the Atlantic islands. In the UK it is common across England and Wales though less so in the north, sporadic and very local in Scotland, including the Outer Hebrides, and local across central Ireland. Adults are active from March until September but may sometimes appear during the winter. Typical habitats are margins of ponds, reservoirs and streams etc. where they occur on various plants including Sweet-grass, Glyceria fluitans R. Br., Bullrush, Typha latifolia L., Common Reed, Phragmites australis (Cav.) and sedges, Carex L. but especially bur-reeds, Sparganium L., and usually where the vegetation is dense. Adults are diurnal and are easily observed as they feed on the upper surface of leaves, they mate on the leaves during spring and early summer and females oviposit on submerged stems and foliage. Larvae feed within roots and develop rapidly through the summer, they pupate within a cocoon on the outer surface of roots from August and adults eclose later in the summer; most will remain in situ to overwinter but specimens are occasionally recorded through the winter. Adults may be readily observed on foliage and they are easily swept but they fall or take flight when disturbed and so can be difficult to study, they will also need to be taken for examination as several other closely similar species are common in the same habitats and mixed colonies are common.