Elateridae of the British Isles

Hypnoidus riparius (Fabricius, 1793)

Size – 5.5-7mm

Description – A more rounded species with black pronotum and elytra and only a scattered covering of hairs. This species can appear rather metallic. Strong ridges running down the length of the elytra. The legs are much a light-mid brown colour and the antennae are around the length of the head and pronotum.

National Biodiversity Network map showing the distribution of Hypnoidus riparius across Britain and Ireland.

British and Irish distribution of Hypnoidus riparius (Fabricius, 1792) based on records held by the National Biodiversity Network.

Distribution data supplied by:

  • National Trust
  • Royal Horticultural Society
  • Lothian Wildlife Information Centre
  • Countryside Council for Wales
  • Highland Biological Recording Group
  • North East Scotland Biological Records Centre
  • Countryside Council for Wales
  • Balfour-Browne Club
  • Natural England
  • Leicestershire Environmental Resources Centre
  • National Trust for Scotland (staff)
  • Staffordshire Ecological Record

Distribution – Predominantly a northern and western species, it occurs fairly commonly in the north-west of England into southern Scotland and north-west Scotland and less commonly in Wales. There are scattered records from the south and Midlands, with many pre-1950.

Biology – Larvae develop in soil, where they are considered pests in some parts of the world. Imagos are semi-aquatic, being found underneath stones at the edges of streams, rivers and lakes.

Habitat -  Predominantly montane watercourses including streams, rivers and lakes. Also in more lowland areas in southern England. On the continent this species has been documented as occurring up to altitudes of 400m in north facing valleys.

Photo by K.V. Makarov courtesy of www.zin.ru/Animalia/Coleoptera

Photo by K.V. Makarov courtesy of www.zin.ru/Animalia/Coleoptera