River shingle ground beetle  (Lionychus quadrillum)

Lionychus quadrillum is a rare ground beetle that is easily recognised by the yellow spots on the black wing cases or ‘elytra’ (2). The two spots closer to the head are always present, but the lower spots are sometimes completely absent or joined to the anterior spots (2).

Old records for this species are from the east, south-east, south and south-west coasts of England, and it was widely thought of as a coastal species in Britain. Many of these populations have been lost, however, and current records are known only from a handful of coastal sites in Suffolk and north Essex as well as in the south-west. More recently a number of inland populations have been discovered on four Welsh rivers (3). This beetle is widespread in continental Europe (4).

River shingle beetles inhabit exposed riverine sediments, particularly shingles, hence the name (3).

Very little is known of the ecology of this rare beetle.

Many coastal populations of this species appear to have been destroyed largely as a result of widespread habitat loss caused by building of coastal defences and other developments. River straightening or dredging is also likely to affect populations, as is the control of water levels by damming or flood defence. The spread of invasive plants such as Himalayan balsam (Impatiens glandulifera) may also cause problems (3).

A number of beetles sharing this river shingle habitat have been highlighted as priorities under the UK Biodiversity Action Plan (UK BAP). A Group Action Plan has been produced to coordinate efforts to conserve these species; this plan aims to maintain current populations. The Environment Agency, English Nature and the Countryside Council for Wales have joint-funded studies aiming to improve understanding of these species, in order to better guide their conservation (3).

Information authenticated by Dr Martin Luff of the School of Biology, University of Newcastle, with the support of the British Ecological Society:
http://www.britishecologicalsociety.org/