Rove beetle  (Thinobius newberyi)

Classified as Indeterminate and endemic in Great Britain (2).

Thinobius newberyi is a small rove beetle. Its pale colouration and small eyes reflect that it spends much of its time buried in gravel (1). The family of rove beetles (Staphylinidae) are characterised by their very short wing cases, known as elytra. The hindwings are folded beneath the elytra, and the elongated abdomen is exposed (3).

This beetle appears to be endemic to Britain (found no where else in the world). It was first discovered in 1907 at Great Salked in Cumbria and was later discovered near Aviemore in Inverness (1). Recent records are from the banks of the Rivers Tywi, Rheidol and Ystwyth in Wales. The small size and subterranean habits of this species have probably led to it being widely overlooked. Although it has not yet been discovered in mainland Europe, it is thought that targeted surveys will find the species (2).

This tiny beetle is associated with shingle banks at the margins of clean streams and rivers (2) (1).

Very little is known of the biology of this beetle. It is thought to feed on decaying plant material and algae, like other members of the genusThinobius (2). It is largely subterranean, very rarely being seen on the surface (2). Adults have been collected in May and from July to September (1).

Like other beetles associated with river shingle, the habitat of this species is likely to be damaged by a range of factors, including river straightening and dredging, control of the flow rate caused by damming or flood defence schemes, trampling by livestock, and the spread of the invasive plant Himalayan balsam (Impatiens glandulifera), which spreads rapidly and aggressively competes with native species (2).

A number of beetles sharing this river shingle habitat have been highlighted as priority species under the UK Biodiversity Action Plan (UK BAP). A Group Action Plan has been produced to coordinate efforts to conserve these beetles. 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 (2).

• Abdomen: in arthropods (crustaceans, insects and arachnids) the abdomen is the hind region of the body, which is usually segmented to a degree (but not visibly in most spiders). In crustacea (e.g. crabs) some of the limbs attach to the abdomen; in insects the limbs are attached to the thorax (the part of the body nearest to the head) and not the abdomen. In vertebrates the abdomen is the part of the body that contains the internal organs (except the heart and lungs).
• Elytra: in beetles and earwigs, the hard fore wings. They are held aloft when the insect flies, and are often coloured or patterned.
• Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
• Genus: a category used in taxonomy, which is below ‘family’ and above ‘species’. A genus tends to contain species that have characteristics in common. The genus forms the first part of a ‘binomial’ Latin species name; the second part is the specific name.

1. National Biodiversity Network Species Dictionary (September 2003): http://www.nhm.ac.uk/nbn/
2. UK BAP Grouped Action Plan for river shingle beetles (September 2003): http://www.ukbap.org.uk
3. Harde, K. W. (2000) A field guide in colour to beetles. Silverdale Books, Leicester.