Saturday 27 September 2008

Wasp spider on Chudleigh Knighton heath

I recorded a wasp spider (Argiope brucennichi) on Chudleigh Knighton heath - the Devon Wildlife Trust reserve in August 2008.

This species is spreading in the UK probably as a result of climate change.

The current distribution from the National Biodiversity Network is here.

Wednesday 24 September 2008

Golden-haired Longhorn Beetle at Parke


The Golden-haired Longhorn Beetle (Leptura aurulenta) was recorded at Parke on the 15th August during an invertebrate training day I was running for a number of National Trust wardens. Two individuals were seen within 15 minutes of each other.

The Golden-haired Longhorn Beetle is a Nationally Scarce A category species (i.e. lives in fewer than 30 10km squares) which lives in broad-leaved woods and parklands. It is a local species restricted to southern parts of Cornwall and Devon and Hampshire and West Sussex.

The distribution map for the species can be viewed on the National Biodiversity Network - press here.
More details on longhorn beetles can be found in two recent issues of British Wildlife magazine. Identifacation - longhorn beetles: part 1 and 2. BW (2007) vol 18 pp406-14 & BW (2007) vol 19 pp35-43.

Thursday 18 September 2008

Kugelann's Ground Beetle – found in the Teign Valley 2008



Kugelann's Ground Beetle Poecilus kugelanni is a rare Red Data Book 1 species in the United Kingdom with records from only 25 sites since the 1800s.

It has been targeted as a species for action within the Dartmoor Biodiversity Action Plan. A couple of years ago I saw a presentation on the species which included some habitat photos from the Dart Valley where there is a strong a well researched population.

The habitat looked very similar to habitat that the National Trust manages in the Teign Valley (heathland with small rocky granite outcrops) just below Castle Drogo. I surveyed the heathland below the Castle in May this year on three separate occasions and found Kugelann's Ground Beetle on each occasion in two different 10km squares (SX78 and SX79). The area had been surveyed historically but no Kugelann's Ground Beetles were found. The population is probably a strong one as the beetles was found within minutes of arrival on all three occasions. One specimen was found within the pellet of a kestrel.

The species’ identification was confirmed by John Walters who is a national expert on the species and has carried out extensive surveys for the species in southern Britain since 2001. John has kindly supplied the following account of the species in Britain today.

“Earliest record 1911 from Newquay, Cornwall. Its historic range covers Cornwall, Devon, Dorset, Hampshire, Surrey, East and West Sussex, Middlesex, Norfolk and Nottinghamshire, with a further record from south Wales. Between 1960 and 1990 it was recorded once from the New Forest in 1970. Its status as RDB1 is a result of this lack of records but as a result of recent surveys it will probably change to RDB2. The survey work is based a study initiated as part of English Nature’s Scarce Ground Beetle Project between 2001 and 2007. As a result of these studies and other recent discoveries the beetle is currently known from 13 sites. Its present day range covers Cornwall, Devon, Dorset, Hampshire and Norfolk.”

It is always pleasing to find rare species in new location. During 2009 I will try and establish whether the species occurs on heathland further down the Teign Valley. This discovery is timely as it adds weight to our desire within the Dartmoor team to manage the areas of open heath and stop any further invasion of the heath by gorse and birch. This work will be funded by Natural England under an ESA capital project.

Monday 15 September 2008

The scaly cricket still at Branscombe

The scaly cricket (Pseudomogoplistes vicentae) is a very rare insect in the Britain – in fact it is only known from 3 sites: - Chesil Beach (Dorset), Branscombe Beach (Devon) and Marloes Sands (Pembrokeshire). It was first found on Chesil Beach in 1949, it was found at Branscombe in 1998 and in Pembrokeshire in 1999. It is a curious insect whose life cycle isn’t fully understood, it is nocturnal and lives on shingle beaches feeding on general detritus. A full account of its discovery in Britain can be found in Peter Sutton’s paper in British Wildlife magazine (1999) volume 10 pages 145-51.
In January 2007 the MSC Napoli was deliberately grounded in Lyme Bay off Branscombe following damage it suffered in a storm in Western Approaches. Few will forget the scenes of thousands of ‘wreckers’ looting the containers which came ashore on Branscombe. Once the containers stopped coming ashore and law and order was returned to the parish of Branscombe the clear up operation instigated by the Napoli’s insurers began. This involved clearing up the general rubbish and cleaning the beach of oil. All of this bode very badly for the scaly cricket living as it does in the direct impact and pollution zone.

A number of ecologists and entomologists expressed concern over the fate of the scaly cricket with many emails and phone calls ensuing. This turned into an unfortunate Chinese whispers exercise resulting in a note in British Wildlife 19 p207 stating that a healthy population of scaly crickets had survived. This was untrue – no one had seen a scaly cricket at Branscombe to my knowledge following the Napoli disaster.

As county recorder for orthoptera in Devon I set myself the goal in 2008 to try and re-find the species at Branscombe. I made my first trip in late August at dusk and after trudging a kilometre up the shingle beach it started to rain and I didn’t find anything except rock hoppers. Following a conservation with Peter Sutton, the National Scheme Organiser for Orthoptera I set 5 pitfall traps at various points on the beach towards Beer Head, baited with some cat biscuits, pieces of apple and a bit of my Cornish pasty! I returned a couple of days later to find 2 traps had been vandalised, two only contained rock hoppers but the final one contained a single adult female scaly cricket.

Although only one animal was trapped I am confident that a good population survives. Fortunately the colony has always existed at the other end of the beach from the major Napoli activity and as the 1999 British Wildlife article stresses scaly crickets can be very hard to find.

I guess that an animal that lives under the shingle and flourishes despite winter storms and moving shingle terraces was always odds on favourite to survive the Napoli. Good news nevertheless.

Adrian Colston