4f4c4942-4343-5764-6473-313231383434 English Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2026-10-07T14:19:54.406Z NRW 1.0 wel utf8 British National Grid (EPSG::27700) The current status and distribution of the beetles Anthonomus conspersus, Aulacobaris lepidii and Thinobius newberyi on selected Welsh Sites of Special Scientific Interest (SSSIs) in 2018 The current status and distribution of the beetles Anthonomus conspersus, Aulacobaris lepidii and Thinobius newberyi on selected Welsh Sites of Special Scientific Interest (SSSIs) in 2018 Statws a dosbarthiad cyfredol y chwilod Anthonomus conspersus, Aulacobaris lepidii a Thinobius newberyi ar Safleoedd o Ddiddordeb Gwyddonol Arbennig (SoDdGA) dethol yng Nghymru yn 2018 2018-11-12 NRW_DS121844 http://naturalresources.wales/ The three species selected for this contract are all Individually Qualifying Features of their respective SSSIs, yet none had been recorded on those sites for at least twenty years. There is no evidence that Anthonomus conspersus or Aulacobaris lepidii had been actively searched for during the intervening period and, although some survey effort in 2004 may have resulted in records of Thinobius newberyi, this is a particularly difficult species to detect. As habitat conditions for all three species appeared to remain suitable, there was no reason to suppose that any of the populations had become extinct. Nevertheless, after such a long interval, confirmation of their continued presence was clearly desirable. The rowan weevil A. conspersus was found to be well established at Coed Boch y Rhaeadr in Migneint-Arenig-Dduallt SSSI, with adults recorded throughout the woodland and on the adjacent ffridd. Historically, the area was probably managed as pasture woodland and numerous ancient rowan trees remain scattered throughout both the denser wooded areas and the open hillside. A detailed survey of the tree resource was not possible within the time available, but a rough estimate suggests that more than 300 trees are present. A map showing the principal concentrations is provided. For at least twenty years, grazing stock has been excluded from the woodland under an agri-environment scheme, leading to an increase in birch scrub on the lower slopes. Although sufficient open areas currently remain to provide suitable habitat for A. conspersus, consideration should be given to management measures that retain these clearings within the woodland. The yellow crucifer weevil A. lepidii was recorded twice on the Dee Meanders within Afon Dyfrdwy (River Dee) SSSI during the 1990s but has not been recorded since. Five survey sites were selected from aerial photography where exposed sand and gravel deposits were clearly visible on the riverbanks, as A. lepidii breeds in the roots of crucifer species growing in sandy sediments. A further two sites identified during an earlier survey as containing potentially suitable habitat were also visited. The species was not recorded at any survey site. Vegetation succession had progressed at both previously recommended locations to such an extent that little or no exposed sand remained. Host plants were generally scarce on the other sites and, at four of the five locations, trampling by livestock was evident, with crucifer host plants heavily grazed. It is likely that A. lepidii still occurs along this stretch of river; however, disturbance to the shingle bars is a concern and consideration should be given to fencing selected areas to protect the shingle invertebrate assemblage. The shingle rove beetle T. newberyi is a feature of Gro Ty'n-yr-Helyg SSSI on the Afon Ystwyth and the Ystwyth and Rheidol Shingles & Backwaters SSSI on the Afon Rheidol. At the original site, Gro Ty'n-yr-Helyg, the river has altered its course, removing most of the former shingle bar. Suitable sediments are now deposited further downstream, although these deposits are much smaller in extent than those previously present. On the Afon Rheidol, the site from which records were obtained in the 1990s is no longer suitable, as dense willow carr has become established across the area. Attempts to access other shingle bars within the floodplain were hindered by deep water and dense scrub, while the only bar examined, at Abercwmdolau, contained sediments with a high silt content. The species is thought to require clean sand or fine gravel. Hand-searching and excavation on both rivers failed to locate the target species, but T. newberyi is notoriously difficult to detect and its absence from this survey should not be interpreted as evidence of extinction. The current condition of habitat on the Rheidol is a cause for concern, although future flood events may rework sediments and create suitable new bars. On the Ystwyth, potential sites both upstream and downstream of Ty'n-yr-Helyg should be investigated further to assess their suitability for shingle invertebrates. The three species selected for this contract are all Individually Qualifying Features of their respective SSSIs, yet none had been recorded on those sites for at least twenty years. There is no evidence that Anthonomus conspersus or Aulacobaris lepidii had been actively searched for during the intervening period and, although some survey effort in 2004 may have resulted in records of Thinobius newberyi, this is a particularly difficult species to detect. As habitat conditions for all three species appeared to remain suitable, there was no reason to suppose that any of the populations had become extinct. Nevertheless, after such a long interval, confirmation of their continued presence was clearly desirable. The rowan weevil A. conspersus was found to be well established at Coed Boch y Rhaeadr in Migneint-Arenig-Dduallt SSSI, with adults recorded throughout the woodland and on the adjacent ffridd. Historically, the area was probably managed as pasture woodland and numerous ancient rowan trees remain scattered throughout both the denser wooded areas and the open hillside. A detailed survey of the tree resource was not possible within the time available, but a rough estimate suggests that more than 300 trees are present. A map showing the principal concentrations is provided. For at least twenty years, grazing stock has been excluded from the woodland under an agri-environment scheme, leading to an increase in birch scrub on the lower slopes. Although sufficient open areas currently remain to provide suitable habitat for A. conspersus, consideration should be given to management measures that retain these clearings within the woodland. The yellow crucifer weevil A. lepidii was recorded twice on the Dee Meanders within Afon Dyfrdwy (River Dee) SSSI during the 1990s but has not been recorded since. Five survey sites were selected from aerial photography where exposed sand and gravel deposits were clearly visible on the riverbanks, as A. lepidii breeds in the roots of crucifer species growing in sandy sediments. A further two sites identified during an earlier survey as containing potentially suitable habitat were also visited. The species was not recorded at any survey site. Vegetation succession had progressed at both previously recommended locations to such an extent that little or no exposed sand remained. Host plants were generally scarce on the other sites and, at four of the five locations, trampling by livestock was evident, with crucifer host plants heavily grazed. It is likely that A. lepidii still occurs along this stretch of river; however, disturbance to the shingle bars is a concern and consideration should be given to fencing selected areas to protect the shingle invertebrate assemblage. The shingle rove beetle T. newberyi is a feature of Gro Ty'n-yr-Helyg SSSI on the Afon Ystwyth and the Ystwyth and Rheidol Shingles & Backwaters SSSI on the Afon Rheidol. At the original site, Gro Ty'n-yr-Helyg, the river has altered its course, removing most of the former shingle bar. Suitable sediments are now deposited further downstream, although these deposits are much smaller in extent than those previously present. On the Afon Rheidol, the site from which records were obtained in the 1990s is no longer suitable, as dense willow carr has become established across the area. Attempts to access other shingle bars within the floodplain were hindered by deep water and dense scrub, while the only bar examined, at Abercwmdolau, contained sediments with a high silt content. The species is thought to require clean sand or fine gravel. Hand-searching and excavation on both rivers failed to locate the target species, but T. newberyi is notoriously difficult to detect and its absence from this survey should not be interpreted as evidence of extinction. The current condition of habitat on the Rheidol is a cause for concern, although future flood events may rework sediments and create suitable new bars. On the Ystwyth, potential sites both upstream and downstream of Ty'n-yr-Helyg should be investigated further to assess their suitability for shingle invertebrates. Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Adrian Fowles Adrian Fowles, C/O Natural Resources Wales at Maes y Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk https://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Protected sites Species distribution Habitats and biotopes GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme coleoptera beetles NRW Thesaurus 2026-08-27 geonetwork.thesaurus.local.theme.converted_nrw-keywords There are no access restrictions on this data. NRW may release, publish or disseminate it freely. no limitations © CNC/NRW Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose. Attribution statement: Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. Open Government Licence English biota SeaVoX Vertical Co-ordinate Coverages 2021-01-06 Wales (WLS) -5.777741 -2.608865 51.240829 53.513067 2018-05-22 2018-08-04 The current status and distribution of the beetles Anthonomus conspersus, Aulacobaris lepidii and Thinobius newberyi on selected Welsh SSSIs in 2018 Database Unknown Species records on Welsh Invertebrate Database Documents Unknown Report as pdf format Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 This dataset has not been assessed for conformance to the referenced INSPIRE regulation. false Survey techniques for the three beetle species involved visual searches, hand-searches and substrate excavations. Survey techniques for the three beetle species involved visual searches, hand-searches and substrate excavations.