The Isles of Scilly Biodiversity Audit 2008 - Cornwall Wildlife Trust

2.2.1.20 Coleoptera - BeetlesOverviewBeetles are a large group of insects which belong tothe order Coleoptera. The beetles are one of the largestinsect orders, numbering some 3900 species in theBritish Isles. The beetles include such well-knowngroups such as ladybirds and weevils. They arecharacterised by their hard, wing cases, which may becoloured or have a metallic appearance.The beetles of the Isles of Scilly have been relativelywell-recorded, with a species list of 568 species, butsome of the records are rather old.Important AreasThe coastal areas are of importance for several rarebeetles, but the best areas within those coastal areas donot appear to have been described and published.Conservation ImportanceThere is one species on the BAP priority list:Meloe proscarabaeus black oil-beetleThere are 10 RDB species. Of the 10 species listed, themajority are of indeterminate status and the followingfour may be of most significance:Silpha obscura RDBPsylliodes hyoscanii RDBCathormiocerus maritimus RDBCathormiocerus myrmecophilus RDBThe two Cathormiocerus species of weevil may beconsidered locally important for the Isles of Scilly.Both are specialists of grazed sea-cliffs in the southwestand are threatened by cessation of coastal grazingand increased public pressure on cliff-top habitats.There is one further species of significance: Tansy leafbeetleChrysolina graminis. This is a declining specieswith the Isles of Scilly as one of the few places withpost-1980 records. The recent Atlas of the Seed & LeafBeetles of Britain and Ireland says it should be upgradedfrom Notable A to RDB status, and that ‘it shouldqualify for BAP priority status’.Trends and IssuesResearchA report should be written describing the importantareas for the beetles of conservation concern.Habitat LossThe reduction in heathland grazing has had an adverseeffect on certain coastal grasslands, which in somecases could adversely affect certain beetle species.TourismIncreased visitor numbers have led to more tramplingof certain areas and an increase in uncontrolled fires.Black oil beetle Meloe proscarabaeus. Photo: Rosemary ParslowIsles of Scilly biodiversity audit Page 33