Framework to Survey Invertebrate Assemblages

Posted by Michael Williams on 7/01/2013

Ecosulis entered a staged tender process and was appointed through the Framework for CSM SSSI Invertebrate Assemblage Assessments by Natural England to undertake condition assessment for invertebrate assemblages as Sites of Special Scientific Interest (SSSI) features across 27 SSSIs around the UK. The contract commenced in April 2012 and is currently ongoing.

The habitats within the SSSIs that were surveyed were all Short Sward / Bare Suite types, and sites included heaths, chalk downland and coastal sites. Target groups of invertebrates are beetles Coleoptera (beetles), Aculeate Hymenoptera (ants, bees and wasps), Heteroptera (bugs), Orthoptera (grasshoppers and crickets), Diptera (flies) and Lepidoptera (butterflies and moths).

The ISIS protocol for assemblages was used to score the likelihood of any assemblage type being present within the sites. A Site Survey Brief document was completed for each site along with an assessment of the favourable conditions and a site report. Reports included species lists, a site description, notes on rare and interesting species and photographs of habitats on site.

Many of the sites surveyed had never been properly evaluated before, and this project is likely to record a large number of species that have not previously been recorded on some sites. Sampling methodology followed the guidelines from Natural England, with four 20 minute samples taken (eight samples on the larger coastal SSSIs) for each SSSI, employing the techniques of aerial/sweep netting, direct observation and ground searching. The number of species recorded per site varied, with over 80 species recorded from some sites. The majority of the field and lab work was undertaken by our in-house entomologist, with a smaller number of sites being undertaken by subcontractors whom Ecosulis has worked closely with for a number of years. Where necessary, difficult specimens were given a second opinion by other entomologists.

Noteworthy finds included the marsh fritillary butterfly (Euphydryas aurinia), protected under the Wildlife and Countryside Act 1981 (as amended) on two sites, the nationally notable violet oil beetle (Meloe violaceus) and ant Tapinoma erraticum, and the Red Data Book (Endangered) hoverfly Chrysotoxum vernale.