Invertebrate Survey of Site at Weavers Hill, Staffordshire Undertaken by Richard Wright on Behalf of Apex Ecology June and July 2008
Total Page：16
File Type：pdf, Size：1020Kb
Weavers Hill Quarry, nr. Gnosall, Staffordshire Ecological Scoping and Protected Species Survey Report APPENDIX III – INVERTEBRATE SURVEY REPORT PREPARED BY RICHARD WRIGHT Invertebrate survey of site at Weavers Hill, Staffordshire undertaken by Richard Wright on behalf of Apex Ecology June and July 2008 Summary The site was visited on three occasions, during June and July. A total of 377 species were recorded. The sandhills and surrounding area were by far the most important. The adjacent field had very low diversity and while a fair number of species were recorded from the stream corridor, all but one of these were more or less common and ubiquitous species. A very few aquatic species and some associated with marsh were found in and around the pond, but again these were generally widespread and common species. It is considered that the fauna of the sandhill area, particularly the aculeate Hymenoptera, may be of county importance. Methods On each visit most of the sandhill area, around the pond and along the stream corridor were swept intensively Sample areas of the field, which was rather uniform, were also swept. Several of the oak trees in the field, together with trees on the rest of the site, were also beaten. A total of 40 pitfall traps were set on the first visit, emptied on the second and emptied and removed on the third. These were distributed in and around the edges of the sandhill area. A short visit was made 5 days before the second main visit and 20 white water traps were set. These were white plastic containers about 70 square centimeteres in surface area, partly filled with saturated salt solution. These traps were emptied on the second main visit. In addition, several species of butterfly, hoverfly and bumble bee were observed on flowers and recorded. Results A total of 377 species were recorded. This is a reasonable sample for evaluation of the site, though further species might be found if the survey were extended earlier and later in the year. A full species list can be found at the end of this report. In the case of the aculeate Hymenoptera, information about the known distribution of species in Staffordshire could be obtained from the Staffordshire Ecological Record website (www.staffs- ecology.org.uk) where online atlases are available for certain groups. This is referred to here as SER. While most of the species found can be considered more or less ubiquitous and common and are probably present in many sites in the area, a number of more interesting species and an assemblage associated with the sandy ground, were recorded. The aculeate Hymenoptera were given special attention and are discussed separately, as are the three species considered nationally scarce. Apex Ecology Limited November 2009 Report HB/091134 Weavers Hill Quarry, nr. Gnosall, Staffordshire Ecological Scoping and Protected Species Survey Report Species in relation to habitats The field and stream corridor were generally of little specific interest, producing mainly common species which are likely to be more or less ubiquitous in similar habitats locally. However, the soldier fly Vanoyia tenuicornis which is considered nationally scarce was swept from near the stream corridor and probably breeds in the stream margins. A small number of aquatic and marsh species were found in and around the pond, which contained very little water during the survey period, including very large numbers of the soldier fly Oplodontha viridula. From the trees, including the mature oaks in the field, a reasonable number of species were recorded but all are common species which are likely to be found on these tree species almost everywhere. The sandhill area was of much greater interest. The majority of the aculeate Hymenoptera were recorded only here and they are discussed later. Other species characteristic of this habitat are the beetles Agrypnus murinus, Amara tibialis, Dyschirius politus. Bledius gallicus and Adonia variegata, together with the robber fly Dysmachus trigonus. Of particular interest is the weevil Philopedon plagiatus which is not uncommon on coastal sand dunes but with few inland records (very few in the Midlands) and has specially adapted front legs for digging in sand. Nationally scarce species At the present site, three species categorised as nationally scarce “B” (Nb) were recorded. None of these appear to be very scarce and they may be liable to lose their scarce status in any future review. Adonia variegata (Coleoptera, Coccinellidae) Adonis’ Ladybird Although still classified as nationally scarce, this species is now known to be relatively common and will almost certainly lose its status at the next review. It prefers dry ground and is often found on post- industrial sites. Several specimens swept. Vanoyia tenuicornis (Diptera, Stratiomyidae) a soldier fly A wetland species, this is widespread but local through much of England and Wales. A single specimen was swept from hogweed near to the stream corridor. Nysson trimaculatus (Hymenoptera, Sphecidae) a solitary wasp This species is generally considered to be a cleptoparasite of the wasp Gorytes quadrifasciatus but this host was not recorded on the survey. It is possible that it is utilising Harpactus (formerly Gorytes) tumidus here, although the normal host may simply have been missed by the survey. Mainly found in south-east England, though recorded north to Yorkshire, this species has only one previous county record according to SER. Three specimens were found, suggesting a good population, which makes the apparent absence of the normal host rather surprising. It should be noted that the Bee Wolf Philanthus triangulum is still officially a Red Data Book species, but as it has now spread widely through England it no longer deserves any status as a scarce species. Apex Ecology Limited November 2009 Report HB/091134 Weavers Hill Quarry, nr. Gnosall, Staffordshire Ecological Scoping and Protected Species Survey Report Aculeate Hymenoptera The site was originally noted as of potential interest for aculeate Hymenoptera (bees, wasps and ants). Particular attention was given to the recording of these species, especially those nesting in the ground, though some species which generally nest in dead wood etc were also recorded. A total of 37 species of aculeate Hymenoptera were recorded. Of these, the ants and social bees and wasps are all widespread and common species, while some of the Sphecidae species are not ground- nesting. These species are not considered further. This leaves 20 species of ground-nesting solitary bees and wasps which are listed in the following table. The column headed “Staffs 10km” gives the number of OS grid 10 kilometre squares from which each species has been recorded according to the SER website. * species cleptoparasitic on other species Staffs 10km Apidae Andrena scotica 13 Colletes daviesianus 5 Epeolus variegatus * 2 Halictus tumulorum 10 Lasioglossum calceatum 10 Lasioglossum morio 5 Lasioglossum villosulum 10 Chrysididae Hedychridium ardens * 2 Pompilidae Anoplius nigerrimus 5 Arachnospila anceps 4 Arachnospila spissa 6 Sphecidae Cerceris rybyensis 4 Crabro cribrarius 8 Crossocerus wesmaeli 4 Harpactus (=Gorytes) tumidus 3 Mellinus arvensis 11 Nysson trimaculatus* 1 Oxybelus uniglumis 8 Philanthus triangulum 3 Tachysphex pompiliformis 4 As can be seen, while several of the species are rather common in the county. others appear to be rather rarely recorded. Some can be found in a variety of habitats and are not particularly associated with sandy ground, but others are more confined to this habitat. Those most specific to sandy ground are the sphecid wasps and the two Arachnospila species in the Pompilidae. By far the most abundant species was Oxybelus uniglumis which is usually common to abundant in most sandy sites and obviously has a colony of hundeds, if not thousands, of individuals here, while Tachysphex pompiliformis and Cerceris rybyensis were also common. Harpactus tumidus was apparently slightly scarcer, but still a number of specimens were found. The other species were less common, being recorded only in ones and twos. The bees were noticeably scarce, with the exception of the bumble bees. However, the author has noted a great dearth of soiltary bees in the West Midlands during 2008, in contrast to south-east England where numbers seem normal. This is almost certainly a result of the very wet and cold season during Apex Ecology Limited November 2009 Report HB/091134 Weavers Hill Quarry, nr. Gnosall, Staffordshire Ecological Scoping and Protected Species Survey Report 2007 which seems to have severely depressed bee numbers in those areas worst affected. For this reason, assessment of the bee fauna during 2008 should be treated with reservations and the wasps would appear to be more useful for site evaluation. In general, the site was found to be of some interest for aculeate Hymenoptera, with by far the most important habitat being the sandy ground where large populations of certain species were found together with a good overall diversity. Mitigation While this site may not be of exceptional importance, a comparison of the aculeate Hymenoptera recorded with the records shown on the SER wesbite, suggests that it is likely to be of county importance, in particular taking into account that 2008 was a very poor year for bees. In addition a number of other species, particularly beetles, were found associated with the sandhill area. The other habitats were generally not found to hold any species of particular interest. Ideally, the sandhill area should be retained, at least in part. Should this not be possible, then substitute areas should be created. These should be in total area comparable to or larger than the existing hills, not shaded by trees or bushes and with substantial south-facing slopes. Ideally the profile should include a variety of slopes, from vertical to gentle, and the top should be more or less flat. Most importantly, at least the upper 50 cms should be of sandy texture.