Discovering Hidden Biodiversity at Cutt’s Orchard, Brockweir
Findings from a report written by James McGill. Summary Report: Andy Stott. Web editing: Gill Stott
Introduction and summary
We don’t know what biodiversity we have until we look, that is the lesson. A recent survey at Cutt’s Orchard, Brockweir, uncovered 411 species of invertebrates—an impressive testament to the site’s ecological richness. The survey was undertaken by James McGill on two days in May and July 2025, with a focus on less well-known species of flies, beetles, spiders, bugs, bees, wasps and ants. Nicola Bacciu also surveyed lichens on the second visit in July, making 68 lichen records for the site. Among the hundreds of species recorded, twelve have a published conservation status, including the Near Threatened money spider Agyneta mollis (also Nationally Rare), and the provisional Red Data Book fly Cerodontha calamagrostis. At least ten species were recorded for the first time in Gloucestershire, such as the harvestman Sabacon viscayanus ramblaianus and several rare flies and spiders.
These discoveries highlight the importance of Cutt’s Orchard, and the other overlooked woodlands, unimproved grassland and small marshy areas in the locality, as valuable biodiversity assets for the county. The report also provides some specific and general guidance on management regarding the special interests found during the survey.
This article is based on the report of the survey submitted by James McGill in October 20251 with minor additions of maps and photos and some additional conclusions. The survey was funded by the Parish Grassland Project, with a contribution from the owners of Cutt’s Orchard, Andy and Gill Stott.
1 James McGill (2025) A survey of invertebrates at Cutt’s Orchard, Brockweir in 2025. Contract report to Parish Grassland Project
Site description
Cutt’s Orchard is in west Gloucestershire, approximately 1 km east of the River Wye at Brockweir. The underlying rocks are sandstones in the Brownstones and Quartz Conglomerate Formations. The site includes acid grassland on a north-west facing slope with a maximum elevation of 110 metres, sloping down to broadleaved woodland at 60 metres along a stream that drains to the south-west. The ground flora in the open on the lower slopes in one area is dominated by Bluebell and Bracken, and there are scattered open-grown Hawthorn. Two springs arise on the valley side, and there is flush vegetation within and outside the woodland. There are some veteran oaks at the bottom of the hill amongst secondary tree growth around Offa’s Dyke. The open areas, including scrub and some limited wood pasture are grazed by cattle in the late summer. Two woodland areas were fenced and grazing excluded in 2020. Broadleaved trees have been planted recently along the edges of the woodland and hedge lines.
Survey results in the different habitats
The survey explored a variety of habitats including broadleaved woodland, marshes and wet woodland, acid grassland and scrub. Each habitat contributed its own set of species, with the flush —a small, marshy area—proving especially rich, supporting over 40% of all species found. Veteran oaks, spring-line flushes and open-grown hawthorn scrub were all identified as key features supporting this diversity. The number of species, in different taxa, in each habitat type are listed in Annex 1.
1. Veteran Oaks
Among the interesting finds was a darkling beetle, Eledona agricola, its larvae feed on the fruiting body of the fungus Chicken of the Woods, which was growing on a veteran oak tree. This is one of only 531 records of the species included in the national biodiversity atlas. It has also been found in the Wye Valley woods at Piercefield Park. Also found below a veteran oak was the Brown Tree Ant, Lasius Brunneus. This species is widely distributed in southern England, particularly in the south-east, and is often associated with ancient parks and wood-pastures. It has apparently expanded its range in the west and is known from the Wye Valley.
Darkling beetle, Eledona agricola (Source: NBN Atlas)
Brown Tree ant, Lasius Brunneus (Source: BWARS)
2. Alder Woodland
Two other notable species, the leaf-beetle Apteropeda globosa and the money spider Hilaira excisa were found in the alder woodland where a small year-round spring emerges. The small dark metallic green leaf-beetle is nationally scarce with only 83 records included in the national biodiversity atlas. It feeds on mint and speedwell plants. It is likely to be under-recorded because it is very small (<3mm) and a quick jumper! The money spider is generally recorded in north and west of Great Britain in damp woodland and bog habitats and is on the edge of this distribution in the Wye Valley. It may be vulnerable to drying effects of tree felling or climate change.
3. Open Flush Marsh Area
The open flush/marsh area had a large diversity of species (166) in a very small area and it was noted that grazing in late summer had kept the flush vegetation open, maintaining niches for less vigorous plant species and some bare mud. The litter bug Ceratocombus coleoptratus found here as new to Gloucestershire is typical of damp habitats.
Pulsed grazing in the autumn is keeping the flush open which is beneficial for invertebrates by providing opportunities for less vigorous wetland plants, and an element of bare mud. Source: J. McGill
4. Grassland
107 invertebrate species were recorded from the grassland, and three had a recognised conservation status. A money spider Agyneta mollis was recorded as new to Gloucestershire, as well as the fly Phytomyza evanescens which is a leaf miner in buttercups Ranunculus. The money spider is associated with unimproved grassland and the examples here were found in a closed sward of Red Fesue and Sweet Vernal grass and in the flushed area lower down the slope amongst Greater Bird’s Foot Trefoil and Lesser Spearwort.
5. Scrubland Area
48 invertebrate species were recorded from the scrub, and two had recognised conservation status, including another money spider,Trematocephalus cristatus . This money spider is mostly found in SE England though it has recently been found elsewhere in the West Country and the Midlands. The only previous record in Gloucestershire is from nearby in the Wye Valley Gorge at Black Morgan’s Wood and it is probably under-recorded in the county. The scrub is part of the overall habitat mosaic at Cutt’s Orchard, with mature open-grown Hawthornas a particular feature.
Last but not least it was noted that the bare ground created by walkers on the Offa’s Dyke Footpath had created a habitat for three species of mining bee, as well as, two bee parasites.
(Managing Wildlife and Broader Implications on a separate post)