Filed Club members set out on the Longstone Edge walk (D Purchase)

The Field Club outing to Longstone Edge

By Saturday 23 July it was hard to appreciate that the foregathered Buxton Field Club members had just lived through the hottest temperatures ever recorded in the history of the town. Most who had noted a precise reading on the previous Tuesday – i.e. four days earlier – had logged around 34-36 degrees Centigrade. By the time of our penultimate outing to Longstone, however, we were back in more typical summer temperatures. At least it barely rained during the walk!

This high ridge at Longstone, just to the south-east of Wardlow mires and north of both Rowland and Hassop villages, commands spectacular panoramic views both to north and south. When we arrived there were instantly ravens floating in a large family group over the southern slope, reminding us that the deep human-made cliffs of High Rake are now a great wildlife habitat for nesting birds. There were also stock doves, which probably nest there, but the highlight was a sighting of a peregrine later in the day. This scarce bird of prey may well eventually breed at the quarry, reflecting the inadvertent habitat creation that can be associated with the Peak District’s arch industrial enemy – quarrying.

There might not have been too much to detain us in the first mile of walking, but we soon reached the infilled areas around Deep Rake, where the spoil heaps are remarkably stony and infertile. These areas are now managed as part of a Peak Park-arranged higher-level Countryside Stewardship programme and they were fabulous for wildlife. It was wonderful to see a field, that closer to Buxton would have otherwise held 200 sheep, containing just 3 solitary beasts!  The high summer temperature had burnt off almost all of the orchids that we might have expected in another year. Even so, this patch was fabulous for flowers and insects. Soon the BFC crocodile was moving in a much slower and meandering format and I calculated that in the course of the whole walk we averaged roughly a mile every 100 minutes.

Woolly thistle was arguably the highlight and centrepiece for our excursion. Longstone is really a stronghold for the plant. They were easily the largest flowered thistle that we saw and the flowers - usually only 1-2 per plant was actually in bloom at this state of the season - were huge draws for nectaring insects and especially bumblebees if which we recorded at least seven species. (M Cocker)

Flowers included lots of knapweed, eyebright, various hawkweeds and thyme-leaved sandwort. But the undoubted highlight of the day were the six thistle species, including carline, spear, musk and marsh thistles. The most exciting were surely the woolly thistles, both for their spectacular flowers but also for the abundant insects that they attracted. As usual the key experts were in much demand. In fact, the routine cry of ‘JONATHAN!’ was a good indication that something rather wonderful and unexpected had been found and we needed someone like Jonny Mortin to give it a name.

Jonathan! was the most frequent hue-and-cry of the day, when something rather wonderful had been found. We needed his expertise to attach a name to a sighting. Here is Jonathan (Mortin) in customary pose, inspecting the contents of his sweep net. (M Cocker)
The woolly thistle enjoyed by the majority of members featured this solitary caterpillar which has been identified as a painted lady, final instar. For some of us presumably the first time that we had seen this butterfly in larval form. (M Cocker)

One of the more interesting flies we scrutinised was a beautiful green-eyed, speckled, presumably gall-forming, thistle specialist called Terrelia longicauda. Another great beasty that we were later able to verify was a small solitary bee called spiny mason bee, Osmia spinosus. This little fellow has gorgeous speckled or marbled blue eyes and a bright furry orange underside to its abdomen in the female. This is its so-called scopa, a pollen-gathering apparatus, whose fruits they take back to a solitary nest which, with this species, is located inside an abandoned snail shell. She then provisions her young in cells and leaves them to brood off this food source. The only other Derbyshire record appears to be one near Wirksworth in 2019.

Many people collected to inspect the woolly thistles, whose flowers are huge well-armoured magenta spheres with a curious ‘candyfloss’ webbing around the bloom (technically I think the flower is called an involucre) and hence the name ‘woolly’. There were generally only 1-2 emerged flowers per plant but the whole spike, with its complex, architecture, was full of invertebrates including furrow-web orb weaver spider Larinioides cornutus, shield bugs, a painted lady caterpillar, the Terrelia fruit flies, bumblebees of at least five species including the hill cuckoo bee Bombus rupestris and spittle bugs, In fact the thistles were notable for being an ecosystem unto themselves.

We were normally an evenly spread and somewhat anarchic caravan for much of the walk but there was one wonderful moment when the BFC was caught in collective worship. Around a magnificent spike of woolly thistle, with its entire ecosystem of associated invertebrates. (M Cocker)
One of the day's highlights was a species called Hill or Red-tailed Cuckoo Bee Bombus rupestris. Each of our six common bumblebees has an associated cuckoo. These parasitic siblings enter and neutralise the rightful queen of a bumblebee colony (in the case of Bombus rupestris its host is Bombus lapidarius, the Red-tailed Bumblebee) and then hatch a single generation of sexually reproductive offspring, which are reared by the host workers. (M Cocker)
One of the other highlights was this rather beautiful fly called Terrelia longicauda or Greater Fruitfly. It is probably a gall-forming fly that specialises in thistles. The long ovipositor at the rear of this female is used to insert eggs inside the hollow stem parts of the plant and trigger gall formation. (M Cocker)

After lunch we meandered around the rather burnt-out southern slope of the ridge, but it is notable for being a lovely mosaic of hawthorn scrub and open grassy flower-rich glades. Maybe this area could form the basis of an earlier-summer follow-up visit in the future. All in all, we had a great day and after more 6 hours of meandering we had all managed to cover three miles! 

Here finally is the spiny mason bee mentioned in the text which was as far as we can see the second record for the county. (M Cocker)

Mark Cocker, author and naturalist




Some more photos from the walk

The woolly thistle has a beautiful spherical flowerhead. (D Purchase)
Woolly thistle in flower - a huge draw for pollinators. (D Purchase)
The Field Club walkers at Deep Rake on Longstone Edge (D Purchase)
Common ed Soldier Beetles feeding on thistles at Longstone Edge (D Purchase)
Comma Butterfly, Longstone Edge (D Purchase)
Mountain Male-fern (Dryopteris oreades) showing sori (conatining spore capsules), with indusia (protective membranes) peeled back in mid-season. These are mostly confined to the inner end of the pinnules, unlike the other Male-ferns. Bipinnate ferns that grow on 'shuttlecock' form. (D Purchase)