Ben Locke

There are many flowers that look like Dandelions to the non-specialist. This key by Tim Rich will help you sort them out. He provided it as an introduction to a workshop on the genus Hieracium (Hawkweeds) given in Painswick on 9 June 2024 where his Key to Hawkweeds in Gloucestershire (available as number 43 in The Gloucestershire Naturalist series) was presented.

Several of us have noted unusual defoliation, especially of willow trees, in the Severn Vale recently. The trees look as though they have almost entirely lost their leaves, as if winter is approaching. We have never noticed such extreme loss of leaves in previous years, so it seems to be an exceptional phenomenon this year. We first noticed this at the Gloucestershire Wildlife Trust’s Ashleworth Ham reserve, where Richard Humphreys has taken a series of photographs. It is clear that the outbreak is caused by the Willow Ermine Moth, which leaves webs containing caterpillars on the trees.

Rob Homan, the East Gloucestershire Moth Recorder for Vice-County 33 (East Gloucestershire) comments: “It really is an extraordinary phenomenon”. He confirms that the occurrence seems to be much heavier than usual, and notes that the same phenomenon has been noted on spindle trees.  He has provided a map showing the distribution of adult Willow Ermine moths in Gloucestershire (green dots) and the distribution of larval webs (red dots). All records up to 2023 are included. The contrast in the two patterns is marked. Note the rogue web in Cheltenham, seen last year, but not seen at that location this month.

He adds: “I have been in contact with the Worcs moth recorder – plenty of webs as is normal along the Severn and Teme valleys, but no records for 2024 for defoliation. Nothing of note has been added to iRecord for the species.”

Further searches have recorded intensive occurrences of moth webs in a variety of sites across the county, in particular at Coombe Hill, along the Leadon, and on the Avon north of Tewkesbury, mainly on willows but also on spindle trees (as far south as Frampton).    

This is a preliminary note to make GNS members aware of the numbers of Ermine Moths this year, and to appeal for further information. We may be able to present a more complete account of this year’s observations later in the year.

Meanwhile, the following note from May 2014 on Butterfly Conservation’s website may provide some useful background:

“At this time of year we often receive reports of ghostly silken webbing covering sections of hedgerows and, on occasions, individual trees. Although it can look rather sinister, don’t be alarmed. The most likely culprit is a harmless caterpillar.

“Webs have already been seen in parts of Dorset in the last week or so. These striking and obvious webs hide hundreds and sometimes tens of thousands of caterpillars of a group of moths called the Small Ermine moths. There are eight species in this group, although only the Orchard Ermine Yponomeuta padella, Spindle Ermine Y. cagnagella and Bird-cherry Ermine Y. evonymella tend to produce such extensive webbing, the former mainly on blackthorn and hawthorn, the others on spindle and bird-cherry respectively. The Bird-cherry Ermine tends to have a more northern distribution compared to the other two and occasionally whole trees can be covered by their webs, the leaves stripped bare giving the tree an eerie appearance. Sometimes these webs are so extensive that they can cover nearby objects such as benches, bicycles and gravestones.

“Why do these species spin these webs and live together in such large numbers? It’s a successful evolutionary strategy, providing protection from predators through safety in numbers. However, numbers are hard to hide and hence the production of the silken webbing.

 
“These webs and caterpillars are harmless and usually last from May to June. The webs slowly disappear over the summer and typically the hedgerow shrubs/trees recover. The adult moths fly later in summer and all look superficially similar, being white or greyish with many small black dots, hence the ermine name.

“Ermine moth webs should not be confused with other web-forming larvae, which can be found around the same time, although these nests tend not to be so extensive and the caterpillars of most are hairy. Nests could belong to the nationally scarce Small Eggar Eriogaster lanestris, whose webs can reach the size of a small football; the declining Lackey Malacosoma neustria, with their striking stripy caterpillars; the Brown-tail Euproctis chrysorrhoea, which is expanding its range; and the introduced Oak Processionary Thaumetopoea processionea. The caterpillars of the latter two have urticating hairs, i.e. these can cause rashes, and because of this we advise that all hairy caterpillars and webs should be avoided and not handled.”

Mark Parsons
Head of Moth Conservation

Stephen French adds…

“Yes, I’ve witnessed the evidence around Ashleworth and Tirley, where I often walk. Both Spindle and Willow Ermine are having a “good” year – if that’s the right term!

It’s certainly the most noticeable outbreak of Willow I have ever seen. Even some of the tree trunks are totally clad in the webs.

There is normally no lasting damage to the trees – we will have to wait and see whether the sheer scale of things this year changes that. As to why they are so numerous, I have no idea (Climate? Lack of predators?).

As Robert says, the adult moths will be on the wing soon, so we can monitor how the trees recover (although we may have to wait until next year now).

I’m doing some targeted moth recording/trapping at the nearby Hasfield Estate. It will be interesting to see if numbers of the adult moths reflect the dramatic increase in the larval stage.”

Two new special editions of The Gloucestershire Naturalist will soon be available, TGN 42 on the Landscape and Landforms of the Cotswolds and TGN 43, a Key to the Hawkweeds are likely to be of limited interest, so to avoid wastage, will only be available to those members requesting copies. Full details and order forms are on the flyer which can be downloaded and printed using the link below. Please note, non-members and digital only members will be required to pay £9.00 per copy (P&P included).

On 21 May (this year coinciding with Biodiversity Week) ten GNS members attended what has now become an annual evening field meeting in early summer at the Gloucestershire Wildlife Trust reserve at Coombe Hill. The aim was to look at breeding waterbirds and to note any other birds that might come to roost on the scrapes in the evening. After a very wet winter and spring, with almost permanent flooding from late October until mid-April, many of the meadows were still very damp, often with a mat of dying vegetation preventing normal spring flower growth – reminiscent of the historic July 2007 floods.

The evening timing meant that there was only limited birdsong along the towpath, though Sedge and Reed Warblers, Blackcap and Lesser Whitethroats, Chiffchaff and Reed Bunting were all heard; rather surprisingly, there was no Cuckoo song, though this species has been heard by day on the reserve. While walking along the towpath, we met a group of very young boy and girl scouts in full uniform who said they had enjoyed their visit and seen lots of swans.

From the hide overlooking the scrapes we too saw up to 30 Swans, mostly immature non-breeding birds that have concentrated here for the summer: a swan nest below the boardwalk appeared to have been abandoned. At least five broods of Mallard ducklings (some of them nearly full-grown, so the eggs must have been laid early on when the floods were still high, perhaps in nests in the boles of willows and other trees), and broods of very young Coot were seen. Because of the very wet conditions, wader nests were late: a single Oystercatcher was incubating in a determined way; probably two pairs of Avocets (though hard to be sure, as they often settle on the islands on what look like nests, when in fact they are just resting); a single pair of Little Ringed Plovers; Lapwings were mainly nesting on a barley field; Redshanks were present and noisy with breeding calls but may not yet have settled down to lay eggs; just before dusk, four adult Curlews flew in, two pairs, one of them carrying rings that showed it to be one of the birds raised in an incubator from eggs (“head-started”) at Slimbridge in 2019 and now nesting nearby; their arrival was not a good sign, since if they had had an active nest, they should have been incubating the eggs; indeed it was later confirmed by the WWT team studying Curlews in the Severn and Avon Vales that the nest had failed today.

Also present were an immature Great White Egret, and several Grey Herons, some of them immatures, just flying, from a nearby heronry.

No sign of migrant waders like Greenshank, which may well be passing through on their way to Arctic breeding grounds as this time of year, but – as agreed by the members who took part – a magical experience at this time of year producing a feeling of calm serenity.

There was also a good display of Tiger Sawgill fungus (Lentinus tigrinus), an uncommon find in Britain, growing here on the waterlogged rotting branches of willow.

by Alan Waterman

Weather is always an important factor and, in the lead up to this meeting it had not been good. We met in the Golf Club Carpark and even there the views are quite spectacular but also give you a good indication of the weather to come. It was quite cloudy and was cold and very windy. Thus, I put on two
extra layers, one to keep warm and one to keep dry.

Giles Alder was the leader he is the warden working for Cleeve Common Trust providing conservation advice, and working with volunteers on conservation and wildlife monitoring projects. He welcomed the small group who had braved the conditions and after negotiating the Car park ticket machine we eventually set off. We had already spotted two Swallows and a Kestrel from the car park.

The first 10 minutes was up and exposed, but Giles had said it would lead us to a more sheltered area, he was right and thank goodness as it was quite bitter to start with. Giles pointed out the rare Purple Milk Vetch which likes the short cropped grass, in April it was not in flower, a bit latter we did see numerous Early Purple Orchids and they were in flower. There were good views of Sky Larks and Meadow Pipits in this area. We also had a look for Adders which could have been out as there was some sunshine and in the sheltered areas where we had headed for it was possible.

Largely it was a bird watching meeting and it had been timed to give us a chance at Ring Ouzels, Giles of course knew the best areas. He said someone had posted a shot with 5 birds all together on FB recently, It was pointed out that with Photoshop anything can be arranged now a days. We saw a good range of
birds, and many were in full song. Lots of Willow Warblers and some Chiffchaffs, also Blackcap, Red Kites and a Buzzard, a particularly nice Goldfinch with a beak full of white sheep’s wool. And then a little distant but not too far off was what we were all hoping for the Ring Ouzel. This was a female so only just a slight lightening of the plumage on the breast not the more obvious white as shown by the male. This one had a peculiar white spot on one side of its head. Those of us with cameras did snap away but the distance was a bit too far, although Giles said it was not as distant as they often are. We followed a route round, and the sun came out more and more and the two layers I had on by that stage seemed a bit excessive. The day warming up had the advantage of bringing out some Adders and we saw three also three slowworms. Along the final stretch we also saw Stone chats.

Many thanks to Giles, an excellent guide and he is also leading another meeting for us on Monday 17th June at Tewkesbury Nature Reserve.

Pasqueflower (Pulsatilla vulgaris), a rare member of the buttercup family, is just coming into bloom. It still can be seen on a few sunny grasslands on thin soils in the Cotswolds, attracting visitors from far away, this time Chris Heath while he was back on holiday from his job in Zambia. Pasqueflower means Easter Flower but with Easter so early they took some finding, even on this well-known site on the steep banks of Barnsley Warren. In early summer the purple petals are replaced by attractive feathery seed heads.

Good weather and a nice sized group, we were lucky to have some experts on hand so that a good range of species
could be identified. With one exception(reptiles) we managed to spot representatives of all the major groups.
On the botanical side we were able to distinguish between Evernia and Ramalina, both are similar lichens and we
even found the two species on the same twig making comparison more easy. Another pair of similar looking
lichens were Parmelia sulcata and Flavoparmelia caperata, the former being bluer green and the later more apple
green. Fungi were not surprisingly few and far between but a large though ageing specimen of the yellow Witch’s
Butter fungus Tremella mesenterica was found close to the top of Crabtree Hill. Also, a slime mould was found,
pink and globular it was not positively identified at the time but was most likely Lycogala epidendum sometimes
known as Wolfs Milk. The conifers were well represented and perhaps the most notable were the Larches (our
deciduous evergreen!) these were just coming into leaf. Then it was a matter of deciding which species of Larch,
European or Japanese or even the hybrid, examples of both were found. Towards the end of the meeting, we
found some Horsetails just poking their heads skywards and in terms of flowering plant there was a reasonable mix
but very few were in flower. Close to the carpark there was quite a lot of Wood-sorrel which is Oxalis, and further
round we saw Sheep’s Sorrel which is Rumex. The Wood-sorrel was in flower but perhaps more impressive than its
white nodding flower heads were the bright green, acid green leaves, the Sheep’s Sorrel was not in flower, another
month or so before its dotty red flowers appear.

In the animal kingdom we managed a few invertebrates including a deceased dung beetle, a mix of bees feeding
on a willow species that was in flower and one Peacock Butterfly that was enjoying the sun.

There were a lot of tadpoles in a stream the flows along the lower section of Crabtree hill, it was agreed that they
seemed to be a quite an advanced stage for the time of year, not quite getting their back legs but not far off, just
as well because the water course they were living in is not permanent and is normally dry in the summer. Whether
they were destined to become frogs or toads, the group had mixed views on that.

No reptiles though the weather was warm enough to bring out a lizard or adder, but none were spotted.

Birds were not in great evidence but with about 18 keen pairs of eyes on the lookout we did manage a reasonable
list but nothing that exciting. Mike Daw keeps a mental note of what is seen and supplied me with this list:
Great Tit, Long-tailed, Tit, Blue Tit, Coal Tit, Nuthatch, Robin, Wren, Siskin, Chaffinch, Chiffchaff,
Treecreeper, Goldcrest, Blackbird, Mandarin Duck, Mallard, Canada Goose, Raven, Goshawk, Buzzard.

Before the meeting commenced at 10.30am there were a couple of Carion Crows around the car park and on the
way round some members with good hearing picked out a Blackcap singing along with Woodpigeon and Mistle
Thrush.

We did see about 4/5 young Fallow deer running across the path and they successfully jumped the fence that
surrounds the site, no signs of cattle or ponies on this visit. Plenty of evidence though of Wild Boar both their
digging and their droppings.

Thanks to all who attended and the expert knowledge that was shared with the group.

Please note that the field meeting that was due to take place at Snowshill this Sunday the 17th March has been cancelled. The location was checked in advance of the meeting and was found to be very muddy to the point of being dangerous. It will be rescheduled for a later date and hopefully better conditions.

Sunday 25th and it was time to ID some Conifers, lead by Clare and Mark Kitchen, quite a task as 36 keen
Gymnologists turned up. Is there such a word? Well, if you can have Bryologists then why not
Gymnologists?

We made a start with the Monkey Puzzle Tree, or Chilean Pine, which we all knew but could we key it
out in a proper scientific way. It proved somewhat of a challenge as some of the questions were a bit
obscure and some of the terminology had to be explained to some of the onlookers. Eventually we got
there albeit, perhaps with some help because we knew where we wanted to end up.

Subsequent trees were less of a problem as folks became more used to the questions being posed in the
key. Bit by bit we made our way round the Arboretum stopping at selected trees to work our way
through the key which by now was becoming more and more familiar.

Possibly 36 was a tad too many but it showed the interest in this difficult group of plants and maybe
future visits would be in order but with numbers restricted to no more than 20.

The phrase good weather for ducks could be adapted to good weather for mosses, especially as to
proliferate they need water so their antherozoids can swim, sperm like, to meet up with the ovule and
consummate their arrival by producing the diploid sporophyte phase of their lives and their next
generation.

An so it was on Thursday when a small group of GNS members were lead round Chedworth woods close
to the Roman villa by Pete Martin. Pete is joint organiser for the Gloucestershire branch of the British
Bryological Association but more to the point he is passionate about mosses and liverworts, and why
not? And has an amazing in depth knowledge so not only can he identify most of them he can also tell
you something about their life style, habitat preferences and all sorts of other interesting facts. Did you
know that the leafy liverwort Lophocolea smells strongly of camphor, moth balls?

The group was blessed by a short break in the rain we started off just after 10.00am as the rain abated
and progressed up a steep ish path skirting the edge of the Roman villa site, the path was running with
water and was more or less a stream. The mosses were observed using hand lenses and some were
rendered difficult to ID due to being saturated with rain water, great for the antherozoids on their way
to potential married bliss but difficult for Bryologists to make out the finer details of moss leaf
morphology.

The Bryophytes were subdivided into 4 broad groups, Mosses growing upright, mosses that are more
horizontal and feathery, Liverworts that are leafy and Liverworts that are thallose. Not perhaps 100%
scientific but easier to understand. We found representatives of all 4 groups with the feathery mosses
predominating.

Lunch was taken at around 1.30pm and the first drops of rain were then felt. This was in the vicinity of
an old railway line and tunnel, This, we then followed back to the car park stopping at times to observe
various species that were here growing on the limestone rocks that were exposed from the cutting of
the old rail line.

A lot of species were identified, too many to list here but the illustrated ones are in order of appearance.
Zygodon viridissimus
Plagiochila asplenoides
Plagiomnium undulatum
Homalothecium sericeum
Dicranum scoparium
Pellia endiviifolia
Radula complanate
Hylocomiadelphus triquetrus