Marvellous Moths - Askham Bog - 16/06/2025

 

YWT Askham Bog 16/06/2025

    As we arrive at Askham Bog, the weather can only be what feels like a near perfect summer evening for moth recording - the only criticism being that it is quite clear above with only some thin, wispy clouds gracing the light pale hue of the sky. I have travelled to Askham Bog with two colleagues from my time with the RSPB, who have both recently taken an interest in moths - fab!! Our target moth is actually quite a common one - Elephant Hawk-Moth. The reason being that one of them, has never seen it in person and we all know how Elephant Hawk-Moths can be the gateway into moths for a lot of people.

    Before we get to the moths a little bit of information about Askham Bog, the set-up and some other wildlife sightings. Askham Bog is a small nature reserve, managed by Yorkshire Wildlife Trust (YWT), nestled alongside the A64 & the East Coast Mainline. Its origins - the site of an ancient lake formed some 15,000 years ago by a retreating glacier. It was the birthplace of YWT being their first reserve and is now the only surviving remnant of Ancient Peatland in Yorkshire and once described by the renowned Sir David Attenborough as a "Cathedral of Nature Conservation".

    We arrived in the early evening - 19.45 as we had decided to have a walk round the reserve to scope out the location for the evenings recording and also to see what other wildlife we could encounter. Traversing the boardwalks, we couldn't help but notice the sheer number of Common Spotted-Orchids scattered among the damp meadows.

Common Spotted-Orchid

    Down in the grasses, many of the stems were covered in "Cuckoo Spit" - a foamy, white liquid that is secreted by the nymphs of Froghoppers of which there are 10 species in the UK. Each blob of "spit" contains one of these nymphs which all in are roughly 5mm long. The most fascinating fact is how the "spit" is created - as the nymph feeds, it forces air into fluid from its anus, in turn making bubbles (Stop giggling at the back)! It definitely has nothing to do with the bird - apart from you start to see it at around the same time as Cuckoos arrive into the UK.

"Cuckoo Spit"

    As the evening progressed, the golden glow of the sun started to leech through the foliage. Out in the open areas where the tree canopy isn't as dense, our eyes are caught by the shape of a thick-bodied bird whirring across the tree tops, combined with a high-pitched call. This bird being a Woodcock. Throughout the evening we have around 20 sightings of Woodcock in total.

    We decide to set up for the evening on one of the open areas of boardwalk, where there is still water being retained amongst the reeds, despite all of the warm weather we have been having. The equipment we are using consists of a Robinson Moth Trap which houses a 125W Mercury Vapour bulb. We have a petrol generator supplying the power, a white sheet to reflect the light from - which also means we don't step on any camouflaged moths, 2 nets to carefully catch the moths as they arrive and lots of specimen pots of varying shapes and sizes depending on what type of moth we get. The trap was ran from 21:30 through to 00:30.

125W Mercury Vapour Robinson Moth Trap

    Now to look at some of the moths we got - I know that's the only reason you've made it this far!

    Our most recorded moth of the evening by far was the Straw Dot (Rivula sericealis) - Size: 13-15mm forewing. This very common & widespread resident was around constantly throughout the night with an estimated 25 being seen. Up until around the mid 70s this was actually a very rare moth for Yorkshire with only 3 records: c.1883, 1942 & 1970 before rapidly spreading. Whilst 25 of these might seem excessive - a trap in Haxby on 29/8/2008 actually held a staggering 391 of these! Straw Dots can be found in Damp Meadows & Woodland habitat with the larval foodplant being Grasses. Overall this moth has been recorded 27,615 times with 103,184 specimens from that.

Straw Dot

    Our next, most frequent visitor for the evening with 10 sightings was Brown China-mark (Elophila nymphaeata) - Size: 22-30mm Wingspan. The China-mark family differ from a lot of moths, in the fact that their larvae are entirely aquatic and spend their time feeding on water-based plants. Naturally, the species is predominantly found in larger numbers near rivers, ponds & lakes - however can be found in gardens within proximity to aquatic habitat. Overall, this moth has been recorded 2,587 times with a total specimen count of 8,448.

Brown China-mark

    The first of the new moths for me was the Obscure Wainscot (Leucania obsoleta) - Size:36-40mm Wingspan. This local resident can't quite decide whether it wants to do well or not, with annual records continually going through many peaks and troughs. In 2008 it had all but disappeared from the county before staging somewhat of a comeback over the next 9 years, with a peak of 382 specimens in 2017. It has continued to rise and fall since then with only 28 specimens recorded in 2024. Across the UK, the trends continue to vary. It has increased its overall range of where it hangs out, however in doing so seemingly has now deserted East Anglia & Lincolnshire - why? It's not like either of these places are lacking the necessary habitat. Overall in Yorkshire it has been recorded 661 times with a specimen count of 1,962 - 2 previous records at Askham Bog, both in 2023 (19th & 24th June).

Obscure Wainscot

   Then next addition to my "Life List" of moths is perhaps my favourite from the recording session. Doing everything it can to dispel those stories of how all moths are brown or beige and have nothing about them - Blotched Emerald would disagree! Blotched Emerald (Comibaena bajularia) - Size:14-17mm forewing is a local resident in Yorkshire, having reached its Northern limit for the county. The most northern record being a lone appearance at Sutton Bank on 17/07/2022. We recorded 3 specimens which is in line with the site average of 2.6 per recording session. The larval food plant for Blotched Emerald is the leaves of Oaks. Emerald species featured well on the list of recorded moths with Common Emerald 6, Large Emerald 1 and Light Emerald 4 - with all 3 being fairly common and widespread across the county. Total records for Blotched Emerald are 273, bringing 471 specimens.  

Blotched Emerald

  The penultimate moth is another that goes a long way to keep pushing back on the brown/beige argument. This moth had made its way into the trap on its arrival so we didn't find it until about 00:45 and was definitely warmly received at the end of the session as we were packing away. Peach Blossom (Thyatira batis) Size:16-19mm forewing is a stunning and unmistakable species that you can't help but just appreciate. Larval food source for Peach Blossom is Bramble. The species is fairly well distributed across the county with a rough average of around 150 specimens per year recorded since the early 2000s. Our record will be the 6th sighting at AB with 3 of those other records being within a week of this date in 2023, 2021 & 2020.

Peach Blossom

    I will round out the photo section in the only way possible, with our simple yet beautiful target species. Elephant Hawk-Moth (Deilephila elpenor) - Size:28-33mm forewing is well renowned for being a gateway into the world of moths and there really is no argument to this. With is bold, striking colours, first time viewers can't help but just appreciate them. Keen gardeners may also have their first interaction with the larvae of the EHM whilst titivating their garden, finding the chunky, "Elephants trunk" caterpillars feeding on either willow-herb or most commonly their fuchsias. Fuchsias & Honeysuckle are the plants I used to recommend to people who were desperate to find these moths in their garden. By growing both you are feeding the moth in both Larval and Adult form. Records for EHM total 15,588, providing 29,599 specimens across the county. In total 3 EHM were recorded during the session along with a singular Small Elephant Hawk-Moth.

Elephant Hawk-Moth

    Overall the 3hr session yielded 151 moths from 50 species. I will list them below in order of prevalence:

Straw Dot 25+

Brown China-mark 10

Smoky Wainscot 10

Riband Wave 6

Flame Shoulder 6

Green Carpet 6

Common Emerald 6

Variegated Golden Tortrix 5

Clouded Border 5

Barred Straw 4

Light Emerald 4

Marbled Brown 3

Common Wainscot 3

Beautiful Hook-Tip 3

Brimstone 3

Ringed China-mark 3

Blotched Emerald

Elephant Hawk-Moth 3

Common White Wave 3

Bright-Line Brown-Eye 2

White-Backed Tortrix 2

Large Yellow Underwing 2

Double Square-Spot 2

Clouded Silver 2

Small Engrailed 2

Devon Carpet 2

Drinker 2

Nematopogon swammerdamella 2

Heart & Dart 1

Poplar Grey 1

Snout 1

Marbled White Spot 1

Small Fan-Footed Wave 1

Blood-Vein 1

Miller 1

Notocelia uddmanniana 1

Celypha lacunana 1

Green Oak Tortrix 1

Obscure Wainscot 1

Marbled Minor Agg. 1

Peach Blossom 1

Green Pug 1

Large Emerald 1

Small Elephant Hawk-Moth 1

Silver-ground Carpet 1

Common Pug 1

Large Fruit-tree Tortrix 1

Common Footman 1

Chilo phragmitella 1

July Highflyer 1

If you have made it this far, thank you once again for taking the time out of your day to have a read - any suggestions on format etc are greatly appreciated.

Thanks must be added to the following organisations/websites where some of this data has been extracted:

Butterfly Conservation - Home page | Butterfly Conservation

UK Moths - UKMoths | Guide to the moths of Great Britain and Ireland

Yorkshire Moths - Yorkshire Moths - The macro and micro moths of Yorkshire.

All of the moth recorders, County Recorders, Vice County Co-ordinators and website admins who make all of this data - make sense!