Rare sightings

73.010 Dewick’s Plusia, Macdunnoughia confusa – New to Ireland

The night of 7th/8th Oct 2023 was warm and overcast with moderate southerly winds emanating from the Bay of Biscay. As a birder, I associate such winds in October with the arrival to Ireland of European birds blown off course on their autumn migrations. As a very recent moth-er (I only started ‘mothing’ in June 2021), I’ve also learned that such conditions are also perfect for the potential arrival of European moths to Ireland.

Our home is situated just south of Newcastle, Co. Wicklow (O20) and lies 1.5km inland from the coastal wetlands that run south from Five-Mile-Point to Killoughter. Our garden is a little over an acre in size and, over the past ten years, we’ve planted over 250 natives trees and a wildflower meadow, as well as creating a pond. A section at the back of the garden is left totally wild with brambles, ferns and nettles. I do almost all of my trapping in our garden and, since starting to trap in June 2021, I’ve recorded approximately 400 moth species… so the effort of creating this wildlife garden has certainly paid off.

Inspired by the fact that Angus Tyner’s garden (which lies just south of our place) had become ‘Clifden Nonpareil Central’ over the previous week, I set up my Double 20W Actinic Skinner trap in the back of the garden more in hope than expectation. For good measure, I also put my first (and very basic) 20W Actinic Skinner on the front porch of the house. Often the white wall of the house can host more moths than this particular trap holds. A final check of the traps at midnight revealed my very first Merveille du Jour Griposia aprilina on the house wall. I felt that after seeing this beauty, anything else would be a bonus.

I closed up the porch trap and collected the Double 20W Skinner in darkness, early on the morning of 8th Oct (before my nemesis of our resident Robin had even stretched a wing). It was obvious that there wasn’t big number of moths in either trap. However, looking into my main trap I noted a Gold Spot Plusia festucae, a Silver Y Autographa gamma and my first Black Rustic Aporophyla nigra of the season. As it got brighter, I started extracting the egg cartons from my main trap. As I removed my 4th egg carton, I found myself looking at a moth I had never seen before.

It was Silver Y in shape but considerably smaller. The main colour was orange-brown on the head and thorax (with two distinct orange-brown ‘tufts’) and greyish-brown along the lower section of the forewing (the leading edge area) . However, the most striking feature was a narrow silver-white line which extended from the base of the forewing along the mid-forewing section before sweeping upwards into a larger ‘dog leg’ shape. Part of the upper section of the forewing was a glistening orange-brown. The crossband was greyish brown with a narrow pale grey and orange-brown edge to the tip of the forewing.

I took some record shots and placed the moth into my holding box before setting out to attempt to identify what species I had just trapped. My main resource is the Waring/Townsend/Lewington guide and, as I started checked the Silver Y-type groups, I found myself looking at Dewick’s Plusia Macdunnoughia confusa. It seemed to match what my moth was. I then checked the ‘atlas’ which revealed that Dewick’s Plusia doesn’t occur in Ireland and that, even on the southern coast of England, it is a relatively scarce European migrant species. So I counted it out of the equation and went back to the guidebook. Perhaps it was one of those small ‘gammina’ forms of Silver Y?

No matter how hard I searched, I kept coming back to Dewick’s Plusia. I then put my record shot through ‘Obsidentify’ and found myself shaking a little (a lot!) when it came back with a 100% positive identification as Dewick’s Plusia! Could it be possible that I had found such a rare moth species in our garden? Still in denial, I sent the images to Michael O’Donnell and Angus Tyner. Those few moments waiting for their reaction was like a rugby referee speaking with the TMO saying ‘the on-field decision is a Dewick’s Plusia….is there any reason why I can’t award a Dewick’s Plusia?’

The response from both came back very quickly with a huge congratulatory and excited confirmation that the moth I had in my holding box was indeed a Dewick’s Plusia! This was shortly followed by both guys messaging with a confirmation that it was a new moth species for Ireland.

Late that afternoon, I released the Dewick’s Plusia in the garden. It didn’t stay long enough to get a ‘more natural’ image as it kicked into action within seconds and headed off south. I never thought when I set out on my mothing journey that I’d record a first for Ireland. So, as mad as it might sound, watching it fly off, I thanked it for gracing me with its presence and for making 8th Oct 2023 a mothing day I will never forget.

Many thanks to both Michael and Angus for their help that morning, and to Jim Fitzharris who dropped in (twitched) to share the excitement of finding this jewel of a moth.

Eric Dempsey

73.237 Large Ranunculus, Polymixis flavicincta – new to Ireland.

On the 19th of September 2022, I made a last second change of mind to head for the coast instead of inland to do a short session. The destination was below Arklow Rock in south east Co. Wicklow on the beach below a cliff at grid reference T252706. It requires a 1.2km hike along the edge of a huge quarry and down 3/4 of the said beach! Not exactly an easy location to cart a trap or two as well!

This site was worth the effort as it was proving rather special for invertebrates with a large colony of Dark Bush Cricket Pholidoptera griseoaptera, Broom-tip Chesias rufata, L-album Wainscot Mythimna l-album, Sharp-angled Peacock Macaria alternata among many other good species. I had only been trapping this location and nearby spots around the quarry grounds for a year. The habitat is particularly rare with not only a beach below a vegetated hard rock cliff but has an embryonic sand dune also.  L-album Wainscot was my target and I got 4 very quickly on the night. There were also a small number of migrants trickling in such as Turnip Moth Agrotis segetum and Pearly Underwing Peridroma saucia and with a background sound of Dark Bush Crickets calling, this was already a very fruitful session.

At 22.00 the excitement levels were cranked up several notches. A large noctuid landed on the side of the 125MV trap which superficially looked like a large Black-banded Polymixis xanthomista. I potted it and while trying to make sense of this, another similar one landed on the sand five minutes later. This was also quickly potted.

Black-banded was very much on my mind as I had accidentally found one at Galley Head, Co. Cork in 2010 and had plans to travel to Cork to re-find it a week or two later. So I was absolutely astonished that they could possibly have turned up here on the Wicklow coast…..potentially a bit of a mega given only 4 previous (Co. Cork only) records and fairly rare and local in the UK. This pair didn’t quite fit though, lacking the dark band and although not having a ruler, seeming much larger.

While looking at the illustrations of Black-banded and Feathered Ranunculus, Polymixis lichenea in the Field Guide to the Moths of GB and Ireland, I noticed that Large Ranunculus, Polymixis flavicincta was a better fit but I knew it hadn’t been recorded in Ireland.  I had no mobile reception at the base of the cliff so couldn’t look up online photos to confirm my suspicions. At home, I was able to research further and took some wing measurements. The wing lengths of the two moths were 20 and 21mm putting them well outside the range of Feathered Ranunculus (15-18mm) and Black-banded (16-18mm). I circulated photos to some of the Irish experts but hardly anyone had experience of it. They were finally confirmed by Steve Nash of the UK in words like, “if they were taken in my garden, I would have no hesitation in calling them Large Ranunculus”. One was retained for Ken Bond to dissect and as a specimen for the Natural History Museum.

Although there were migrants on the move that night and normal wisdom would have concluded these Large Ranunculus were immigrants, I had my doubts. My suspicion was that they were of local origin given that two came within five minutes of each other to the light.  These suspicions were confirmed when I trapped a further four at the same location 24 days later and a single another week later a little inland from the beach.

The distribution in the UK is southern but does extend all the way to the Welsh coast. I can’t find any mention of any major change in either distribution or abundance so I do wonder how long this little colony has existed at Arklow or if there are in fact others yet to be discovered. It uses a wide range of foodplants and habitats so can’t see why it shouldn’t spread from here.

Christian Osthoff

30 June 2023

4.076 Etainia decentella – New to Ireland

26th September 2022, I was near John Luke Bridge, New Forge, Belfast. Off on my regular morning jaunt with our dog, Milou, we ended up on the edge of Clement Wilson Park at the John Luke Bridge crossing the River Lagan. There are three Etainia species in Great Britain, E. sericopeza (feeds on Norway Maple) which I had found earlier in 2022 as New to Ireland, E. louisella  (Field Maple) and E. decentella (Sycamore). I have been searching for louisella without any luck but at the bridge there was an opportunity to search for the much harder to find (described as near mythical by one of the leaf mine gurus!) decentella. It is thought that it is hard to find as it feeds on samaras high in the canopy, in fact unusually the adult is more frequently encountered than the mine.

The bridge offers some height and a large sycamore branch with samaras overhung the path. I almost immediately found a single mine. Despite a thorough search of the samaras I could reach I found no others.

To my eyes the mine is shorter and stockier than that formed by sericopeza. On line I could only find a very small number of images so I posted on the Leafmines Facebook page just to get confirmation which was quickly forthcoming.

Since this discovery two records of adults have come to light, one in Wicklow in 2022 and a much older record from Kildare in 2009. So this represents the first Irish record of the hard to find mine.

Dave Allen 16/02/23

Epinotia cinereana, 49.256 – New to Ireland!

49.256 Epinotia cinereana (Haworth, 1811)

Aspen, Populus tremula is not a common tree in my area but is a species which has an associated rich moth fauna. There are a couple of fairly well known Aspen stands of around 20 odd trees each in Killarney National Park, in particular one nice group at Dinis. It is the only site where I can regularly record the Seraphim Lobophora halterata, earlier in the season.

On the night of 29th July 2022 I headed down there for a short moth trapping session, a 3km cycle on the bike with my 80mv trap balancing on the crossbar! It was a “good night” weather-wise with plenty of moth activity. Peppered Moths Biston betularia and Grey Arches Polia nebulosa providing a few shocks as they came crashing in!

Around midnight I was admiring a fresh Cydia splendana when another Tortrix landed on the sheet. Clearly something I had not had before. It was quite striking, clean and monochrome. I potted it and looked it up later and felt it was a good candidate for Epinotia cinereana.  It was sent to Ken Bond who confirmed by genital dissection that it was indeed a female Epinotia cinereana, the first confirmed record in Ireland.

This is a species once considered a subspecies of Epinotia nisella, but now considered a species in its own right. It feeds on Aspen whereas E. nisella feeds on Sallows Salix sp. and there are various genital differences.

Thanks to Ken Bond for confirming the identification.

Stephen Cotter

March 2023

Epinotia cinereana – Side view
Epinotia cinereana – Top view

Phyllonorycter tristrigella – New to Ireland!

15.078 Phyllonorycter tristrigella (Haworth, 1828)

16th August 2022, Minnowburn, Belfast. Off on my regular morning jaunt with our dog, Milou we ended up by the Minnowburn stream where there is good tree cover including a couple of Wych Elms Ulmus glabra in the under-storey. I initially noticed a gallery mine (turned out to be Stigmella lemniscella – yellow larva present) but then to my astonishment a tentiform mine of a Phyllonorycter, something I had never previously seen on Wych Elm, caught my eye. There are only two options in GB noted on the leaf mining websites, P. tristrigella and P. schreberella. There are no cross-over species listed i.e. species on the “wrong” host. A quick run through the keys and checking images quickly confirmed the mine to be P tristrigella. P. schreberella forms an oval tent/blotch, often crossing veins, it is uncommon on Wych Elm and has a very southern distribution in GB. Tristrigella mines lie between veins forming a strongly contracted tube running from mid-rib to leaf edge, obvious in the attached images. There are a few strong folds on this mine which hard to capture in the image as the mine is so puckered causing them to merge. Frass was tightly packed in bottom corner of the mine. The mine was vacated. Amazingly following this discovery Eamonn O’Donnell found a long vacated mine, also on Wych Elm, in Dublin the following day!  Thanks again to CEDaR and the Environmental Recorders Group small grant. To date I have found it nowhere else despite searching.

Dave Allen 22/08/22

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