Late summer and early autumn, is the flight season for the catocalid moths – the underwings. These large, attractive moths are mostly found in old woodlands in the south of England and can be difficult to see. They don’t reliably come to light traps but they do seem to have a weakness for sugar. ‘Sugaring’ is an old-school method of attracting moths that has become less fashionable in these days of UV lights and pheromone lures but in the right place at the right time, it can be very productive. So, armed with my deadly homebrewed ‘Moth Jam’, August is the time when I venture out into the woods to see if I can attract these elusive insects.
The 3rd of August finds me in a Hampshire wood with my good friend Ken. Our targets for the evening are the Light and Dark Crimson Underwings (C.promissa & C.sponsa) that are both present in these old oak woodlands. At dusk we find a suitable clearing amongst a few big old oaks and deploy the ‘magic moth jam’ on a few likely trunks. With nightjars and tawny owls providing the soundtrack, we retire to our camping chairs for a cheeky bottle of ale and chat while we wait. We walk a couple of fruitless rounds of our chosen trees and begin to worry that we may be too early for the emergence of our quarry. However, after an hour or so Ken notices something on one of the trunks so we approach cautiously with torchlight. The first Catocalid of the season was here before us, an absolutely pristine Light Crimson Underwing (C.promissa) eagerly lapping up the sugary fluid. We took a few pictures and retired to give it some peace. A short time passed before a second Light Crimson Underwing appeared, again fresh and pristine so we concluded we had timed our visit to coincide with the emergence of this rare and beautiful sprite of the ancient southern oakwoods. We tempted nothing else that evening but retired happy that we had seen one of our targets.
On the 10th of August I ventured out into my local Surrey woodland where I knew there were three species of underwings resident. They are the Dark Crimson Underwing (C.sponsa) the Red Underwing (C.nupta) and the much sought after Clifden Nonpareil (C.fraxini) which is re-establishing itself in the South after an absence of many years. I sugared along a ride that I knew well from previous years and retired to set my light trap in a different area. I returned to the sugar a half hour after dusk and found that 2 Dark Crimson Underwings were already in attendance. This species has recently become established in Surrey and appears to be spreading form it’s historical range in the New Forest area of Hants. In all, 4 Dark Crimsons were recorded this evening but there was no sign of the more common Red Underwing and it was still very early for Clifden Nonpareil which was probably yet to emerge.
On the morning of 12th August I got a call from my friend Bob Arnfield with the news that he had trapped the extremely rare Oak Yellow Underwing (C.nymphagoga) that morning in his garden in Putney. This is a moth with only 10 or so records in the UK so naturally I was keen to see it and duly called round for a viewing with tea and biscuits thrown in. Interestingly there are a couple of other records fairly close proximity in Surrey and Buckingham Palace Garden, which does raise the possibility that this southern European species may be establishing a presence in the London area. So maybe one to look out for in future years. Many thanks go to Bob for sharing this uber rare moth and his biscuits!
The 22nd August found my partner and I staying a few days in rural Dorset to celebrate her birthday. Not one to miss a moth-ing opportunity, I had plans to see if I could lure another extremely rare underwing. There have, to date, been 30 or so UK records of the Rosy underwing (C.electa), mostly coastal migrants but with a noticeable concentration of recent sightings in south Dorset. The assumption is that this is another European species that may have gained a small foothold in the UK. As I was in the area for a few days but with no expectation of success, I decided to try sugaring for it. Due to incredibly slow service at our pub dinner that evening it was totally dark before I arrived at my chosen location. It was difficult to find a likely spot in the dark so I settled on some trees by the road adjacent to a wood. I retired to the car for half an hour before returning to the farthest sugared tree in the pitch dark. Upon raising my torch I could immediately see an underwing gorging itself. I was too far away to identify it at this point but it was large and I was very excited. I assumed it must be the relatively common Red Underwing and approached slowly being careful not to spook the moth with the torchlight. At a few metres distance, I could make out the pattern on the forewing, the deep fingers in the outer central crossband were easily apparent. I was looking at a Rosy Underwing! I really couldn’t believe my luck. I knew I might lure this species in Dorset but had no expectations whatsoever of actually seeing it. I managed a few pictures before the moth became spooked. I flew from the tree and briefly alighted in a small bush before disappearing into the night. I was utterly elated and flushed with my success returned to the cottage for a good night’s sleep with a smile on my face.
On the 25th of August I was back in my local Surrey wood with my friend Chris Turner who was keen to see a few underwings. We went through the usual routine of deploying the ‘moth jam’ on trees along my favoured ride as well as another area adjacent to a stand of mature Aspen. The first round of sugared trees resulted in a few Dark Crimson Underwings along with several Peach Blossoms and a few Oak Lutestrings, not bad. Better was to come though. We returned to the Aspen stand and from a distance we could see a very large pale moth on the tree trunk. I knew immediately what it was and told Chris that I thought his luck was in. We approached cautiously and approached to within a metre of an absolutely pristine Clifden Nonpareil (C.fraxini). The Blue Underwing that had become extinct in Britain before re-establishing itself in recent years was here in front of us. This species breeds on Aspen and poplars so our choice of location had paid off. While watching this sought-after species, another large Underwing landed on the same tree. This was a Red Underwing (C.nupta), by far the commonest of the catocalids but the last to put in an appearance in what had been an incredible August. We walked back to the car via the sugared ride and found another Clifden Nonpareil along with a few more Dark Crimson Underwings so all in all an extremely successful evening.
I ventured out one more evening to my Surrey in the autumn, with a Gavin Maclean and Mark Edgeller from Hants and once again we were successful with 2 Clifden Nonpareils and the last Dark Crimson Underwings of the season. Unsurprisingly the Hampshire crew were happy bunnies indeed as they returned home that evening.
So that was that. On reflection, August 2021 will go down as one of my best moth-ing months ever. I managed to lure five species of catocalids (promissa, sponsa, electa, fraxini and nupta) and saw a sixth courtesy of Bob Arnfield (nymphagoga). With the rarity of two of these species, I suspect that this might actually be a unique achievement in British moth-ing! Roll on August 2022!
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