September has been an amazing month for one rare moth in Devon. Catocala fraxini, which has the wonderful english name Clifden Nonpareil (nonpareil meaning unparalleled or beyond compare), is a rare immigrant species, usually only seen once or twice a year in the county. According to the Devon Moth Group database, the best ever year here for Clifden Nonpareil was 2007, when there were three sightings. Last year there was just one and 2015 yielded two.
However, during September 2017, six records (of a total of seven individual moths) have already been reported in Devon. These have occurred throughout the month (from the 4th to the 27th) and right across the south of the county from Axminster in the east to Bere Alston in the Tamar Valley in the west. One lucky recorder, Nick Roach, found two at once, one in his garden moth trap and another on the wall of his house.
This impressive moth, with a wingspan approaching 10 cm and a stunning violet-blue band on the hindwings (giving rise to the alternative vernacular name of Blue Underwing) is currently colonising several areas of southern England and is regularly caught nowadays in parts of Dorset, indicating the presence of resident populations.
With luck, the big increase in sightings in Devon this autumn may also herald the arrival of local breeding colonies of this wonderful insect.
Clifden Nonpareil seen near Culmstock on 26th September 2017 (Nick Roach)
Different moths fly at different times of the year so there is an ever changing line-up of species for moth recorders to enjoy as the weeks go by. While the peak in species richness happens in the first half of the summer, there are plenty of autumn species (and even a few winter specialists) to look forward to in the next few months.
The time of year, therefore, provides an important clue to help with the identification of moths that you might see. While UK field guides to moths give general information about the flight periods of each species, there may be differences between the overall UK situation and the timing in Devon.
Using data from the Devon Moth Group database, Phil Dean has created two really useful resources about the timing (phenology) of moths in the county. One shows the main flight period (in months) for each macro-moth species and the other lists the macro-moth species likely to be on the wing in Devon in each month of the year.
Flight period information about Devon moths can be found here.
Barred Sallow (Iain Leach)
Migrants have dominated the Devon moth news during 2015 and recent months have been no exception. The undoubted highlight of the autumn was Devon’s first ever Tunbridge Wells Gem (Chrysodeixis acuta), shown in the photo below. This is a rare immigrant that had been recorded on only 20 occasions ever in the whole of Britain and Ireland prior to 2015.
This exciting new addition to the Devon moth list was caught by Phil Barden on the coast near Noss Mayo on 7 October 2015.
Tunbridge Wells Gem (Phil Barden)
An ultra-rare immigrant moth, the Accent Gem Ctenoplusia accentifera, has been spotted in Devon. This African species has only been recorded in Britain once before , way back in 1969 in Kent, so the discovery is very significant.
Devon Moth Group member, Dave Wall, found the moth in his garden moth trap in Exmouth on 29 October, during a major period of moth immigration to the southern coast of Britain that accompanied very mild weather and southerly winds. In fact, in the same moth trap, Dave also caught two Palpita vitrealis and three Vestal Rhodometra sacraria, quite exciting immigrant moths themselves.
This is the second extremely rare migrant moth caught in Devon in recent months. Back in July, Group members found a Ringed Border Stegania cararia, which was also a species never seen before in Devon and was only the third known British record.
Autumn can be a time of great excitement for Devon’s moth recorders as moth migrate northwards from the continent and arrive on our shores. In some years, little arrives but in others (most recently 2013 and 2011) an amazing variety of common, scarce and downright rare immigrant moths come in, to the delight of wildlife enthusiasts.
So far this year, most of the migrant moth excitement has been among moth recorders on the east coast of Britain. However, the South West hasn’t missed out entirely. Perhaps the pick of the crop so far have been two records of the large and dramatic Clifden Nonpareil (Catocala fraxini) – a moth that would feature on most moth recorders’ bucket lists. The first was caught by visiting moth expert Dave Grundy at Prawle Point on 27 August, while the second came to Mike Lockyear’s moth trap in Crediton on 17 September. Both are shown below. The species has also been reported from other locations around the English coast from Dorset to Northumberland in the past few weeks.
A range of other immigrants have been seen in Devon in recent weeks including the massive Convolvulous Hawk-moth, Delicate, Vestal, Scarce Bordered Straw and Ostrinia nubilalis.
With mild conditions forecast for the week ahead, it would be well worth looking out for rare visitors to our county.
Clifden Nonpareil (Dave Grundy)
Clifden Nonpareil (Mike Lockyear)
Autumn is typically an exciting time of the year for those interested in moths. Although the great diversity of British moths that are around during the warm summer months is starting to fade, it is the peak time of year for moth immigration.
In good autumns, such as in 2011, huge numbers of moths can arrive in Britain from southern Europe or even North Africa, borne in on warm southerly winds. While some of these are common and familiar migrants such as the Silver Y, Dark Swordgrass and Humming-bird Hawk-moth, other much rarer and more exotic-looking species can arrive, such as the sinister Death’s Head Hawk-moth, the stunning Crimson Speckled, Dewick’s Plusia and Purple Marbled.
The number of exicitng immigrant moths has started to rise in Devon and neighbouring counties in recent weeks with, for example, sightings of the very rare Rosy Underwing in Dorset and Cornwall. This species had only been recorded 10 times ever in Britain prior to this year, but there have already been three sightings in recent weeks (two in south Dorset and one on the Lizard, Cornwall).
I’ve not been lucky enough to see anything so rare (although with moth recording one always lives in hope) but have seen several immigrant Vestal moths in my garden in the last two weeks (one shown below). It’s well worth putting your moth trap out at night between the showers and also keeping your eyes peeled during the day as species such as Convolvulus Hawk-moth and Crimson Speckled are often spotted by day.
Vestal (Richard Fox)
The Swallows may have flown and butterflies and dragonflies are fluttering to the end of another year’s activity, but autumn is an exciting time for moths. Many of our most beautiful and intricately marked species are on the wing at this time of year.
Some autumn moths are beautifully camouflaged to match the changing leaves. The yellows, oranges and pinks of species such as the Centre-barred Sallow, Pink-barred Sallow (below), Barred Sallow and Feathered Thorn, enable these moths to blend in perfectly among the autumn leaves.
Pink-barred Sallow (David Green)
The Angle Shades moth takes the subterfuge one step further, being not only coloured like autumn leaves but also folding its wings in such a way as to resemble a curled dead leaf. This moth is often encountered during the day as it tends to rest in exposed positions, such as on walls and fences.
Perhaps most glorious of all, the wonderfully-named Merveille du Jour, blends in perfectly among lichen-encrusted branches and rocks. It is on the wing now and regularly seen in moth traps in woodlands and gardens across Devon. Well worth keeping the moth trap going during warmer autumn evenings.
Merveille du Jour (Patrick Clement)