Clifden Nonpareil at Parc Slip!

September was a marvellous Moth month! 🙂

Look at the beautiful blue underwing! Clifden Nonpareil by Vaughn Matthews

Look at the beautiful blue underwing! Clifden Nonpareil by Vaughn Matthews

It’s exciting to know that even after nearly 9 years of weekly moth trapping at Parc Slip you can still get new species turning up.

On the morning of the 16th of September the first moth I saw resting on the wall near the trap was a large and, at least initially, fairly nondescript grey moth. However its sheer size meant I knew it was something that I’d not seen before. When I went to collect the moth in a pot for safekeeping it moved slightly and flashed the beautiful blue underwings that unmistakably identified it as the fantastically-named Clifden Nonpareil (Catocala fraxini).

Their common name originates from where it was first discovered (at least in the UK) which was at Clivedon House near Maidenhead. The ‘nonpareil’ part means without compare which is apt when you see it up close! They are also sometimes known by the rather more prosaic name Blue Underwing. Their scientific name ‘fraxini’ relates to Ash (Fraxinus excelsior) as that’s what it was supposedly originally found resting on. The species has no actual connection with Ash however as its caterpillars feed on the leaves of Aspen trees.

The moth used to be resident in the UK, mainly in Kent and Norfolk, but became extinct in the 1960s. It has been a fairly regular immigrant to the UK from Eastern Europe in most years though usually they are very scarce. Occasionally they are recorded in relatively large numbers if the weather conditions are right and their arrival usually coincides with that of other rare immigrant insects and birds. Since the turn of the century the number of immigrant Clifden Nonpareils has been increasing and it has now recolonized some of the southern counties of the UK as a breeding species.

It’s difficult to say whether the Clifden at Parc Slip originated in the UK or was a migrant from Europe but there were a handful of other records in South Wales around the same time which suggests that they were migrants. Either way it was the highlight of my moth trapping year and a great addition to Parc Slip’s species list!

Vaughn Mathews, Wildlife Trust Officer