Rare moth spotted at Pitsford Water

Clifden nonpareil moth at Pitsford Water by Dave Jackson

A rare blue underwing makes an appearance.

Being a moth’er, friends always come up to me with wonderful pictures of moths or caterpillars they have found (or any invertebrates for that matter). Last year I got very excited when our Volunteer Officer had the same experience from his friend who had shown him what he assumed was an ordinary, if somewhat very large moth that turned up in his bathroom. It was however a Clifden nonpareil, also known as the Blue Underwing. 

This absolutely stunning moth is high on any moth’ers wish list because of its beauty and also because it is very rare. We were obviously very excited to have a new record for the county, only to find out that the moth was actually recorded just over the border in Oxfordshire. Technicalities meant it was not a county record, but a very exciting record none-the-less.

I am fortunate enough to check two moths traps almost daily as part of my role at Pitsford Water nature reserve. The other morning I was extremely excited when, what I initially assumed was a Red Underwing, (the common relative of the Blue Underwing), jumped onto my hand, and then flashed her beautiful blue hindwings at me! 

Clifden nonpareil - blue underwing - moth at Pitsford Water

Clifden nonpareil - blue underwing - moth in September 2019 at Pitsford Water by Dave Jackson

This wonderful blue moth was much more obliging than her red counterparts, who tend to fly off when you go anywhere near them. She let me pop her in a large pot to get some photographs of her. Word quickly spread and quite a lot of people popped by to photograph her and observe her beauty.

Photographers interested in the blue underwing moth at Pitsford Water nature reserve

Photographers interested in the blue underwing moth at Pitsford Water nature reserve - by Mischa Cross

It is quite a common strategy for moths to have cryptic grey or brown markings on the forewings to blend into their surroundings, but some also have an added defence of bright underwings to shock any predators that do discover them. Blue is an unusual colour for UK moth species, most underwing species use the typical warning colours of yellow or red, or even eye markings as with the Eyed Hawkmoth.

This species was first recorded in Northamptonshire (VC32) sometime around 1900. The date and location of this record is not known but it was published in 1907. Just pipping this Pitsford moth to the post of being the first Blue Underwing since the 1900s, one was taken in a garden light trap on 25th Aug 2019 in Old Stratford, so the Pitsford one is the third known of all time in the area.

The Blue Underwing has had a very up and down time in the UK. It used to be a resident, only in Kent and the Norfolk Broads until around the 1930s. It has since recolonised the south coast, particularly the Dorset area from around 2007 and has in recent years been popping up in counties further North. The county Recorder for Northamptonshire took three from Chippenham Fen just last week. It is very difficult to know for sure of course if these records are from local breeding, migration from the Continent or dispersal from more distant, but UK resident colonies. Time will tell if this beauty is a more regular visitor to our light traps.