Now in early October, numbers of butterflies are drying up to a mere dribble – in my garden, the last of the Large Whites, Small Whites, Red Admirals and Speckled Woods are weakly fluttering.
However, if you run a moth trap, you find that your garden is still very much alive with their more elusive cousins.
So, last Saturday, I put out my trap with what is called an actinic bulb, which glows with a rather bluish ethereal light but isn’t so bright as to trouble the neighbours. Should they look out, they might merely think that a little alien spaceship has landed.
The trap contents by the next morning were pretty impressive. They included several specialities of the season, such as this Dusky Thorn, which like most of the thorn moths holds its wings aloft, half open.
There were also these, which I love for their subtle colour variations – the Lunar Underwing.
But there were three moth species that really stood out for me.
The first was this moth, Blair’s Mocha (not named after Tony, you’ll be glad to know, but sadly not named after Lionel either). It is one of those moths that holds its wings out flat as a pancake. It has little hooks at the wingtips, and a little black ring around a pale spot in the middle of all four upperwings.
So why my interest? Well, this European moth was only first recorded in the UK in 1946. It remained a rare autumn migrant until the 21st century, when it appears to have colonised my county of West Sussex. Its caterpillars feed on Holm Oak, of which I have three mature trees in my garden, so I could well be hosting a breeding population of this rare moth.
The next was this, Clancy’s Rustic. Ok, so it is not going to win any awards in the ‘pretty’ or ‘colourful’ categories, but it is easy to identify with this pale, pasty background colour and then the small shape three quarters of the way down the upperwing – a feature called the kidney mark that you find on many moths – standing out in a much deeper brown colour.
It is an even more recent arrival, first seen in the UK in 2002 as a natural vagrant from continental Europe. Here we are only 19 years later, and I had three in just one night in my trap. Other moth trappers in southern England are getting double figure counts easily. It is a moth on the move.
But the commonest moth in my trap by far – with 94 individuals – was this.
Although sometimes it looks like this.
It is the Box Tree Moth.
Forget Box Blight, the fungal disease that is afflicting Box bushes. The caterpillars of this Introduced Non-native moth are running absolute riot on the common hedging plant. This east Asian species was only first recorded in the UK in 2007, but by 2018 had reached Scotland.
So, in just one night’s moth trap, we have a vivid picture of some moths colonising the UK naturally as climate change pushes them north, and others that we have accidentally introduced going ‘boom’.
What next? We wait with bated breath! But for proof that the world is already changing due to mankind’s influence, and at considerable speed, just pop out a moth trap and see for yourselves!
If you want to drop by my RSPB wildlife gardening blog, it is updated every Friday, and I'd love to see you there - www.rspb.org.uk/community/blogs/hfw