Late Summer Moths in Kelsey Park

by Bill Welch

Moth trapping in Kelsey Park, Beckenham in August 2013. Photo by Liz Anderson.

During the bat walk that took place in Kelsey Park, Beckenham, on 30 August 2013, a lone figure was caring tenderly for a strangely lit white box not far from the information centre. It was me, and the box was my moth trap.

I was interested to find out what moths lived in the Park. Apart from their value as themselves, a good moth population would provide food for the larger bats. The small bats would probably feed mostly on midges.

Yellow Shell, Camptogramma bilineata bilineata. Photo by Bill Welch.

As soon as I turned on the trap's light at sunset, I saw a column of midges form above it, and from then until I closed down, midges arrived at the trap in their dozens. Some were small, some large. Luckily they mostly seemed to be non-biters, but they buzzed around my face and got into my mouth and eyes in a very annoying way. I was hoping for a squadron of Pipistrelle bats to come and hoover them up, but I only saw an occasional bat in my corner.

Broad-bordered Yellow Underwing, Noctua fimbriata. Female. Photo by Bill Welch.

There was not much moth activity for the first hour. One large creature, an Old Lady moth, Mormo maura, investigated the light and then moved on. A few small moths dropped in; grass moths and fruit tree moths. Then, about ten minutes before the bat group came to see what I was doing, some more interesting arrivals began.

There are about 2,400 species of moth in Great Britain, as compared to about 60 species of butterfly. They are very similar to each other, and are closely related. We are often asked what the difference is, and there is no simple answer. In fact, some would say that butterflies are just a day-flying kind of moth. But in general, you can say that butterflies fly by day and have club-shaped antennae. Most moths fly by night - though some fly by day - and most have either feathery or simple pointed antennae.

Common Plume, Emmelina monodactyla.
Photo by Bill Welch.

Being colourful is not a useful guide. Many moths have quite a plain brown appearance, but many more are brightly coloured, and even those with brown forewings often have vivid red or yellow hind wings that show up beautifully in flight. We saw some of all three of these variations in the trap.

Two brightly patterned yellow moths appeared early on - a Brimstone Moth, Opisthograptis luteolata, and a Yellow Shell, Camptogramma bilineata bilineata. Many moths are very seasonal, but these two can be seen for most of the summer. We were also visited by a Forest Bug, Pentatoma rufipes, a metallic bronze shield bug with a yellow and black chequered border. This is one of the true bugs, and is a common sight in the local oak woods. By now, a group of children had arrived at the trap, and the Forest Bug was quite a hit.

Forest Bug, Pentatoma rufipes. Photo by Bill Welch.

And now more moths came flying in. We saw some of the yellow underwing group, and also a couple of plume moths. In flight, some moths wander through the air like drifting thistle seeds, others blunder around noisily like out-of-control dive bombers. Plume moths are the microlights of the moth world, moving slowly and daintily. When they land, instead of cocking their wings like butterflies or laying them along their back like most moths, they roll them up like umbrellas, and end up in a T-shape with the rolled wings out at each side of a stick-like body. On this night we saw a Common Plume, Emmelina monodactyla, and a slightly more showy Beautiful Plume, Amblyptilia acanthadactyla.

Shuttle-shaped Dart, Agrotis puta puta.
Photo by Bill Welch.

The largest moth of the night was a dark brown Old Lady, perhaps the same one I had spotted earlier. I was pleased to see it back, especially when there was a group there to appreciate it. This moth has a 60mm wingspan, so is hard to miss. They are doing quite well this year. I have seen a couple stranded on pavements in the mornings. Our visitor entered the trap this time, and stayed long enough to be seen and appreciated before leaving once again.

No-one really knows why moths are attracted to the light. Some moths are not, and plenty of other insects are. Light traps often bring in wasps, so a bit of care is needed. We also see caddis flies, bugs and beetles, as well as the midges that Kelsey Park's lakes were giving us in such numbers. The Park clearly has a healthy range of mini-wildlife. We saw a total of 27 moths of 17 different species.

The light trap we used does no damage, and all the creatures flew away unharmed when the trap was dismantled.