Moths on West Wickham Common in 2013

by Bill Welch.

My moth trapping on West Wickham Common as a volunteer for the City of London Commons is introduced in my article on Moths on West Wickham Common in 2012.

I carried on trapping once a month during 2013. The local Ranger, Luke Barley, put out the trap, as well as storing it when it wasn't in use, and I would come along in the morning and do the fun part, opening the trap and cataloguing and photographing whatever was inside.

Other creatures would also turn up, mostly Arachnids and beetles, but also wasps, and one must be an the alert for hornets, which can be aggressive and painful. Luckily I have seen none on this site.

April 2013

When opening the trap, we also looked all around it, in the grass and particularly on the walls of the Ranger's house. Light reflects off the walls and attracts moths, which seems logical. But also, some will settle just in the edge the area of light. I would not want to miss any of those, or worse, squash them accidentally.

Although some moths can be found at any time of year, a combination of weather and other factors meant that we didn't start until April.

It was cool and moist, and we found two moths, one in the trap and one in the grass nearby. Both were Oak Beauties, Biston strataria, a pretty species that we had not seen in 2012, perhaps because that year, we didn't start trapping until May.

May 2013

I was hoping for more in May, but we didn't even see any of the four species from May 2012. As I pulled the egg cartons from the trap, I only found a single moth. But it was rather a nice one.

The family Notodontidae has produced a slew of interesting moths.

This one, the Lesser Swallow Prominent, Pheosia gnoma, manages to look very smart with its gradations of brown and cream. It has the big ruff and rather spiky appearance typical of the Prominents. Its larvae eat birches, common in the local woods, so food availability is not a problem.

From the front it looks very furry, typical of the family Notodontidae.

June 2013

Suddenly, the weather improved. It had been cold and rainy, like much of the previous year, and now a late warm spring was upon us.

This time I was accompanied by Ishpi Blatchley, and we had a great time. We found representatives of 12 moth families. It was lovely to come across the Figure of Eighty, Tethea ocularis octogesimea, in a distant position on the wall, with its name written clearly on its wings.

The most unusual moths in the trap were two Festoons, Apoda limacodes, whose larvae live on oak. This is noted in our books as Nationally Scarce B; not a real rarity, but "recorded from 31-100 10km squares in Great Britain since 1 January 1980." That is, out of the 2858 such squares in Great Britain that contain land.

Where it does live, it can be found in some numbers. We later found another specimen on a different site about a mile away, so it is probably well established here.

In June there were 92 moths in total, of 40 species. A bit better than May's 1 and 1!

The two photos at the top of this page are also from June.

July 2013

In July, The catch was even better. We saw 228 moths of 77 different species.

The July micromoths were more colourful than the macros. I was pleased to have the excellent Field Guide to the Micromoths of Great Britain and Ireland by Sterling and Parsons, with Richard Lewington's illustrations. Without it, the micros would have been much harder to identify.

Among the colourful micromoths were two different species of bright gold and white striped Argyresthias, A. brockeella and A. goedartella, gleaming at me from the depths of the trap.

There were also two of the brightly coloured pine-tree specialists, Rhyacionia pinicolana and Lozotaeniodes formosana. And a couple of the macros were also dependent on the small and decreasing number of Scots Pines on the common; a tattered Pine Hawkmoth, Hyloicus pinastri, and a Pine Carpet, Thera firmata.

In June we had seen a vividly-coloured Small Elephant Hawkmoth, Deilephila porcellus. This month we had its equally vivid larger cousin, the Elephant Hawkmoth, Deilephila elpenor.

There were three more of the scarce Festoons, and one moth which almost remained a mystery until I discovered that despite looking like one of the Geometridae, it was actually a Noctuid; a Waved Black, Parascotia fuliginaria. Like the Festoon, this one is Nationally Scarce B.

There were seven Buff-tips, Phalera bucephala, an amazingly well disguised moth of which there is a photo in the 2012 article. There were Buff Arches, Habrosyne pyritoides, with wings partly bare of scales; and Peach Blossoms, Thyatira batis, with gentle patches of peach colour.

The oddest-looking macromoth was a single Chinese Character, Cilix glaucata, a bird-dropping imitator which is really good at it.

August 2013

In August, catch numbers were decreasing again, and this time we saw 72 moths of 27 species.

The moths of late summer and autumn are predominantly brown Noctuidae, but there were still a few bright creatures around, and we had three of the black-and-white patterned Black Arches, Lymantria monacha, and a bright yellow Brimstone, Opisthograptis luteolata - both shown in last year's article.

The Lesser Broad-bordered Yellow Underwing shown, Noctua janthe, is typical of this group. This species has greenish-yellow "shoulders" which make it very easy to distinguish from similar relatives, even when not very clearly marked.

There was also an Oak Hooktip, Watsonalla binaria, typical of this oak-rich area.

There were several species of small grass moths that are often seen flying ahead when you walk through the long grass, such as Agriphila species from the sub-family Crambinae, and the Straw Dot, Rivula sericealis, in an unusual habit for one of the Noctuidae.

September 2013

The weather was cooling and there was dew on the grass. In and around the trap were 16 moths of 8 typical autumn species.

These included Large and Lesser Yellow Underwings, Noctua pronuba and Noctua comes; Pale Mottled Willow, Paradrina clavipalpis; Light Emerald, Campaea margaritata; and the micromoths Eudonia pallida and the prolific Light Brown Apple Moth, Epiphyas postvittana.

The Lunar Underwing, Omphaloscelis lunosa, can be marked with varying degrees of emphasis and darkness of shade. The type shown seems to be typical for this area; it's also what I see in my garden trap a mile away.

I photographed that Brindled Green, Dryobotodes eremita, against oak bark, to show how well the brindling breaks up its shape and camouflages it. Its larval food plant is oak, so it is fair to assume that the adult might rest there.

Again, a predominance of brownish Noctuidae.

October 2013

In October, only four moths of two species, all very representative of the season. Two Red-green Carpets, Chloroclysta siterata, and two November Moths, Epirrita dilutata agg.

Only one was actually in the trap. The other three were on the nearby wall.

Three of our Epirrita species can't be distinguished without microscopic examnation of the male genitalia, so they are usually recorded like this, as an aggregate.

This was the last trap of the year. Weather and the lack of early morning light kept the trap indoors until 2014.

Year's End

So, our seven nights of trapping brought in 415 moths of 127 species. That was pretty good compared with 2012, when six nights brought 229 moths of 89 species. It has been a good year everywhere for moths.

This is not a lot compared with some trapping sites, but West Wickham Common is not the best spot for Lepidoptera generally. My butterfly transects don't show any large numbers or unusual species. So I am happy that we are doing well for the site.

The species were split about evenly between the so-called macromoths and micromoths. Those names are pretty arbitrary, but they do in most cases reflect the sizes of the moths concerned. When untrapping, you have to look slowly and carefully to be sure you are not missing some of the tinier species.

There are other ways to catch moths. Light trapping shows a good proportion of available species, but not all of them. I am also quite certain that more frequent trapping would give us, not only more moths, but many more species. I have two reasons for this.

First, that 57 of the 127 species seen this year were represented by single specimens. It was the same in 2012, and only 10 of these were the same species again. It must be pure random luck that brought these in and not singletons of other species. And we missed 37 species that were seen last year, which must surely still be in the area.

Second, that trapping in my tiny garden a mile away, usually three times a week, I saw 197 species, 70 more than at West Wickham Common. Outer suburbia is most unlikely to actually host more species than the common.

Of those we did find, two species were rated Nationally Scarce B: Festoon and Waved Black. I saw no scarce species in my garden, though there is at least one other in the general area (Kent Black Arches, Meganola albula, Nationally Scarce B; trapped on Hayes Common SSSI on 27 July 2013).

A specimen of Crescent Plume, Marasmarcha lunaedactyla, was unexpected, as its larva requires Restharrow, a chalk downland plant. The nearest chalk downland is several miles away, showing that the rather fragile adult must have done some travelling. I found another specimen in my garden. Perhaps they were brought in by an unusual wind.

As with 2012, I checked the food plants of the larvae of all species caught. They were very varied, including broadleaved and evergreen trees, shrubs, herbaceous plants, grasses, lichens and mosses. The varied local environment clearly encourages biodiversity.

Once again, it is worth noting that there was no sign of the Oak Processionary Moth, Thaumetopoea processionea, a notifiable pest known to be established not far away. Good news for the common!

If anyone wants more details of the catches, there is a spreadsheet with the full results here: West Wickham Moths 2013

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The cross-hatched background to some of my photos is measuring paper in neutral grey with squares 5mm across, which gives both the actual and relative size of the moths.