31-Jul Gossamer & Gold: London’s Overlooked Day-Flying Moths

Disturbing vegetation in gardens may put up a colourful black, white and yellow Magpie moth. The Shaded brood-bar is one of the moths most commonly seen during the day. It is a tawny brown with broad central, almost chocolate, bands across its wings. The turmeric-coloured Yellow shell is rarely seen, unless the vegetation is disturbed. If a small green moth is seen in woodland it may well be a Green carpet. If the wood is one that was filled with anemones earlier in the year then it might be worth looking for the Twin-spot carpet. Similarly, a purple moth seen during the day on heathland could well be the Small purple-barred.

There are few noctuids which are day-flyers but the Beautiful yellow underwing is one of the most impressive. It is more reddish-brown than other noctuids and has possibly the best colour patterns and marbling of the group. In London it is very local in its distribution, but is worth seeking out on Fairmile Common or perhaps Wimbledon Common. The True lover’s knot is a similar impressive noctuid which is also common, but only south of the Thames. A lot of our other day-flying moths are now either rare or extinct. These include foresters, several burnets, the Satyr pug, Drab looper, Marsh pug, Festoon and the Four-spotted.

The custard yellow Dew moth may still be worth looking for on Box Hill as well as the similarly yellow Clouded buff in the Banstead area. The latter has a pink fringe around the edge of its wings. The most dramatic of all the day-flyers has to be the Hummingbird hawkmoth which always gets remarked upon as it is seen hurtling through gardens.

The moths most often seen are the typical dull coloured noctuids or owlets which are attracted to our windows and outside lights at night. The name owlet comes from the fact that they nearly all just fly at night. The Double square-spot is one of the most common and widespread and easy to identify.

It has small, squarish black spots on its brown wings. There is also little excuse for missing Dark arches, which is held to be the most common moth in London. Like so many of our moths, it is variable in colour, in this case varying from brown to grey with a melanistic form once again seeming to prefer the East End. A close second for the most common moth is the Large yellow underwing. It betrays its presence when it flashes its rather more orange than yellow hindwings when it is disturbed. Other very common, typically coloured noctuids include the Common, Lesser rustic and Smokey wainscot. The Uncertain is also common, but as its name suggests, difficult to identify although it has got an unusual bulbous end to its abdomen.

The Old Lady is one moth once seen that is rarely forgotten. Although only grey-brown, its sheer size and broad, curved wings at rest always mark it out. It derives its name from the dolman cape worn by old ladies in the past. Although not particularly common it does have the habit of entering houses and hiding in curtains, which is often where we first see it. Oddly, unlike most moths, it seems to prefer central areas where it also seems to be attracted to garden sheds and even London Underground tunnels. Noctuids are not generally known for their beauty, but the True lover’s knot and the Straw dot certainly deserve a second look. The True lover’s knot is only likely to be seen near areas of heath. Although small, it is covered in fine, black, white and reddish streaks and circles with dotted edges to its wings. Sometimes it shows more pinks and purples. The Straw dot has straw-coloured wings with distinct brown dots, which show up more purple and black when you look at them more closely. It is largely confined to marshy areas and wet woodlands.

Footmen are always easy moths to recognise due to their habit of pressing their long, narrow brown wings so close to their body they resemble the buttoned-up appearance of a footman in livery. As a group, some are unusual, feeding on the lichens and green algae that cover tree boles. The Common and Rosy footmen that continue to fly from last month are now joined by the Dingy, Scarce and Four-dotted. There may even be faint possibilities of the Red-necked and Four-spotted footmen.

Yet another attractive group of medium-sized brown moths with interesting patterns and fine metallic markings are the plusias. To aid identification, they have a prominent tuft of scales on their thorax which can look almost like a small hump. The ubiquitous Silver Y is one that is very well known, but other common species include the Beautiful, Plain golden Y, Burnished brass, Golden plusia and the Spectacle.

In many ways they are all similar to the Silver Y, but with different colours and metallic sheens. The Golden Y’s have similar white Y markings on their wings, but are more golden brown in colour. The Burnished brass is more of a brass yellow and the Golden plusia sometimes has markings that, with a little poetic licence, could be described as golden. The Burnished brass has a fondness for nettles and so can be found quite centrally, whereas the Golden plusia prefers delphiniums and monkshood and consequently tends to be found in suburban gardens. Lastly, the Spectacle gets its name from its so-called white rimmed spectacles which can only possibly be seen if the moth is closely examined head on.

As already mentioned there are many micromoths. Even though there are over a thousand in Britain most go totally unnoticed, usually due to their small size and often dull colours. They can be as small as 1½ mm. in length and have larvae so small they can live between the top and bottom of a leaf blade creating the blotches and mines we see on many leaves at this time of year. However, among them there are a small number of more colourful species that often get seen this month.

Some we notice due to their tendency to swarm e.g. the longhorns with their long waving antennae, the green oak tortrix moth Tortrix viridana which is easily disturbed in numbers from oak branches and grass moths which we disturb when walking through uncut grass where they rest usually head down on the grass stalks. They are generally dull in colour and fly short distances before settling down again in the grass. The Chestnut miner moth can also sometimes be seen in number floating around the trunks of Horse Chestnut trees.

Typical features of micromoths that might help you identify them generally are their small size, dull colours, narrow forewings and weak slow flight. Many have small “snouts”, are mostly nocturnal and often attracted to lights. As their diet consists of all manner of vegetable matter they are found in many different habitats. Several have larvae that are even found in bees nests and have names to match e.g. the Bee, Honey and Honeycomb moth. The familiar Common Clothes moth Tineola bisselliella is quite typical in many ways. It is dull coloured, small, runs rather than flies when disturbed and then flies badly when it does. It may well be seeking out old woollens on which to lay its eggs this month.

However, there are some colourful species worth looking out for. The Small Magpie Anania hortulata is very similar to its colourful macromoth cousin the Magpie but only 1½ cms. In length. The Mother of Pearl moth Pleuroptya ruralis has an attractive pearly sheen with rainbow tints and the Common Purple and Gold Pyrausta purpularis has the colours described and just looks like a tiny butterfly. Others such as the plume moths are more easily recognised due to their feathery wings held out at right angles giving them a slightly ghostly appearance. A more unusual micromoth is the Small China-mark moth. This has a larva which makes a case around itself with fragments of our smallest wild flower, duckweed. The adult gets its name from its wing pattern which is supposedly similar to a potter’s mark.