As spring blossoms, so too do London’s moths, emerging in a stunning array of shapes, colours, and patterns. From the regal Emperor moth to the delicate Green Longhorn, these nocturnal wonders are taking flight in gardens, woodlands, and even city parks. Did you know some moths mimic twigs, while others are drawn irresistibly to light? Join us on 13 April as we delve into the hidden world of moths, exploring their fascinating behaviours, unique adaptations, and the surprising role they play in London’s ecosystems. Don’t miss this chance to discover the beauty of the night!
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Moths
Most of the moths mentioned so far this year are still flying in April, especially numbers of Early Thorn, Engrailed and some Quakers. Along with the general resurgence of insect life, several new moths are now emerging, particularly at the end of the month. Of the new ones, the most commonly encountered are likely to include the Purple Thorn, Double-Striped Pug, Lunar Marbled, Narrow-winged Pug and Brindled Pug. Pugs are mainly small, brown and grey moths which rest with the front edge of their forewings in a straight line rather like a bi-plane; they also tend to have noticeably curled abdomens. The Purple Thorn is a rich purple-brown and raises its wings with their jagged edges when at rest. Their caterpillars feed on sycamores remaining motionless and imitating twigs when disturbed. The Double-striped Pug is a handsome brown and is often found trapped in light fittings, to which it seems fatally attracted. The Narrow-winged Pug is associated with heather, on which it feeds, but with no moors in London it seems to be content with ornamental heathers in gardens. The Brindled Pug is likely to be first encountered as it is the earliest to emerge and the Lunar Marbled is widespread everywhere, except in central London, which is such a desert for moths generally.
Moths which are locally abundant this month include the Water Carpet, Chocolate Tip, Frosted Green, Small Engrailed, Streamer and Emperor. The Chocolate Tip, Streamer and Emperor are attractive moths and well worth searching for. At rest, the Chocolate Tip as its name suggests has handsome reddish chocolate coloured tips to its wings. It is usually found in willow carrs where it feeds on sallow and aspen, but only in south London. The Streamer got its name for the black wavy strip which can be seen across its wings when it rests. These moths are usually grey but some are violet when they first emerge.
The Emperor moth needs little introduction, being one of the largest and most handsome of all our British moths. It has large ‘eyes’ on its wings and luckily flies during the day, flying so fast it is often mistaken for a butterfly. The male is attracted to the female by her pheromones. He is not usually attracted to lights and is more often seen on heaths, although he can tolerate other habitats. The Water Carpet is a deep brown with distinctive jagged white markings and prefers dense woodland. The Frosted Green is dark green with a black and white tuft on its thorax. The Small Engrailed with its wavy cross-lines is rather larger than most moths encountered this month and comes to lights in numbers.
Species that may emerge late in the month are the Mullein, Chamomile Shark, Waved Umber, Early Tooth-striped, Garden Carpet, Great Prominent and the already mentioned Narrow-winged Pug although with changing weather patterns, many more moths may start emerging earlier. The Mullein is more famous for its caterpillar, which is a dramatic white and yellow with black spots. They are found, as you might expect, on mulleins Verbascum spp., but also on Buddhlia and figworts. The Chamomile Shark is so called because of its pointed collar, which curiously reminded its first author of a shark’s dorsal fin. It also has a beautiful caterpillar with green stripes and pink blotches. The Waved Umber has attractively-designed camouflage markings and the Green Carpet is probably one of the most common of all moths in the capital. It is especially common in gardens, but varies in its appearance, forty per cent of individuals being darker melanistic forms.
Other April rarities include the Mottled Grey, Marbled Pug, Oak Tree Pug, Great Prominent and Northern Drab. Probably now lost, but present in the past, are the Gem, Barred Tooth-striped and Barred Umber. The Northern Drab may still exist on Ashtead Common but seems to be lost from its former haunt of Mitcham Common. Ashstead Common is still a good place to look for rare moths, and the attractively-named Blossom Underwing may still be there. The Gem, as its name suggests, was a very handsome moth, the female being a rosewood colour with white dots bordering both of her wings. The Great Prominent is another moth with a striking caterpillar, this one with prominent green stripes. It does not seem to like the activities of man and may be just hanging on in woods at the extreme south western tip of London.
Lastly, there are over one thousand different micro-moths in Britain, many of which inhabit London. They are usually small, plain-coloured moths which are enormously difficult to identify. There is, however, one species that stands out this month. This is the Green Longhorn Adela reaumurella. It is a small, green iridescent moth which is remarkable for the length of its antennae. Compared with its body length, the antennae are the second longest of all our moths. Males are now swarming on the leaves of bushes, all waving their absurdly long antennae at each other.
