What are moths? What’s the difference between a moth and a butterfly? What is mimicry? What do moths eat? Which species live in the UK? And why are moths important?
Find out the answer to all of these questions and more with our guide to British moths.
Scarlet tiger moth on Foxglove ©Getty
What are moths?
The most dramatic moths in Britain are the hawk-moths. Large and fabulously patterned, their heavy bodies make them slow to take off and they will sit on your hand looking wonderfully glamorous. The elephant hawk-moth is a vibrant combination of lime green and sugar pink. Poplar hawk-moths have sculpted blush-grey wings; displaying red flashes from marks on their underwings if they feel threatened. With their size and colour, these are good species to show children the wonder of moths.
To try and understand moths a bit better, we asked gardener and naturalist Susie White a few questions…
What is the difference between a butterfly and a moth?
Butterflies and moths are closely related and some moths are as large and colourful as butterflies, making it difficult to tell them apart.
A quick way to tell the difference is to look at their antennae: butterflies have clubbed antennae (bulbous at the tips) whereas moths, with the exception of the burnets, do not.
Moths are also far more numerous than butterflies; compare the 59 species of butterflies breeding in Britain with some 900 species of large moths (known as macro-moths) and a further 1,550 or so species of micro-moths.
Speckled yellow Pseudopanthera macularia ©Getty
What do moths eat?
Some moths fly by day, some by night, and my garden is filled with plants to attract them. Single flowers are chosen for their easily accessed nectar, giving adult moths energy for flying and aiming to provide a year-round food supply. Some moths even fly in winter, with ivy flowers providing a late-season feast. My garden is at the meeting of several different habitats – woodland, fields and river – so it’s especially rich in insect life.
Moth caterpillars feed on the leaves and roots of native plants and grasses, so I leave meadow fringes around the garden walls. I grow foxglove, primrose, mullein and thyme in the borders, or cultivated varieties that are related to native species: verbascum, purple plantain, honeysuckle and flag iris. Native trees are especially important and the caterpillars that eat their leaves provide food for birds. Birds feed their chicks with winter moth caterpillars collected from the tree canopy; a single brood of blue tits can eat up to 10,000, their breeding timed to coincide with the emerging larvae.
Yellow-and-black striped cinnabar moth caterpillars Tyria jacobaeae ©Alamy
Moths and mimicry
Moths often use mimicry to protect themselves. Red sword-grass looks like a sliver of wood and has a head like a shaven pencil, only recognisable as an insect when it splays its legs to walk on my hand. Chinese character is a white moth with brown blotches that looks just like a bird dropping. The beautiful buff-tip mimics a broken-off birch twig.
Master of mimicry: a twig-impersonating buff-tip moth ©Alamy
Where do moths get their names?
Their imaginative names are a joy. Thought up by Victorian naturalists, these were often drawn from life in the ‘big house’; there are ermines, satins, brocades, footmen and wainscots. Some names come from their markings: Hebrew character, garden tiger, feathered gothic, speckled yellow, blood-vein and leopard moth. Angle shades is a perfection of symmetry and herald wears the rich velvet of a medieval costume.
Why are moths important?
As well as being pollinators, moths play a vital in the food chain. They’re relied on by birds, spiders, bats, amphibians and hedgehogs. Their declining numbers – down by 40% in the south of the UK – is alarming and is having an impact on other species.
Greater horseshoe bat catching a moth ©Alamy
10 amazing garden moths
Get to know some of the fascinating moths you could find in your own back garden
Scarlet Tiger Callimorpha dominula
The day-flying scarlet tiger flashes its dramatic underwings as a warning to predators that it’s poisonous. The caterpillars, known as ‘woolly bears’, have irritant hairs and are only eaten by cuckoos.
Poplar Hawk-moth Laothoe populi
Resting with its hind wings projected forwards, the poplar hawk-moth has a sculptural outline. Hold one on your palm and it takes several minutes of vibrating its wings before it can fly.
Large Emerald Geometra papilionaria
Every bit as colourful and large as a butterfly, this beautiful jade-green moth has delicately scalloped wings. It rests like a butterfly, too, with its wings spread out.
Merveille du Jour Griposia aprilina
Flying in autumn, the fabulous merveille du jour really lives up to its name. Wings are frosted green with sharply patterned black-and-white markings, camouflaged when seen against lichen.
Silver Y Autographa gamma
An immigrant species, silver Ys are seen as a blur of grey wings in daytime as they fly rapidly between flowers. When they settle, you can clearly see a white Y shape on their forewings.
Angle Shades Phlogophora meticulosa
Camouflaged to look like a crumpled dead leaf, angle shades has pinkish brown markings on creased and folded wings. Often seen in gardens by day, it’s the moth that first got me hooked.
Buff-tip Phalera bucephala
The markings of this remarkable moth mimic a broken birch twig. Mottled silver-grey wings resemble birch bark while dark edging lines emphasise buff patches, the colour of pale wood.
Emperor Moth Saturnia pavonia
Emperor moths have four large eye spots to deter birds. Males can detect the scent of females from several kilometres away; you can buy pheromone lures to attract this spectacular species.
December Moth Peocilocampa populi
Flying in the middle of winter, the charcoal-coloured December moth looks like it’s wearing a furry hat and warm clothing. Males, though smaller than the females, have impressive feathered antennae.
Buff Arches Habrosyne pyritoides
This extraordinary moth sports a combination of smooth grey wings overlaid with orange-brown wavy markings that distort the sense of space like a piece of 1960s psychedelia.
Garden plants for moths
Nicotine plant Nicotiana alata
Not all moths drink nectar, but night-scented flowers will attract those that do. Grow species with short tubes, such as Nicotiana alata rather than N. sylvestris.
Sweet rocket Hesperis matronalis
With a sweet yet spicy scent, this is a mid-height cottage garden favourite that self-seeds easily. Flowers vary between white, mauve and purple.
Catmint Nepeta ‘Six Hills Giant’
This large catmint flowers from July to October and is a magnet for bees, hoverflies and day-flying moths, such as silver Y.
White rosebay willowherb Chamaenerion angustifolium ‘Album’
Though it is invasive, I grow white rosemary willowherb as a food plant for elephant hawk-moth caterpillars. Stately and serene, it has waving tall white plumes.
BuddleJa Buddleja davidii
Also called the butterfly bush, buddleja produces an abundance of nectar-rich flowers that butterflies and moths find irresistible.
Wallflower Erysimum cultivars
Richly scented spring bedding, wallflowers provide early season nectar along with bluebells. Perennial wallflower ‘Bowles’ Mauve’ attracts hummingbird hawk-moths.
Moths with long probosces can feed on nectar deep in the tubular flowers of honeysuckle. Leaves are food for caterpillars of the early grey and twenty-plume moth.
Knapweed Centaurea nigra
Adult moths take nectar from both native and non-native plants but caterpillars need natives. Meadow flower knapweed is the larval food-plant of several species.
Marjoram Origanum vulgare
Purple and scented, marjoram flowers provide nectar for many insects, including moths. It’s the larval food-plant of the beautiful metallic-sheened burnished brass moth.
How to trap moths
Trapping moths does not hurt them and I let them go the following night. It’s similar to bird surveying with a mist net: catch without harming, identify and release. There are several types of trap but the one I prefer to use is a Robinson. Moths are drawn by the light of a bright bulb and funnelled down into the large black tub below. I line this with egg cartons so there are plenty of places to hide, setting the trap just before dusk and turning the light off at dawn. It’s a race to get there before the robin who might take advantage of an easy meal.
The Robinson Moth Trap
Discover night-flying moths by simply leaving the outside light on or by making a sugary bait. There’s a guide to moth traps in the Moth Recorders Handbook, downloadable from mothscount.org, and Paul J Palmer has written a book How to Build Your Own Moth Trap (CreateSpace, £6.80). Anglian Lepidopteris Supplies (angleps.com) sells a range of equipment for moth trapping; traps also available from Watkins & Doncaster (watdon.co.uk). The Field Guide to the Moths of Great Britain and Ireland by Waring, Townsend and Lewington (Bloomsbury, £40) shows moths in resting positions. For supportive sharing, go to Facebook @GardenMothScheme, and there are some good county websites, such as northumberlandmoths.org.uk.
Words: Susie White
Illustrations: Chris Shields