British caterpillars: how to identify 10 common species
We all know Britain is home to dozens of gorgeous butterflies and moths. They grace us with their presence each summer and dazzle us with their bright colours and unique patterns. But how much do we know about their caterpillars? Find out how to identify our top 10 British caterpillars, what they eat and when to see them.
Comma butterfly (Polygonia c-album)
Appearance: Like the adult comma butterfly, which resembles a tattered leaf with its scalloped edges and rust-coloured hue, the comma caterpillar is also a master of disguise. It actually looks more like a bird dropping - with rust orange/brown markings and a bright white ‘saddle’ mark. This is so it can hide itself from potential predators when sitting on top of leaves and nettles.
When to see: There are two generations a year, usually around April-May and again in September.
Where to see: They live in open woodland and woodland edges.
Credit: fabioski / chillingworths / iStock.com
Large white butterfly (Pieris brassicae)
Appearance: The large white caterpillar is pale green-yellow with striking black spots and visible hairs on its body. Its bold appearance is a warning to predators of its unpleasant taste. This is due to the poisonous mustard gas its body accumulates.
Diet: Known as both the 'large' and the 'cabbage' white due to its diet of cabbage, this caterpillar is a famous pest, particularly for allotment owners! It is well-known for chomping on cabbage, starting from the outside and leaving only the bare bones of the vegetable behind.
When to see: They can be seen anytime from March to October, but are most active during the warmer months.
Where to see: This widespread species is found across the UK, usually anywhere near cabbages or lettuces!
Credit: Mezmic / iStock.com/ Frank Cornelissen / iStock.com
Cinnabar moth (Tyria jacobaeae)
Appearance: The cinnabar moth caterpillar is hard to miss. It looks as though it’s wearing a rugby shirt due to its distinctive black and orange/yellow stripes. Like many other caterpillars, its stripes are a warning to birds and other predators of its unpleasant taste.
Diet: This caterpillar feeds on a diet of common ragwort. However, it has been known to eat other caterpillars if very hungry!
When to see: It is active from July to September.
Where to see: Usually in open grasslands, woodland rides and heathland.
Credit: chris2766 / Sander Meertins / iStock.com
Peacock butterfly (Anglais io)
Appearance: In contrast with the brightly-coloured adult peacock butterfly, its caterpillar is actually a velvety jet-black peppered with small white spots. It has short spines, which help to protect it from predators. Peacock caterpillars also ward off predators by coming together and jerking their bodies in unison. This gives the illusion they are a much bigger animal. They will also curl up in a ball and drop to the floor or regurgitate a green substance to keep predators away.
Diet: Stinging nettles are their main food source.
When to see: May to June.
Where to see: They can usually be seen from May to June and are widespread in England and Wales.
Credit: tbuprint01 / iStock.com / Amy Lewis / WTML
Sycamore moth (Acronicta aceris)
Appearance: The sycamore moth caterpillar is one of the hairiest and brightest caterpillars in the UK. With yellow and orange hairs and a strip of black-edged white spots along the centre of its back, this is a striking caterpillar to behold. It's a world away from its plain, adult form.
Diet: It is named after its diet of sycamore, field maple and horse chestnut.
When to see: This species can be seen in caterpillar form from June to August.
Where to see: It is found in the South East of England, usually in woodland, gardens, parkland and scrub.
Credit: Nearby/Alamy Stock Photo & Nature Photographers Ltd/Alamy Stock Photo
Speckled wood butterfly (Pararge aegeria)
Appearance: Bright green with dark green and yellow stripes.
Diet: It feeds on a variety of grasses, including cock’s-foot, Yorkshire fog, common couch and false brome.
When to see: They are seen all year round, except for April.
Where to see: As the name suggests, speckled wood caterpillars are usually found on blades of grass in open woodland, woodland edges and rides, hedgerows and scrub.
Credit: rank Hecker / Alamy Stock Photo & Shaun Wilkinson / iStock.com
Swallowtail butterfly (Papilionidae)
Appearance: The swallowtail caterpillar is, like its adult butterfly form, a rare and spectacular sight. When fully formed, the swallowtail caterpillar has a bright green body with black bands, dotted with orange/red spots. Like the comma caterpillar, young swallowtail caterpillars also look like bird droppings. When threatened, they emit a foul scent using the orange scent glands behind their heads.
Diet: They feed solely on milk parsley.
When to see: Between May and July.
Where to see: They are only found in the Norfolk Broads, as this is the only place milk parsley grows.
Credit: KirsanovV / iStock.com & azndc / iStock.com
Elephant hawk moth (Deilephila elpenor)
Appearance: The elephant hawk moth has an impressive caterpillar. Named because of its likeness to an elephant's trunk, this chunky caterpillar is usually brown, although some are green in colour. It has large eye spots, a spiky tail and scale-like markings. This makes it look somewhat snake-like in appearance. When threatened, it can swell up, making itself appear bigger. The caterpillar will also make the most of its large eye spots if in danger.
Diet: It enjoys a diet of rosebay willowherb, bedstraw and Himalayan balsam.
When to see: This caterpillar is usually seen from July to September.
Where to see: It favours rough grassland, woodland rides and clearings, hedgerows and gardens.
Credit: Mantonature and Oliver Smart / iStock.com / Alamy Stock Photo
Small tortoiseshell butterfly (Aglais urticae)
Appearance: The small tortoiseshell caterpillar is long, black and yellow and covered in bristles. It uses the same technique as the peacock caterpillar to ward off predators.
Diet: It feeds on stinging nettles.
When to see: It can be seen from May to June.
Where to see: It is one of the UK’s most widespread species and can be seen in gardens and on stinging nettles.
Credit: Frank Hecker / Alamy Stock Photo & iStock.com / CreativeNature_nl
Emperor moth (Saturnia pavonia)
Appearance: The caterpillar of the impressive emperor moth is equally as impressive. It is bright green and covered in hairs and black-ringed yellow wart-like spots, sprouting from the body. These are known as spiracles: external openings which allow the caterpillar to breathe.
Diet: It feeds on the leaves of woody plants, including bramble, heather, hawthorn and blackthorn.
When to see: It is seen from May to August.
Where to see: It can usually be found in heathland, woodland edges and hedgerows.
Credit: TuomasMJP / iStock.com/ crossbrain66 / iStock.com
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