Beauties and the beastly plant
Stunning splashes of colour flit in the air, and rest on our flowers, wings gently pulsing back and forth. But some butterflies are united not just by their eye-catching nature…
The Red Admiral, Small Tortoiseshell, Peacock, Comma, and Painted Lady are among our best-known, and therefore best-loved butterflies. But what else unites them, apart from that?
For starters, all five of them are from the Nymphalidae family (pronounced “nim-fa-lid-eye), better known as brush-footed butterflies. Look closely at them when they land, and you will notice that they stand on four legs only, and have two legs which they hold up that are far smaller.
This front pair of legs is useless for walking, and in fact scientists are unsure why the legs have developed this way. If you’re lucky, you will get a close look and see that they are covered in tufts of hair-like scales, called setae. It is these hairs that give the family the name ‘brush-footed’, and some experts believe these hairs help pick up scents, and so help with communication. Incidentally, males only have two joints in these legs, and females have four, so it’s a way of telling them apart.
There are around 6000 members of the brush-footed family, though, so there is something more specific that unites our famous five: they all rely on the stinging nettle. Nettles: An unlikely hero uncovered the reasons why nature lovers and gardeners alike should be celebrating the stinging plant. This time we concentrate on the butterflies that need it to survive.
Despite plummeting numbers in recent years, the Small Tortoiseshell is still one of our most common butterflies, and is often seen in gardens in cities as well as the countryside (the adult is particularly fond of buddleia). A resident species, it can be found across the whole of the British Isles including the more remote Scottish Islands.
The adults emerge from hibernation as soon as the days warm in spring, and immediately set about feeding and breeding. They are totally reliant on nettles for their entire breeding process.
First, the males will secure territories in a suitable sunny nettle patch each day. If another male passes, he will be chased off – watch out for Small Tortoiseshells spiraling dizzyingly around one another in flight, over nettles; it is a great sight, as the males fight it out.
If you spot a butterfly chasing a butterfly, rather than spiraling round it, then it will be a male giving chase to a passing female. Eventually, they will land on the nettle patch and mate.
Finally, the female will choose tender new nettle shoots in a sunny area to lay around eighty eggs. About twelve days later the tiny black and yellow caterpillars hatch, and immediately spin a silk tent around themselves and the nettle leaf, beneath which they can feed in relative safety.
As the caterpillars grow, so does the web-like tent; in fact, it becomes very noticeable indeed.
When the caterpillars moult for the last time, before they pupate, they become more solitary. They can be spotted sunning themselves on the top of leaves, or lying in a rolled up leaf, like their relative, the Red Admiral. They then find a suitable tree trunk, wall or hedgerow where they will pupate – often travelling many metres in their search. Cleverly, their chrysalis is spun to match their surroundings, and can vary from gold to brown, in a bid to disguise themselves from hungry Blue Tits. Twelve days later, the adult butterfly emerges.
Those that hatch early in the year set about breeding immediately, while adults that appear later in the year, from a second brood, feed themselves up, ready for hibernation (See Sleeping Beauties for more information on hibernating butterflies).
Without Nettles, Small Tortoiseshell will die out – they are the only plant their caterpillars will feed on.
Orange wings feature an easily recognisable pattern of pretty black and yellow markings, as well as blue spots in the dark borders of the wings. The beautiful upper wings contrast strongly with the dingy dark brown of the underneath of their wings.
Although a common feature of the British countryside, the Red Admiral is in fact a seasonal migrant. The adult butterflies have a tendency to hibernate in exposed places and so very few manage to overwinter in Britain. In Spain and North Africa there are resident populations that breed early in the year. Those adults and their offspring continue to move northwards with the improving conditions, breeding as they go, sometimes reaching Britain in small numbers as early as March. In good years this influx of mainland European adults, combined with their British progeny, can lead to large numbers of butterflies in the Autumn.
Chances are, the last butterfly you see of the year will be a Red Admiral. They can be found feeding on Ivy flowers as late as October and early November. It has a particular liking for overripe fruit that has fallen. Red Admirals can often be seen in orchards and gardens under apple and pear trees where they feed on the fallen fruit.
The eggs are laid singly on the upper leaves of nettles - usually in the middle of large patches. After about seven days the larva emerges and immediately folds a leaf together to make a sort of 'tent', securing the edges with silk. Within this structure the young caterpillar can feed in relative safety. When they have finished eating one such leafy tent they move on to another.
Several leaf tents are made as the caterpillar grows, each progressively larger. With experience these become quite easy to spot in the nettle patch. The spiny caterpillars come in two colour forms - black and a yellow green, both with yellow markings down each flank.
When fully grown the caterpillar chews part way through a nettle stem causing it to fall over. It then spins together several of these, now downward pointing, leaves to create a shelter in which to pupate. The adults emerge from the chrysalis, which is patterned with metallic gold spots, in approximately 12 days to continue the cycle.
There is no mistaking this beauty: it is a large, bold butterfly, with very dark brown and lack wings, boldly marked with bands of orange-red. There are also white dots on the wing tips.
This Peacock Butterfly is common all over the UK and also found in Europe and Asia as far as Japan.
The butterflies hibernate and so can be seen all year round, with some being still out late into the autumn and others freshly emerged in the early days of spring. If a bird comes across them whilst hibernating, they have a fantastic defence: the eyespots, which resemble an owl when viewed upside down, are flashed by the wings being shaken. At the same time, the forewings rasp together, creating a loud, grating noise. It is enough to put off many would-be predators.
Emerging from hibernation in the spring the males, like their cousins the Small Tortoiseshells, find themselves a sunny patch of nettles. They defend their patch with such vigor they have even been know to chase off birds. This behaviour can be used to identify the sex of the adults: throw a twig or stone above a male and it will invariably investigate.
After mating, the female lays around 200 eggs on new nettle shoots, in full sun. The resulting black, spiny caterpillars can feed on Hops, but are far more common on Nettles. Again, like Small Tortoiseshell, they spin a silken tent beneath which they feed. As they grow larger, though, they venture out from its safety and feed in large groups on nettles in the
sunshine; the writhing mass is an impressive sight that no doubt is off-putting to birds and mammals that would otherwise eat them (many, however, fall victim to spiders or parasitic wasps.
They only leave the nettles when they are ready to pupate under nearby vegetation. Pupae can be dusky grey or yellow-green, depending on their surroundings. Adults emerge after 12 days.
Adults hibernate, often in hollow trees or garden sheds, but will emerge on mild sunny days as early as January.
A striking butterfly, the Peacock is large, with dark rusty-red wings, each of which has a very striking eye-spot on it. The undersides of the wings are fabulous camouflage when the insect is resting, as it is the dark brown or black of a dead leaf.
Although this beauty cannot live in the UK (our winters are too harsh for it to survive in any part of its life cycle, from egg through caterpillar to adult) it is still widely seen, and synonymous with summer. It migrates here every year from North Africa and the Mediterranean, and can be found on every continent in the world apart from South America and Antarctica.
Caterpillars will feed on various types of thistle, and on hollyhocks, but its favourite by far is the stinging nettle.
It has salmon-pink wings marked with black and with dotted with white against a black background on the tips of the front wings.
From early March you will see male Commas, just emerged from hibernation, sitting on a vantage point in the warm spring sunshine. They will chase any passing females, and eventually mating takes place in a high shrub or tree.
Between the 1820s and the 1930s this butterfly was extremely scarce and could only be reliably found on the Welsh Border. The reason for its decline is unsure, but its thought to be linked to its main food pant, hop, being grown less as village breweries stopped operating.
Now it has made a remarkable recovery, and is common in woodland and garden alike – mainly thanks to the butterfly making Nettle its main larval food plant (although they will also feed on blackcurrant and gooseberry leaves).
The female lays a single egg on top of a nettle leaf in a sheltered spot, and 15 days later the brown caterpillars hatch. You will have to look closely to spot them though: when still, they look exactly like a bird dropping, right down to a big white splash at the rear of the form.
At this time of year, August, you may see some Commas which look a brilliant golden-orange, while others appear a darker, tawny-orange. Each has a different fate ahead of them. The golden ones emerged earlier this year and will breed now; their offspring will emerge in autumn but then hibernate almost immediately. The darker ones are busy feeding themselves up, ready to also hibernate in autumn, and won’t breed until next spring.
The Comma Butterfly has ragged edges to its wings, which make it look like a dead leaf when it is at rest. The upper surfaces of the wings are a rusty orange, with a large number of dark brown markings on them too. The underneath of the wings have a white, comma-like marking, which is how the butterfly got its name.