Thanks to volunteer Robert King for his wonderful report and photos
It’s National Moth Week - a chance to celebrate the fantastic diversity of native moths.
Many people think of moths as small, drab and boring – insects that eat the clothes in your wardrobe. Whilst there are a couple of species whose caterpillars are partial to a woolly jumper (their niche in the wild would be living in birds’ nests and such), the concept of moths as drab and boring couldn’t be further from the truth.
Moths are the close relatives of butterflies, in fact so closely related that the answer to the question what’s the difference between a moth and a butterfly is rather vague! Whilst the butterflies are all day flying, there are day flying moths too.
Day flying moths: Six-spot Burnet (left) and Yellow-shell (right)
Butterflies all have clubbed antennae, but some families of moths have this too, to some degree. Some butterflies are brightly coloured, but equally there are drab butterflies (such as the Meadow Brown) and there are moths with colours and patterns that rival the most flamboyant butterfly. The typical shape of a butterfly is replicated by some moths (amongst a suite of other shapes) so that doesn’t distinguish them either. The most convicing answer to the moth vs butterfly question is perhaps a technicality of how the pairs of wings are hooked together. In short, both are members of the order Lepidoptera, which means scaly wing in Latin – a reference to how the patterns and colours of their wings are made from thousands of tiny scales.
Whilst there are only about 60 native butterflies in Britain, there are over 2500 moths, from the huge Privet Hawkmoth (below left), which has a wingspan as wide as your hand, to tiny micro moths that you need a hand-lens to see clearly.
Privet Hawkmoth (left) and Cocksfoot Moths enjoy a party on a flower (right)
For me, one of the most fascinating aspects of moths is their strategy for survival and how that creates remarkable diversity in their shape, colour and patterns.
A moth starts life as an egg. This hatches into a caterpillar – an eating machine which grows dramatically in size. The next task in life is to find somewhere safe to pupate – the insect undergoes metamorphasis, the body breaks down and re-forms into an adult moth. Once free from the pupa, the moth pumps up it’s wings, allows them to dry and is ready for take off. The task now is to disperse, find a mate and breed. But how do you go about this without becoming a tasty snack for a bird?
Some moth species have gone for a camouflage strategy – evolving with colours that allow them to blend in with their surroundings and hide in plain sight.
Green Silver-lines (left) and Large Emerald (right), two moths that have good camouflage against fresh green leaves
A Poplar Grey (left) has mottled markings which break up the shape and it blends in well when resting on stone or bark. The elegant Silky Wainscot (right) hides on wetland vegtation.
It’s not just colours that provide camouflage, many moths add to the illusion with body shape. The tufts and protrusions on the wing and body of these Pale Prominent (below left) and Beautiful Golden-Y (below right), along with their habit of holding their wings together like a tent, help disguise their presence.
When at rest, this Angle Shades (below left) holds its wings in such a way that it it closely resembled a shrivelled leaf. The Plume Moths (below right) take this trick to extremes – their wings are rolled up so that at rest it resembles a letter T.
As spring turns to summer, then autumn, you need a different set of colours to blend in properly. The moths of autumn can be spectacular – all manner of oranges and yellows to blend in with dying leaves. This fabulously named Canary-shouldered Thorn (below left) is easily mistaken for an autumn leaf. The trailing edge to the wings of the Scalloped Hazel (below right), break up the outline and ensure that the moth can rest uninterrupted during the day.
I sometimes wonder just how self-aware moths are – did this Common Carpet (below) deliberately align its markings along the stem?
If there’s competition for the moth with the ‘best camouflage using colour and shape’ I think the top spot would be tied between two superstars – the Buff-tip (below left) resembles a snapped off Birch twig, whilst the Poplar Hawk-moth (below right) has a wacky wing and body shape that is hard to beat!
Some moths have a double strategy to avoid capture – forewings camouflaged but, if a bird does spot them, they suddenly open their wings to reveal brightly coloured hindwings. This would startle the bird giving the moth precious moments to make an escape.
The Brown-tail moth (below left) takes hiding in plain sight to new levels – it looks very much like a stray feather. But even that is supassed by the tiny Chinese Character (below right) – when at rest it looks exactly like a bird poo, no bird would want to eat that!
A completely different strategy is not to hide at all. The Emperor Moth is a large day-flying moth that could easily be mistaken for a Small Tortoiseshell. It flies over heathland and open woodland. It’s rather too late in the year for them to be on the wing right now – they fly in April and May. Both sexes have prominent eye-spots on the wings. These could serve two purposes. Firstly, the eye spots draw attention away from the body of the moth – if a bird pecked at the eye spot, then the moth might loose a section of wing but could perhaps still escape. However, I think that the second purpose is that, from above, the whole moth looks like the head of a small mammal. The photograph on the left below shows a male Emperor Moth (admire those fabulously feathered antennae!) the photograph of the female on the right has been turned upside down – quite convinving as a mammal don’t you think?
If I was a bird flying overhead and noticed that, I’d likely be fooled that it was a fierce Stoat or Weasel rather than a juicy moth!
In nature, red or yellow is often a danger colour – indicating something that is poisionous or dis-tasteful. The caterpillars of the Cinnabar moth feed on Ragwort – a poisonous plant. The colours of the moth indicate to birds that they are poisionous and should not be eaten. The adult Cinnabar is equally as colourful and gives the same advice, so the moths are able to fly freely during the day without being eaten.
Caterpillars and adult Cinnabar moth
The Tiger moths have the similar poisonous or distastful properties, their use the danger colours gives them an appearance that rivals the beauty of any butterfly.
Cream-spot Tiger (left) and Ruby Tiger (right)
If you are planning to take part in the Big Butterfly Count, then remember to look out for day flying moths – these can be recorded as part of the count. How many can you find?