Marvellous Moths

For many people, moths can be more pain than pleasure; eating our plants, damaging clothes, fluttering crazily around a light, but look a little closer and we discover fascinating creatures full of colour and adventure.

There are many, many more UK moth species, than their more obvious cousins, the butterflies (2500 compared with 60). Perhaps unsurprisingly, the butterflies get the attention – bright and colourful blooms which bring joy to the day and which are often celebrated in in our arts and culture.

And, little Butterfly! indeed
I know not if you sleep or feed.

 – William Wordsworth, ‘To a Butterfly’.

And yet our moths can be just as beautiful with subtle greys and greens engraved with intricate markings; delicate splashes of russets and pinks; bold flashes of gold and white; or gaudy flags of red and yellow.

I remember one of my first moth encounters as a child, finding a Garden Tiger exposed in the grass. Its striking black and white mottling and bright orange flashes are still deeply incised into my memory decades later. I was amazed that such a large and brightly coloured creature could be living in my back garden and yet rarely seen. This is the first fascination with moths, that they are often hiding in plain sight, with their bright colouration either hidden away or helping with their camouflage.

Moths are a great food source

Packed full of energy and protein, moths are an important food supply for many creatures. From birds hunting adults and caterpillars during the day, to bats catching adults on the wing during even the darkest of nights, moths must find ways to hide or evade these predations. It’s been calculated that a single pair of blue tits, for example, will catch up to 1,000 caterpillars every day to feed their growing chicks.

Experts at hiding

Moths have become experts at hiding. Mottled shades of brown, grey and black are ideal for those hiding deep in the undergrowth amongst dead leaves and twigs. Some of these like the Orange Underwing reveal their bright hind wings if disturbed. This might startle a predator long enough for it to escape or encourage the predator to fixate on the orange colour whilst in pursuit only to lose sight of its prey when the bright orange disappears, covered by dull brown forewings as the moth slips into long grass.

Some moths have taken this ‘startle’ to a whole new level. The Eyed Hawkmoth, for example, with its mottling of greys and olives blends very effectively into the bark of a tree, will flash its bright blue and black eyes if disturbed. It will even rock back and forth to strengthen the effect and discourage avian predators.  

For some moths, this bright colouration threat is very real. The Cinnabar Moth is perhaps the best well known as its black and red markings warn predators that it is distasteful and full of poisonous alkaloids collected from its food plant, Ragwort.

Other moths utilise surprisingly bright colouration to blend into their hiding place. Some like the Brimstone or Purple Thorn have striking yellow or red wings to mimic dying or damaged leaves, but the most stunning for me is the Merveille Du Jour. This pale green moth has deep black markings edged with white to give the effect of an intricate 3-dimensional structure, exactly like that of the lichen covered bark on which it hides.

Buff Tips are best

My personal favourite of all the moths has got to be the Buff Tip as, for one with such an unassuming name, this moth has got mimicry down to a T. Its silver-grey wings perfectly match the bark of a birch tree, whilst its light brown head and wing patches resemble the exposed ends of a broken twig. The magic is then topped off with its ability to hold its wings vertically, in wrap around fashion, to create a cylindrical shape. If knocked off its perch it will even stay in this position, playing dead while it rolls around your hand just like a snapped twig.

Hawkmoths can travel up to 12 miles per hour

The second fascination with moths is with their propensity for travel. When adult moths emerge from their pupa, they will often disperse to new areas in search of new food plants and mates. Sometimes, this can be over very large distances as with the Humming-bird Hawkmoth or Death’s-head Hawkmoth which can travel to the UK from North Africa. And whilst some of the weaker flying moths will seek out stronger winds to assist their travels, more powerful animals like the Hawkmoths can travel up to 12mph and maintain a straight line whatever the wind direction.

It appears that their main guide to navigation is from the moon or stars, but they can also utilise landscape features and a magnetic sense, especially useful in cloudy conditions. Transverse orientation allows the moth to remain in a straight line by keeping a bright celestial object at a constant angle. Unfortunately, this method now creates big problems for moths in our illuminated human landscape as distant celestial objects are replaced by much closer light sources. Replacing the moon as a navigational cue, our street and house lights quickly trap moths into ever decreasing circles of head crashing doom.

Declining numbers

It’s not just lighting which affects our moths which, along with many other insects, have experienced massive declines. Loss of habitat, intensive farming and the use of pesticides all contribute to biodiversity loss and these same issues also blight our gardens. According to Butterfly Conservation, in the 50 years since my sighting of that stunning Garden Tiger, numbers of this moth have declined by 90%. And it’s not just the moths themselves, as it seems the decline of the Cuckoo is linked to the decline in hairy moth caterpillars, like the Garden Tiger, on which it specialises.

There are lots of things you can do to help moths in your garden and, in turn, boost biodiversity on your patch. Try to minimise external lighting using timers, downlights, or avoiding them altogether and carrying a torch. Avoid the use of herbicides and pesticides and encourage a wide variety of different plants and flowers especially if these are native species. Why not allow part of your garden to grow wild, allow nature to take over and see what happens. And, of course, if you wanted to give wildlife a kickstart, choose a BioScapes® habitat unit to quickly create a wilder ecosystem.

How to set a moth trap:

One of the best ways to experience moths is to join an organised moth night. This will often involve a special moth trap and specialist mother (entomologist) and you will be able to encounter a whole range of different moths which can then be released safely back into the wild.

For a simpler method, simply shine a bright light onto a white sheet hung on your washing line. Very dark nights are best for this method, and, with luck, you’ll be rewarded with lots of moths and perhaps other insects like cockchafers and caddis flies.

A much nicer way to attract moths, for you and the moth, is through sugaring. Dissolving a kilogramme of sugar and black treacle into half a litre of cola or beer creates a pungent and tasty tipple which can be painted onto a fence or tree. Checking this after dark with a torch can reveal a number of patrons enjoying the brew.