How moths become the masters of disguise

Butterflies and day-flying moths are a lovely part of our summer scene. But, I wondered, where do they go in winter?

It depends on the species, says the charity Butterfly Conservation. Some, such as the painted lady butterfly and silver Y moth, avoid our cooler months by migrating to southern Europe and North Africa, returning here the following summer.

Others, such as small tortoiseshell and peacock butterflies, prefer to hunker down indoors. You might find them overwintering in a shed or garage, or even your house.

If dark grey days make you want to sleep through to the spring, you might relate to the brimstone, which overwinters as a dormant adult butterfly. However, it doesn't need to buy a new coat as its body fluid contains glycerol and special proteins that act as an antifreeze, allowing it to withstand freezing temperatures naturally.

If you enjoy the great outdoors in all weathers, then you'll relate to the December moth which has a thick, furry body to trap heat. It’s a nice fur-lined coat to see it through the winter!

There are around 2,500 species of moth in the UK and many are outdoors through autumn and winter but often hidden in plain sight. You might say they are masters of disguise!

As the light begins to fade and summer flowers come to an end, the variety and splendour of the UK’s moths begins to wane slightly. But the variety of colours, shapes and patterns of moths aren’t just for show.

Moths’ appearance plays an important role in evading predators. Some use colour, patterns and shape to look like leaves or lichen, or even bird poo, so they blend in with their surroundings and avoid being spotted by predators. This is the case with the Chinese character.

Or they can be used to put on a display to ward off predators: bright colours might indicate that something could be toxic to eat, and “eye-spot” patterns, like those of the eyed hawk-moth, can startle those looking to make it a meal.

More colourful are herald moths, with warm shades of brown and burnt orange, reminiscent of a bonfire: their scalloped wings mimic dead leaves.

The angle shades moth can also go unnoticed amongst leaf litter. The chestnuts, feathered thorns, and barred sallows all add their own tones of rich brown, rust and ochre as disguise.

The pinks and greens of two moth species echo lichen-covered bark, exposed as trees shed their summer foliage in preparation for winter: merveille du jour (French for “Wonder of the Day”) and red-green carpet (named in the 18th century, when early entomologists were so impressed by its patterning they named it after a luxury woven carpet).

When the winter season arrives, the moths you might spot carry shades of brown, grey, or white, reminiscent of frost-tipped foliage, dead leaves, and bare branches.

They include mottled umbers, which fly from October into December with plain brown with dark speckling. Winter moths, flying from late autumn through to February, are a delicate pattern of pale brown and grey.

The December moth which, despite the name, can be seen flying from October until January, is charcoal grey-brown in colour with wavy creamy white markings.

Butterfly Conservation has a free downloadable “Moths by Month” booklet. It includes a “moths by month” chart and tells you how to discover which moths might be in your outdoor spaces. Get it here: https://butterfly-conservation.org/moths-matter/booklet

See also the UKMoths site (ukmoths.org.uk), a comprehensive guide with identification tips.