By day butterflies delight and dazzle, but during the night other winged marvels are equally impressive. Anna Pike reports on how Britain’s moth populations are doing, with a visit to a garden in Stretton-on-Fosse during lockdown. PHOTOS: MARK WILLIAMSON
During the warm spring and early summer weather, people have been noticing lots of butterflies as they take their daily exercise. They may not be aware that the butterflies’ nocturnal relatives – moths – are even more diverse and equally spectacular.
Britain has approximately 2,500 species of moth, ranging from tiny micro-moths that are dwarfed by a fingernail to spectacular hawkmoths with a wingspan the width of an adult’s palm.
Across the country, enthusiasts have been getting their natural history fix during lockdown by running moth traps in their back gardens.
The traps are simple boxes fitted with a funnel, over which a light is suspended. Special bulbs emit short wavelengths of light which are particularly attractive to nocturnal insects. Moth-trappers fill the trap with empty egg boxes, which provide convenient spaces for trapped moths to rest until they can be identified and released unharmed in the morning.
Professor of ecology Owen Lewis, who works in the zoology department at Oxford University, has been running a moth trap in his small back garden in Stretton-on-Fosse for the last 16 years, ably assisted by his three teenage children Tom, Lily and Joe and his wife Anna, also a scientist.
So far Owen has recorded more than 200 different species. By submitting records to the national moth recording scheme he is contributing to long-term studies into trends in moth abundance and distribution.
Moths help to indicate changes to the wider environment, and they and their caterpillars are important as pollinators and food for other wildlife, including bats and birds.
The charity Butterfly Conservation has found that many moths are declining – estimates are that populations have declined by about 25 per cent in the last 50 years – while a few distinctive species have increased. The spectacular scarlet tiger moth, for example, which flies by both day and night, was rarely seen in Warwickshire before the early 2000s but is now a common sight.
“This year has been particularly good for hawk-moths,” says Owen. “Up to four different types have been visiting the trap in a single night, including the spectacular privet hawk-moth and the psychedelic pink and green elephant hawk-moth.”
He adds: “One of the joys of mothing is the variety of bizarre and inventive names given to these insects, often by Victorian naturalists. Some of my favourites are the Setaceous Hebrew Character, Maiden’s Blush and the difficult-to-identify The Uncertain.”
Asked to name his favourite species of moth, Owen demurs: “All of them. Obviously the hawk-moths are impressive. And don’t forget caterpillars – with even the dullest brown moth, quite often the caterpillars are spectacular as well. They’re such interesting creatures, they’re eating machines and can be hairy, brightly coloured, toxic… you name it.”
Owen first discovered the delights of mothing on a camping holiday in Pembrokeshire as a very small boy. He says: “I found a garden tiger moth – which has now become quite rare – and I put it in a margarine tub, where it laid loads of eggs. I ended up rearing hundreds of caterpillars, feeding them on nettles.
“Then I was hooked on keeping caterpillars and hunting for insects. My dad was a big influence – he was a biology teacher, although he was into plants more.”
Owen says: “Moths are good bellwethers of change. They react to changes to the countryside. Some of the decline in populations is linked to the way grasslands are managed, for example – the intensification of farming.
“Caterpillars and moths are important food for the birds at this time of year, such as blue and great tits who were feeding their young with them a few weeks ago. So if you want to see healthy bird populations you need to see healthy insect populations.
“Most British bats feeds on moths so they are quite important in that regard. Moths are also pollinators – we’re not aware of them as much as we are, say, bees but they are equally as important for some plant species. They do their pollination at night so we’re not seeing them visit all these flowers.”
To sample the delights of the nocturnal moth scene, you don’t need to invest in an expensive trap: a simple outdoor light over a white sheet can attract all sorts of unexpected “butterflies of the night”. Owen adds: “Don’t worry – they won’t eat your carpets.”
To find out more, visit https://butterfly-conservation.org