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Devon’s hidden insect migration

©Derek Moore

Every year, as the seasons change, many animals migrate in search of food, suitable habitats and breeding grounds. We often think of swifts soaring through our skies or humpback whales travelling across oceans, but what about insects?

Each spring, Devon experiences a largely unseen influx of migrating insects. Carried on warm southerly air currents, the same weather systems that sometimes bring Saharan dust, huge numbers of butterflies, moths and flies move north from southern Europe and even North Africa.

This is not a rare or exceptional phenomenon; it happens every year. However, the scale of this migration is often underestimated because much of it takes place high above our heads or under the cover of darkness, making it largely invisible to the human eye.

What you can spot in spring

Here are a few key spring migrant insects to look out for:

Painted Lady butterfly

Painted Lady ©Gillian Day

Painted lady butterfly
Once thought to overwinter in the UK, the painted lady is now known to be part of a remarkable 9,000-mile migration between North Africa and northern Europe. This journey is completed over multiple generations, with each generation leapfrogging the next on its way north. 

Red Admiral butterfly

Red Admiral ©Guy Edwardes/2020VISION

Red Admiral butterfly
The red admiral is a striking black-and-red butterfly often seen in gardens feeding on flowers on warm days throughout the year. Most seen in late spring are fresh arrivals from southern Europe, though some now hibernate in the UK.

Silver Y moth

Silver Y ©Bruce Shortland

Silver Y moth
An estimated 220 million can reach UK shores in spring. Seen throughout the year, it is very common in gardens and grasslands. It can often be seen flying during the daytime, feeding on nectar from plants, such as buddleia and lavender, but also flies at night.

Humming-bird Hawk-moth

©Derek Moore

Hummingbird hawk-moths
Migrating from southern Europe each year, this moth can often be seen during the day hovering over flowers, such as red valerian, while feeding with its long proboscis. Its wings beat so rapidly that it produces a distinctive humming sound.

Jon Hawkins – Surrey Hills Photography

Jon Hawkins – Surrey Hills Photography

Hoverfly
One of the most abundant yet overlooked migrants, hoverflies travel in huge numbers between Britain and continental Europe each year - up to 4 billion in each direction. They are vital pollinators, and their larvae eat vast numbers of aphids, making them extremely important for both nature and agriculture.

2026: A Remarkable Year for Migrant Moths

This year has seen exceptionally high numbers of migrant moths. In May, warm air flowing north from Africa brought not only sunny weather but also vast numbers of moths, carried hundreds of miles on the wind.

The next two species have generated particular excitement within the moth community:

a brown moth with a furry head

Credit - Simon Stennett, Devon Wildlife Trust

Eastern bordered straw moth (Heliothis nubigera)
This moth may not look particularly remarkable, but it is a very rare immigrant. First recorded in the UK in 1958, it has only been seen a handful of times in Devon since. It is native to southern and eastern Europe, North Africa and the Middle East.

In 2026, an unusual influx has been recorded across Britain, with multiple sightings. This image was captured by our Director of Nature Recovery after it was found in his moth trap at home in Devon.

on a large branch, the stripy moth with is wins slightly open

Credit: Ben Sale from flickr

Striped hawk-moth (Hyles livornica)
This striking moth is a scarce but regular migrant to southern Britain, originating from Africa and southern Europe. Numbers can increase during periods of warm southerly weather, and recent warm spring conditions have led to more sightings across Devon.

Our Director of Nature Recovery, Simon Stennett, reflects on the incredible journey of these migratory insects:

“When conditions are right, these migrations become visible. I was on one of our North Devon Culm reserves during the heatwave and, with each step, I was flushing clouds of silver Y moths from the vegetation, while painted ladies fed intensively or continued moving north. Some of the arrivals looked more worn and drab, their wings tattered after the long journey they had completed. It’s incredible to see these creatures back and fluttering across our Devon landscapes.”

 

Each year, billions of insects connect continents, habitats and seasons, often without us even noticing. It is one of the world's greatest migrations, unfolding across our fields, gardens and countryside. It may not seem as spectacular as the great wildebeest migration across the Serengeti, but it is just as extraordinary.

The familiar buzz and flutter of insects are welcome signs of spring and summer, yet they do far more than mark the changing seasons. They pollinate wildflowers and crops, recycle nutrients, and provide a vital food source for birds and other wildlife, making them essential to healthy ecosystems.

Sadly, insect populations are declining worldwide, with around 41% of species now threatened with extinction. The good news is that we can all play a part in their recovery. By planting wildflowers, reducing pesticide use, and learning more about these remarkable creatures, we can help provide the food and habitats they need to thrive and offer a safe haven when they return from their remarkable journeys to Devon.

Take Action for Insects

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