Whilst thousands of us head south to France and Spain for our summer holidays, high above us a colourful butterfly is heading in the opposite direction.
Painted lady butterflies migrate every summer from Africa and southern Europe to the British Isles and beyond, sometimes reaching Iceland. These resilient insects travel across Europe to lay their eggs on wayside plants such as thistles, nettles and mallows. Some stop to breed on the way, the second and subsequent generations boosting numbers arriving here and, in turn, producing offspring of their own.
It was once thought that this is a virtually one-way migration, with relatively few of the insects emerging here trying to fly to Africa. It was discovered a few years ago however that this is not so, most of the butterflies do move south in the autumn.
In 2009 nine million butterflies were estimated to have arrived here, and 26 million started the journey the other way. Using radar and on-the-ground observation scientists discovered that we had previously missed the returnees because they usually fly too high to be seen from the ground. They are only encountered when they land to rest, feed and breed.
The research also revealed that up to six generations can be involved in a round trip of 9,000 miles from tropical Africa to the Arctic Circle and back.
Butterfly Conservation’s Richard Fox said: " So we've kind of got this amazing creature right under our noses without really realising. This tiny creature weighing less than a gram, with a brain the size of a pin head, and no opportunity to learn from older, experienced individuals, undertakes an epic intercontinental migration.
Having said this, painted ladies are not the only butterflies and moths indulging in long-distance travel. In this country fellow-travellers include red admirals, two or three species of clouded yellow butterflies, and silver-Y and humming-bird hawk moth s.
This year a larger number of painted ladies than usual may be on the move. Look out for distinctive orange, black and white butterflies taking nectar from Buddleia and other flowers in gardens, parks and waysides. The adults are closely related to red admiral, small tortoiseshell (they are about the same size as these), and peacock butterflies. Faded looking individuals will be the long distance travellers, fresh and bright specimens will be the newly emerged generation.