The record breaking painted lady is not the only British butterfly that migrates over long distances.
The large white (Pieris brassicae) is a powerful flier and can travel a long way from your allotment’s cabbage patch. In fact the butterfly laying its eggs on your kale may have migrated here from the continent. The British population is reinforced in most years by migrants from mainland Europe.
Header image: large white butterfly by Clive Knight (21.07.21 SCP-NR)
Butterfly migration is complex, the subject of much recent research and of sometimes contradictory conclusions. In general, it has been shown that large white migratory flights are northward from southern Europe and occur primarily during spring and autumn. Several generations will migrate several hundred miles northwards until stopped by falling temperatures in the autumn.
But despite this, large groups of Pieris brassicae are sometimes seen around the southern coasts of the UK in July, incomers feeding in nectar-rich old grassland. In the past such summer migrations could be enormous: in early July, 1508, there is a record of:
“an in-numerable swarme of whit buttarflyes, so thicke as flakes of snowe that men could not see the towne at foure of the clock in the aftarnoone, they flew so highe and thicke”