As I walked into our communal garden the other day I was startled by a large butterfly flying up from the tub of pansies by the door. I stood still and waited as it fluttered about and then settled again to feed. Then I recognised it, a Painted Lady.
Slightly larger than our native Tortoiseshell butterfly, they have similar colouring on the wings, mainly a red ochre colour with black and white markings. The Painted Lady is one of the most widespread butterflies in the world, being found right across the northern hemisphere including Africa.
It is also one of the great travellers and a match for the Monarch butterflies whose mass migrations have been the subject of many nature films. A worldwide citizen science project has tracked some of the migrations.
The main year-round population centres are at latitudes further south than the UK but, as the northern hemisphere summer starts, huge numbers in Mediterranean Africa move north. Although the butterfly in my garden will probably not have just arrived from North Africa. This is the origin of most UK summer visitors, but the butterflies stop off to breed on the journey. Most of the UK summer population were born in Southern Europe rather than Africa.
The routes flown and numbers arriving in the UK vary with weather patterns across Europe. Some years very few are seen even in southern England, but in 2019 the weather on route was favourable and an estimated 11 million arrived.
The life cycle in the UK can be complete in three to four weeks. Depending on the temperature, eggs hatch in 3-7 days, the caterpillars take 7-12 days to mature and pupate, and the adults emerge 7-14 days later. The main foodplants for the caterpillars are various thistles, sometimes mallows and nettles too. There will be at least two generations over summer.
Until recently, there were mixed views in the world of lepidoptery about whether butterflies born here in late summer just died off in late autumn or flew back south. The answer was provided by recent research at the Rothamsted Research Centre, scientists used radar to track large groups of the butterflies flying south but at very high altitude which would explain why they had not been seen before.
There are already numerous reports of sightings of these beautiful visitors across the south coast this year, perhaps this week’s early visitor to my garden signals another busy year.
Ed Dolphin
Related Posts:
