Butterfly Invasion!

Publish Date: Tuesday October 1, 2019

Did you see any Painted Ladies this summer? They were here in their millions, you might have seen them crowded onto Buddleia bushes with a few Red Admirals and Peacocks for company.

Painted Ladies are one of the most widespread butterflies in the world and they have an astonishing migration pattern. They cover thousands of miles in a kind of relay between generations, flying from North Africa to Northern Europe in up to six successive generations in spring and summer. The last big invasion was in 2009. These mass migrations must be controlled by weather conditions and plant growth along the way from Africa and this year the conditions must have suited the butterflies very well.

The female butterfly lays a single egg in the centre of a selected leaf, usually a thistle in Scotland. This is probably the secret of their success, they use a huge variety of common plants for their food. The tiny eggs are about the size of a pinhead and when the caterpillars hatch, each one joins the sides of its leaf together with sticky silk, making a little tent to protect itself. Then it slowly eats its tent! They grow fast, and when they are fully grown they attach themselves to a stem and grow a hard case called a chrysalis. Inside this case they liquidise and re-assemble themselves into a butterfly. It’s natural magic and only takes a few weeks.

The Painted Lady in the photograph is looking a bit tattered and worn. Long journeys and life among thistles will do that to you.

Find out more about Painted Lady migration mysteries and Citizen Science here.

Jan Hendry (Senior Countryside Ranger)