With the onset of autumn, ladybirds are gathering in clusters on the insides of windows and in the corners of sheds, preparing to hibernate.
They sometimes accumulate in large groups, piled on top of each other, to protect themselves from the worst of the weather. As temperatures drop, their natural food supplies dry up and we see more ladybirds taking shelter indoors.
This film shows large numbers of ladybirds gathering at Woods Mill nature reserve in 2018.
Ladybirds are a successful group of insects, thriving in a variety of habitats including towns and gardens, grassland, woodland, farmland and heathland.
We have over 46 species of them in the UK, but not all are bright red with spots. Some are really quite dull looking and not instantly recognisable as ladybirds. Others have red spots on black or black spots on yellow and the number can vary from 2 to 22.
Our commonest and best-known is the Seven-spot Ladybird, which is easily recognised by its red wing cases and pattern of three spots on each wing, with one central spot touching both.
Enter the Harlequin
In recent years, Britain has become home to the Harlequin Ladybird too.
Harlequins can be hard to identify, as they can have over a hundred different colour patterns with different numbers of spots on their wing cases. However, they are never smaller than 5mm long, and have distinctive orangey-brown legs.
Native to eastern Asia, the Harlequin is one of the most invasive insects in the world. They were introduced in Europe to feed on and control aphids, and made their way to the UK in 2004.
Unfortunately, they don’t stop at eating aphids. The eggs of other ladybirds, as well as those of butterflies and moths, are also targeted. As such, they outcompete the UK’s own native ladybirds for food, which may be contributing to the decline of our native Two-spot Ladybird.
However, don’t be tempted to try to destroy these interlopers if you find a group on your windowsill, as there are often native species mixed in with large clusters.
Colourful warnings
The bright colours of many ladybird species warn potential predators such as ants and birds that they won’t make good eating.
When attacked, ladybirds exude a yellow fluid called ‘reflex blood’, which is very smelly and contains toxins that make ladybirds off-putting to many predators.
Their capacity to munch aphids make them a friend to the gardener, with the Seven-spot eating up to 5000 aphids during its year-long lifespan.
It’s a good reason to resist tidying up flowerbeds until the spring, as seed heads, hollow plant stems and leaf litter provide perfect homes for ladybirds to sleep in through the winter.
Another way to help hibernating ladybirds is to provide a home for them by drilling holes in a log or block of wood and placing it on a wall or fence near to plants in need of aphid control.
If you’re lucky you may be rewarded by a ‘loveliness’ – yes that’s a recognised collective noun! – of ladybirds where you are.
A version of this post was originally published in 2018.
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