Every autumn my house gets infested with Harlequin ladybirds. Harlequins should not be confused with the smaller, dainter British ladybird. Harlequins are a larger, aggressive non-native species from Asia which do some good stuff like eating plant destroying aphids but then they go and ruin it by attacking our native ladybirds.
In the summer the Harlequins spend the summer outside and I forget about them. But now they’re back. They live in an upstairs sash window and huddle by the dozen in the corner of the ceiling. The Harlequins aren’t daft. It’s no co-incidence that they’ve made their home a south-facing window above a radiator. When the heating is on the Harlequins bask in a climate hotter than Bangkok.
There’s not that many now but the trouble is once the Harlequins snuggle down for the winter they release pheromones to signal to all their Harlequin mates to join them in the cosy crevices of the sash window. Very soon I’ll be invaded. Harlequins will start to fly around the house, looking for their mates. They rest on the curtains, sofa, even a bare arm. By November I’ll be vacuuming dozens of tiny red carcasses off the floor.
The invasion of the Harlequin ladybird is a relatively new phenomenon. The first Harlequins in the UK were discovered in Essex in September 2004 and have rapidly spread across England, although they are much less common in the north and Scotland.
In the US Harlequins were introduced in the agricultural industry to eat aphid-destroying crops. However once the aphids had been scoffed the harlequins turned their attention to other species of ladybird.
Harlequins come in many colours and have a variety of spots but here are tips for identifying a Harlequin from the Harlequin Ladybird Survey website:
How To Identify A Harlequin Ladybird
- If it’s red with precisely 7 black spots, it is a 7-spot ladybird.
- If it’s less than 5 mm (1/5 inch) in length, it is definitely not a harlequin ladybird.
- If it has white or cream spots, it is a striped ladybird, an orange ladybird or a cream-spot ladybird.
- If it is large, burgundy coloured and has 15 black spots, it is an eyed ladybird.
- If it has an orange pronotum, and fine hairs all over the elytra, it is a bryony ladybird.
- If it is black with four or six red spots, two of which are right at the front of the outside margin of the elytra, it is a melanic form of the 2-spot ladybird.