You may have seen the harlequin ladybird already in your garden; it’s been in the UK for ten years now and is slowly advancing across the country from the southeast.
We already have a surprising 46 different species of ladybirds living in the UK, but this new one is bad news for many of them and experts are seeking the help of British gardeners to help track its invasion.
Why is the Harlequin ladybird a problem?
This new ladybird, the Harmonia axyridis is considered to be the most invasive ladybird on earth. Its recent arrival in Britain could jeopardize many of the native ladybirds in the UK. It can live in very diverse habitats so it can compete with other ladybird species in their chosen territory for food. It will also eat other ladybird species, as well as usual ladybird food such as aphids and scale insects.
What does a Harlequin ladybird look like?
Ladybirds are small beetles, usually round or oval in shape. They have hard forewings called elytra, which are usually brightly coloured and patterned. The Harlequin ladybird also called the Halloween ladybird or multi-coloured ladybird can be very variable in its appearance. This can make it a bit tricky telling it apart from our friendly native ladybirds.
Not all of our native species are brightly coloured and spotty, some in fact are quite dull looking and don’t really look like ladybirds at all. The most common species in Britain is the 7-spot ladybird.
You can find some useful images and information on the Harlequin Ladybird survey site. There’s also a ladybird identification sheet to help you distinguish the harlequin ladybird from other native British ladybirds.
Generally the harlequin ladybird is a bit bigger than our native ladybird species. The most common types are orange with 15-21 black spots or black with two or four orange or red spots, but there is huge variation.
What to do if you see one?
The invasion of the harlequin ladybird (Harmonia axyridis) threatens our native ladybirds and other species. The UK ladybird survey has been collating records of sightings of these insects over the last ten years. It has used these records to explore the ways in which our native ladybirds are responding to the harlequin ladybird. If you want to know more about the harlequin ladybirds you can read more here.
There is no recommended control for these insects, in fact they will devour a wide range of garden pests in your garden, so killing them is rather futile, you may as well benefit from their bug busting potential. The harlequin ladybird is such a successful insect and breeds prolifically, so squashing a handful isn’t going to solve the problem. What’s more, unless you are absolutely certain of the identity of what you have found, you may mistake a native ladybird for an invader. So in essence, they are best left alone. Instead help monitor their spread and leave the rest to the experts.