Every autumn, harlequin ladybirds cluster indoors to hibernate, sometimes in their thousands. Here is what is happening, and how to clear them out and stop them coming back. RSPH (BPCA) Level 2 certified and trainee technicians across the UK.
If you are suddenly finding large numbers of ladybirds gathering on sunny walls, around your window frames or up in the loft, you are almost certainly looking at harlequin ladybirds searching for somewhere to spend the winter. It happens every autumn, usually through September and October, and they can arrive in their hundreds or even thousands.
JG Pest Control are specialists in harlequin ladybird control and removal. Most ladybirds are harmless, but when they cluster indoors in large numbers they become a genuine nuisance. Our experienced, discreet and friendly technicians offer a guaranteed service across the UK.
Ladybirds are beetles, usually 1 to 10mm long and round in shape, with hard, brightly coloured and patterned fore-wings (elytra) and biting mandibles. The invasive harlequin species arrived in England around 2004 and has been spreading northward ever since.
The Harlequin (Harmonia axyridis), also called the Multicoloured Asian ladybird, is widely recognised as one of the most invasive insect species on the planet. Its appearance varies enormously, which makes it hard to separate from native ladybirds.
Look for a high number of spots on the elytra, often between 15 and 21, sometimes in a grid-like pattern, with an overall size of around 7 to 8mm. The wide variety of colour forms shown here is typical of the Harlequin.
For clusters that are already indoors, the most effective and honest approach is physical removal - vacuuming them up and emptying the contents well away from the house. Where numbers are very high, we make good use of the most up-to-date chemicals and organic solutions on the market, with a targeted space treatment of the cracks and crevices where ladybirds gather to bring things under control quickly. Our eradication service is guaranteed.
Because harlequins return to the same sheltered spots each year, lasting control combines removal with proofing of the gaps around windows, eaves and cavities that let them in. Our technicians will advise on the simple proofing measures that make the biggest difference for your property.
They are almost always harlequin ladybirds looking for somewhere warm and sheltered to spend the winter. As the weather cools in autumn they cluster on sunny, south and west facing walls, then squeeze in around window frames, into lofts and behind fascia boards. The same warm spots get reused year after year, which is why the problem returns each season unless the gaps are sealed.
They are not dangerous and do not carry disease. When food is scarce a harlequin may give a small, harmless nip if it lands on bare skin, but it is nothing to worry about. The real nuisance is the sheer numbers indoors and the marks they can leave behind.
When disturbed, harlequins release a little yellow fluid from their leg joints. This is called reflex bleeding and it is their defence against predators. The fluid has a distinct smell and can stain walls, curtains and other light fabrics, so it is best to vacuum them up rather than squash them.
Yes. The harlequin is an invasive species that arrived in the UK around 2004 and spread quickly. It outcompetes our native ladybirds for food and will even eat their eggs and larvae, which is why native numbers have fallen in many areas. Native ladybirds are harmless and good for the garden - it is the invasive harlequin that becomes a household nuisance.
For clusters that are already indoors, vacuuming them up and emptying the contents well away from the house is the cleanest method - squashing them risks staining and the smell. Where numbers are very high, our technicians can carry out a targeted treatment of the cracks and crevices where they gather to bring things under control quickly.
Because they return to the same sheltered spots each autumn, lasting control is really about proofing - sealing the gaps around window frames, eaves, soffits and air bricks before the weather turns in late summer. Our technicians will point out the entry points that matter most for your property and advise on the simple measures that make the biggest difference.
No, ladybirds are not a protected species. That said, native ladybirds are beneficial and best left alone in the garden. It is specifically the invasive harlequin, clustering indoors in large numbers, that is treated as a household pest.
Speak to one of our RSPH (BPCA) Level 2 certified and trainee techs today for free, no-obligation advice.
