SWARMS of ladybirds have been invading homes across the nation.

Bigger than the ones we are used to, and possibly with black wings with red markings, rather than red wings with black spots - it's likely they are Harlequin ladybirds.

Spotted any in your house? E-mail photos to aslater@london.newsquest.co.uk

Dr Chris Terrell-Nield, principal lecturer in Ecology at Nottingham Trent University's School of Science and Technology explains more about the creatures and the so-called "invasion".

WHY IS THERE A LADYBIRD INVASION?

This isn't the first year we've talked about Harlequin ladybirds. In fact, as Dr Terrell-Nield notes, they've been here about 12 years, with early sightings dating back to 2004, in Essex. "It's one of these rather sad biological control stories, really. They come from the Far East originally, brought over to Europe as a biological control for pests on crops - things like aphids," he explains. "But they were never introduced to the UK. They flew here from the Continent, and since then, they've spread to cover the whole of England and Wales and bits of Scotland."

A THREATENING SPECIES?

"They can be, yes. Like all ladybirds, they're very predatory, and they're also a big ladybird - about the same size as a British seven spot ladybird, and that's one of our biggest ones - and they eat the larvae of smaller ladybirds. They particularly affect things like two spot ladybirds."

POTENTIAL ISSUES

The UK has around 40 species of ladybird and they play a part in pest control in gardens and for crops. "And this invader comes in and upsets the system by destabilising existing populations," notes Terrell-Nield. "[The Harlequin] likes certain habitats which the others don't necessarily tend to inhabit. So it can live somewhere they can't, and also overflow into their habitats and displace them. It could have quite a serious impact on our native ladybird diversity. It's probably the most invasive ladybird there is and spreads quickly. It also spreads a fungus when it mates, and if that gets out of the Harlequin population into the British ladybird population, that could be an issue."

LADYBIRD REMOVAL

If you want to avoid yellow stains - and nips - it's best not to handle them. "Use a dustpan and brush, or a hoover if you really want to get rid of them, and let them go outside," says Terrell-Nield. "In terms of a species, they're here, and they've spread pretty far. There's not much you can do which won't seriously affect other ladybirds - which we don't want [to happen]."

If you want to avoid yellow stains - and nips - it's best not to handle them. "Use a dustpan and brush, or a hoover if you really want to get rid of them, and let them go outside," says Terrell-Nield. "In terms of a species, they're here, and they've spread pretty far. There's not much you can do which won't seriously affect other ladybirds - which we don't want [to happen]."