Watch out for swarms of “stinky” bugs threatening our wine, our native ladybirds and our noses as one of the most “invasive insect species in the world” invades homes.

The Harlequin ladybird, which took less than a decade to spread throughout the UK while the grey squirrel took 100 years to do the same, exudes an "unpleasant" smelling yellow fluid as a defence mechanism and has been multiplying in large numbers recently.

Due to the coming winter months, the insects are massing together in large groups for warmth and people have reported seeing swarms of them in their homes.

The UK Ladybird Survey warns the "voracious" appetite of Harlequin ladybirds originally from Asia is threatening the native ladybird as they eat other ladybird eggs and larvae and even bite humans when hungry.

These bothersome bugs can carry an insect STD, the Laboulbeniales fungal disease, which is passed on through mating and poses yet another threat to the native ladybird.

Even Christmas wine may be at risk as when Harlequin ladybirds are feeding up for winter they seek out ripe fruit and are “particularly fond” of grapes, with wineries noticing large swarms in the grape harvest.

Professor Helen Roy, of the Centre for Ecology and Hydrology, warned the ladybirds could also limit alcohol production.

She said: “'These ladybirds also feed on grapes so they are often found in vineyards which, of course, becomes a problem for wine production.

“Their powerful, defensive chemicals can affect the taste of wine if they get trapped in the production process."

Conservation ecologist for London Wildlife Trust Tony Wileman believes the overall threat to native species of ladybird is not as great as initially thought but localised areas, specifically urban areas such as London, will be most affected.

He said: “The impact tends to be in urban areas, they hibernate in buildings in large numbers where hundreds or thousands gather together.”

He added that when they experience a food shortage they can even “cannibalise themselves”.

When asked for advice on how to keep the insects out of homes, Mr Wileman said it was “almost impossible” and we had gone past the point of getting rid of the species.

He said: “If everyone killed 30 a day, we still couldn’t control it.

“They are here and they’re here to stay."

The Harlequin ladybird was introduced to North America from Asia in the 1980s to control plant lice and experts believe the insect may have been blown by strong winds to UK shores in 2004.

If you have any experience with Harlequin ladybirds in the South London area contact us at grainne.cuffe@london.newsquest.co.uk or 0208 722 6310.