A ladybird rests on a leaf

Harlequins are usually identified by their orange legs © Shutterstock.com

Harlequin ladybirds are waking up from hibernation - here's what to do

A non-native beetle, the harlequin ladybird (Harmonia axyridis) was introduced to the UK as a form of natural pest control. Hanging out in swarms, eating other ladybirds and crawling around with an STD, just how dangerous is the harlequin exactly?

What do they look like?

Harlequin ladybirds are the same size as native ladybirds, sometimes a little bigger. They range in colour and pattern, but some of the most common forms are black with red spots, red with black spots and orange with black spots.

Harlequins have two white spots on their thorax. Unlike native ladybirds, however, most have a brownish underside and orange legs, which makes them fairly easy to distinguish. 

An example of a black harlequin ladybird

Harlequins are commonly black and are sometimes called black ladybirds © Shutterstock.com


The 'dangers' of harlequins

Harlequins have attracted negative publicity since they were introduced in Britain 2004, but in reality they are nothing to worry about.

They are known to reproduce quickly, gather in large swarms and compete with native ladybirds for aphids. They have shown signs of cannibalism, consuming the larvae and eggs of other ladybirds. But disease and predators are bringing the population under control.

Occasionally, a ladybird will bite humans if provoked, but it is harmless and causes no more than a minor irritation.

Harlequins can also carry an STD called laboulbenia. It is a fungus that forms little scales on the wing cases, and sometimes white crust on some parts of the exoskeleton, which can be seen with the naked eye.

The STD also infects native ladybirds - the harlequin is simply another host for the fungus to live on.

The good news is humans cannot be infected.

A group of harlequins ladybirds clustered inside a crack in rocks

A swarm of ladybirds © Shutterstock.com


Harlequins in your home

Adult harlequins generally hibernate individually in cracks within barks or rocks over the winter. As the weather warms, they will be waking up to mate and lay eggs, so sightings will be frequent.

It is common to find them in your home. If that is the case, there is no need to kill them - they are harmless.

Dr Max Barclay, Senior Curator of Beetles at the Museum, says, 'These ladybirds don't want to be in your home any more than you want them there. If people squash them, they can stain walls with their defensive yellow chemical secretions which can be slightly smelly.'

The best thing one can do is 'to help them find their way out,' Max adds. 'The ladybirds will be grateful, and may even repay the favour by eating some of the greenflies on your roses.'

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Identify nature

If you spot any wildlife in the UK that you'd like to find out about, the Museum's identification team can help.