WHILE walking into work the other morning I stumbled across something unusual on the footpath. I had spotted an alien invader.

Not of the extra terrestrial kind obviously, but an invader from another country, and one which is not only spreading quite successfully across the UK, but is seemingly quite damaging.

The alien is in fact a ladybird. But not the sort of creature normally associated with anything other than nursery rhymes and for being one of the gardeners' best friends.

This particular ladybird is known by a few different names, but most commonly the Harlequin or perhaps more descriptively the Halloween ladybird (Harmonia axyridis), its name coming from the pumpkin coloured wing cases of the most often seen form.

The Halloween ladybird originates from Asia, but was introduced to North America in the late 1980s as a form of aphid control. It is now the most widespread ladybird in America. What harm can a ladybird do I hear you ask.

Well, one of the biggest problems associated with it is that it is out-competing all the native ladybirds, lacewings and some butterflies for food, even reportedly eating butterfly eggs, lacewing larvae and other ladybirds.

It was introduced to Europe to control aphid pests and is spreading well there too. It arrived in the UK in 2004 and while it is not known exactly how, it more than likely would come to our shores as a hitchhiker in ships, and possibly through the Channel Tunnel. Although it is also possible it could have flown or been blown across from the continent.

Ignoring all its faults, it is superficially a pretty little beetle, being slightly larger than our common seven spot ladybird at approximately 7mm, and quite colourful, coming in three colour forms.

Firstly there is the pumpkin variety mentioned previously, a striking orange with black spots. The other two, are at first glance quite similar, and are also the ones you are most likely to confuse with our native ladybirds.

One form is glossy black with four bright red spots, two large and two small, while the other is glossy black with one large red spot on each wing case, each with a black dot in the middle, giving the appearance of eye spots.

However, the patterns on these ladybirds can vary and add to that the fact that there are 46 native species of ladybird and you can see where confusion may happen.

For this reason I would ask that you do not kill them, as they are particularly similar to the black form of our two spot ladybird.

There is a lot of interest in these alien ladybirds, particularly among ecologists, who would like people to record sightings on a website dedicated to tracking their spread across the UK.

This is so they can monitor how quickly the ladybird is spreading, and also look at the effect it is having on our native wildlife.

The specimen I discovered turned out to be dead, but it has been recorded anyway as it will still provide useful information.

If you are interested, visit www.harlequin-survey.org, there are identification charts, and instructions on what to do if you see one.

Who'd have thought it? Aliens landing in Kidderminster!