Mystery Insect Found In London's Natural History Museum's Wildlife Garden

The almond-shaped bug is red and black and about the size of a grain of rice. The bug appears to be harmless, but there is potential for it to spread throughout the UK.

Living on London plane trees

The bug was first seen in the Museum grounds in March 2007 on the seeds of some of the plane trees that grow there. There were also similar specimens found in other parts of London in 2006 that other scientists reported in a paper in May 2007.

The insects in the Museum grounds increased in numbers so quickly that by August 2007 it was the most common insect in the Wildlife Garden.

'It seems strange that so many of these bugs should suddenly appear,' says Max Barclay, one of the Museum's insect experts.

'With international trade and climate change, several new insects are showing up in London every year. Some of the invaders come from southern Europe, but others are from as far away as Australia. The fauna of the city is changing all the time now.'

Not even one in 28 million

Experts checked the new bug with those in the Museum's national insect collection of more than 28 million specimens. Amazingly, there is no exact match.

From alder to plane trees?

The bug closely resembles the fairly rare species Arocatus roeselii, which is usually found in central Europe. However, the roeselii bugs are brighter red than this new bug and they are usually associated with alder trees rather than plane trees.

However, the National Museum in Prague discovered an exact match to the mystery bug in their collections - an insect that was found in Nice and is classified as Arocatus roeselii.

'There are two possible explanations,' explains Barclay. 'That the bug is roeselii and by switching to feed on the plane trees it could suddenly become more abundant, successful and invasive. The other possibility is that the insect in our grounds may not be roeselii at all.'