(Credit: Image courtesy of The Natural History Museum) This mystery bug has not been seen in the UK before and has made the Natural History Museum's Wildlife Garden its home. This is an immature specimen. image:41708:2::0

A small almond-shaped insect is residing in the Natural History Museum's Wildlife Garden. This newcomer has the Museum's insect experts baffled.

The mystery bug is red and black and about the size of a grain of rice and so far appears to be harmless, but there is the possibility that it will spread throughout the UK.

First seen in the Museum grounds in March 2007 on the seeds of some of the plane trees that grow there, there have been reports of similar specimens n 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."


The newcomer has been compared with those in the Museum's national insect collection of more than 28 million specimens and there is no exact match.


Closely resembling 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.

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."