Scientists are on the lookout for an Asian beetle that could ravage British trees after one was found last week, the Food and Environment Research Agency (Fera) said today.
The Citrus Longhorn Beetle was found at a school in Langham, near Oakham, Rutland, Leicestershire, last week.
The beetle, occasionally imported with trees accidentally, devours native broadleaved trees and shrubs and an outbreak could seriously threaten UK horticulture and forestry, Fera said.
A spokesman said scientists are now hunting for the host plant in case there are more in the area, although currently it is only considered a finding and not an outbreak.
He said the beetle was found at Langham Church of England Primary School last Thursday and was identified by scientists on Monday.
They are 20-40mm long, shiny black with white markings and their long, black antennae have pale blue or white rings.
Adults lay eggs just under bark and larvae bore into wood. They take up to four years to grow so are difficult to detect, Fera said today.
The spokesman said a range of deciduous trees and shrubs can be hosts, although all UK findings so far have been on Japanese maple (Acer palmatum).
Derek McCann, from the Plant Health and Seeds Inspectorate, said: "To rule out the existence of an established colony of this pest we need to look at all possible host plants within a 100 metre radius of the original finding, including private gardens.
"In the meantime we would like to ask members of the public to be on the alert for the beetle and let us know if they find anything."
Fera said two other findings were reported this year by members of the public at Haydock, Merseyside, and Hastings, East Sussex, and both emerged from Acer plants in their back gardens bought two years ago.
The first sign of an infestation is often between May and October when an adult beetle emerges from a hole about 10mm in diameter. The holes may be found just above ground level in stems and roots, and other signs include chewing damage to leaves and bark or sawdust-like debris from the trunk.
Fera today urged members of the public to report suspected sightings or captures to its Plant Health and Seeds Inspectorate at 01904 465625 or http://www.defra.gov.uk/fera.