The beetles have been discovered in a 'woodland setting' during "routine surveillance". The Government contingency plan has been initiated and the Forestry Commission has been designated the competent body for the outbreak.
Movement restrictions have been served on-site to minimise the risk of onward spread, while further investigations and surveillance of the area is conducted. Adult beetles will be dormant and hibernating at this time of year.
The eight-toothed spruce bark beetle does not affect human health but can be a serious and destructive pest of the spruce tree species across Europe, although it generally prefers weakened or damaged trees.
It has never been discovered in the wider environment in the UK before. Smaller spruce trees (less than fifteen years old), including domestic Christmas trees, are too small to be susceptible to infestation and very unlikely to be affected by this finding.
Nicola Spence, the UK Chief Plant Health Officer, said: "An outbreak of the eight-toothed spruce bark beetle (Ips typographus) in an area of woodland in Kent has been confirmed. It poses no threat to human health, but can be a serious pest of the spruce tree species.
"We are taking swift and robust action to limit the spread of this outbreak as part of our well-established biosecurity protocol used for tree pests and diseases.
"I encourage anyone who suspects a sighting of the bark beetle to report these to the Forestry Commission on the Tree Alert portal."
Caroline Ayre, of Confederation of Forest Industries, said: "The discovery of this outbreak is of great concern to the UK forest industry. It is essential that everyone is vigilant and we work with the Forestry Commission to help bring this outbreak to a swift conclusion."
Defra said it did not disclose the exact site of a recent pest or disease outbreak while surveillance is ongoing in the interest of responsible biosecurity. Defra does not want members of the public to access a site during the surveillance period when there are movement restrictions in place, saying to do so would increase the risk of the pest spreading. It will be able to identify the sites at a later date, once the essential surveillance work has concluded.