Beetle larvae identified in a field in Kent was confirmed by DEFRA and the Animal and Plant Health Agency (APHA) as Colorado potato beetle (Leptinotarsa decemlineata).
Confirmation was made following laboratory diagnosis of samples taken by APHA’s Plant Health and Seeds Inspectorate. It is the first time an outbreak of the beetle has been confirmed in the UK since 1977, although they are endemic in large parts of Europe.
APHA is working closely with the affected grower to eradicate the pest from the site, including performing a 1km survey to determine whether there are further cases beyond the immediately infested area.
If not eradicated, Colorado potato beetles are a significant threat to potato crops. The adult beetles and larvae feed on the foliage of potato and other plants in the nightshade family and can completely strip them of their leaves if they are left uncontrolled. However, they are not a threat to human or animal health.
UK Chief Plant Health Officer Nicola Spence said: “Following a report, our experts have identified the presence of Colorado beetle larvae in a potato field in Kent.
“We are responding swiftly through our eradication programme, involving ground surveillance to look for beetles and larvae at the outbreak site and surrounding area.
“Whilst this pest does not pose a threat to human health, we encourage all growers, farmers, processors and the public to remain vigilant and report any sightings, especially in Kent.”
The beetle is not endemic to the UK and is currently regulated as a Great Britain quarantine pest, with import and movement restrictions in place for susceptible host material. APHA is obligated to act upon the current findings and eradicate this pest to support our efforts to maintain this status. Statutory Notices will be issued to ensure the containment and eradication of this pest is undertaken.
Farmers and growers in particular are being encouraged to remain vigilant for signs of the pest. The beetle is bright yellow or orange with black stripes and is usually between 8.5-11.5mm in length and 3mm in width. Its larvae are a reddish brown in colour, round and globular, and up to 15mm in length.
Although distinctive in appearance, there are several beetles that are frequently mistaken for them. The Colorado potato beetle plant pest factsheet provides more information about the beetle’s life cycle and provides information on how to differentiate it from some of our native and introduced species.
The beetles are occasionally imported into the UK from continental Europe as ‘hitchhikers’ on non-host plant material, such as leafy vegetables, salad leaves, fresh herbs and grain and are reported to the UK Plant Health Service who act on the findings. In the past 70 years, there have been two outbreaks of Colorado potato beetles in the UK, one in 1976 and one in 1977. Both outbreaks were eradicated shortly after detection.