Farmers have been warned after a “hitchhiking” beetle posing "a significant threat to potato crops" was discovered on UK soil for the first time in nearly 50 years.

The Colorado potato beetle has been found in a Kent field and confirmed by the Department for Environment, Food and Rural Affairs (Defra) and the Animal and Plant Health Agency (APHA) following lab tests.

It is the first time an outbreak of the larvae has been confirmed in the UK since 1977.

And while they do not pose a threat to human or animal health, if not eradicated, experts warn the bug poses a “significant threat” to potato crops.

The beetle larvae discovered on a farm in Kent has been formally identified as the potato eating insect classified as Leptinotarsa decemlineata.

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.

UK Chief Plant Health Officer, Nicola Spence, has called for farmers and growers to “remain vigilant” and report sightings.

She said: “Whilst this pest does not pose a threat to human or animal health we are responding swiftly through our eradication programme, involving ground surveillance to look for beetles and larvae at the outbreak site and surrounding area.

“We are encouraging all growers, farmers, processors and the public to remain vigilant and report any sightings, especially in Kent.”

With bright yellow or orange with black stripes the beetle is usually between 8.5-11.5mm in length and 3mm in width.

Meanwhile the 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.

A factsheet has been provided which details more information about the beetle’s life cycle andinformation on how to differentiate it from some of our native and introduced species.

The beetle is not native to the UK and is currently regulated as a Great Britain quarantine pest, with import and movement restrictions in place for susceptible host material.

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.