TV gardener Alan Titchmarsh has urged English gardeners to keep an eye out for a pesky little insect which he said posed a threat to the British potato industry amid an outbreak of the invasive species. The Colorado beetle, which feeds on the foliage of potatoes and other plants, like peppers and aubergines, was confirmed in Kent after a laboratory diagnosis and marked the first known case in the UK in 50 years. Officials hope that the outbreak can be eradicated by the end of the year, but warned the public to remain vigilant to the threat.
Titchmarsh said: “It devastates potato crops and we need all the crops we can get in this country. It’s so savage, it’ll wipe crops out. It’s like locusts. It’s that fast.” Titchmarsh said the secret was to “stamp it out before it becomes reality”, adding: “There’s so much waiting on the doorstep.” Drew Swainston of House and Gardens magazine said: “The notion of a vegetable garden pest that rapidly breeds, over-winters in the ground, and whose larvae can decimate plants sounds like a nightmare to any grower. However, that is a fairly accurate description of Colorado potato beetles.”
“I have grown potatoes for many years in the UK, professionally for chefs and on my home allotment. While I have not experienced Colorado potato beetles first-hand, the pests continue to spread globally. All potato growers should know the pests’ distinguishing characteristics and signs to look out for and learn how to get rid of Colorado potato beetles.”
Colorado beetles severely weaken crops, such as potatoes and aubergines. Gardeners who spot the insect are urged to catch it in a container, if possible, and contact the Animal and Plant Health Agency (APHA) with a photo and location details.
The 6mm to 11mm beetle, which does not represent a risk to human health, is yellow or cream with 10 black stripes, and an orange head with irregular black spots. They are not permanently established in the UK but are easily brought in from continental Europe, particularly in the summer months. The beetles have been known to be imported into the UK on plants, such as leafy vegetables, salad leaves, fresh herbs, grain and frozen vegetables.
A single female can lay up to 2000 eggs, potentially leading to a colony quickly establishing if not detected.
Prof Nicola Spence, chief plant health officer at the Department for Environment, Food and Rural Affairs, added: “Colorado beetle poses a significant threat to plants and the wider potato industry. The public have an important role to play in helping us take swift and effective action to protect UK biosecurity.”
Potato plants can lose 15% of their leaf area without loss of yield, but an uncontrolled heavy population of Colorado potato beetles can kill all the potato plants in a field by mid-summer.
If a gardener finds a Colorado beetle in their vegetable patch or allotment in England or Wales, they should capture it in a secure container. To then report it to the Animal and Plant Health Agency call 0300 1000 313 or email planthealth.info@apha.gov.uk. Include a photograph and location details with the report. It is crucial not to release the beetle.
One gardener on a Facebook forum said: “I have these bugs on my potato plants and they won’t die. I know these bugs are devouring my plants. I’ve seen a few of the black and white potato bugs and I got rid of them but I can’t get rid of these.”
Plants you can grow that repel Colorado beetles include eucalyptus, catnip, marigold, nasturtium, coriander, onion, and tansy.