The news that Colorado beetles have been found in a Kent potato field is a shock. The last time there was such an outbreak in the UK was in 1977, more than 45 years ago. Experts from DEFRA (Department for Environment, Food and Rural Affairs), the Plant Health and Seeds Inspectorate, are on the case, and also scrutinizing fields in a 1 km radius from the infestation. One beetle has also been spotted in Hampshire by a vigilant member of the public. So it is as well to alert readers how to recognise this beetle (see picture) with its spectacular orange and black stripes on the back. If you see one, phone the Helpline on 0300 1000313.
Its scientific name is Leptinotarsa decemlineata. A single fertilised beetle can establish a colony. It strips any plant of the nightshade family of all leaves. That means it also feeds on tomato and aubergine plants. It was first recorded in 1811 in the USA, and has since moved into Canada, Central America, Europe and Asia. It was spotted in Europe at Bordeaux, France in 1921, and has since spread to most European countries. But the British Isles has so far avoided this pest by strict quarantine. Our island status protects us! and the vigilance of the public and the inspectors. Occasionally it has been found on leafy imports and reported to the UK Plant Health Service.
There is more information in the Agriculture and Horticulture Development Board (AHDB) plant encyclopaedia. This is a comprehensive reference source for gardeners and farmers about all pests. It is the result of collaboration between growers and scientists. For pest control, it recommends:
- Prevent
This means crop rotation, sowing resistant varieties and using natural predators or plant enemies of the pest - Detect
This means trapping pests, ascertaining beneficial populations, monitoring thresholds - Control
This means reducing pest population to less harmful levels. Try physical and biological methods first rather than drastic chemical pesticides. Always be aware of plant protection and environmental risks.
In Ukraine, farmers have long battled against the Colorado beetle. They call it “Colorady”.
In 2014, when the separatists in the east of their country, in Donetsk, started making trouble, they were called “Colorady” in patriotic slang. The separatists often display a badge (the St George ribbon) that is orange and black, the same colours as the beetle, which is an unwanted pest.
