Cornwall told to watch for a hornet with orange legs

Check the ivy before you walk past it this week. If there’s a wasp sized insect working the flowers with a black body and legs that look dipped in orange paint, South West Water wants to hear about it.

It’s National Yellow-legged Hornet Week (7 to 13 September), and the water company is asking people across the South West to learn what the insect looks like and report any sighting, rather than leave it to beekeepers alone.

📷Credit: GB Non-native Species Secretariat

What to look for

The Yellow-legged hornet, also known as the Asian hornet, is named for its legs. They’re a distinctive yellow-orange, set against a dark abdomen carrying one standout orange stripe. It’s a priority non-native invasive species, first discovered in the UK in 2016 just 30 miles from Bristol, and numbers have risen sharply since 2023. September is the peak month to spot one.

A predator with a serious appetite

A single nest can get through around 11kg of native insects in a season. Do the sums since January and that works out at roughly 90,000 native pollinating insects eaten. The hornets prey on more than 1,400 species, hunting native bees alongside butterflies, bumblebees and beetles.

The scale of the problem this year is already on record. As of 3 September, the National Bee Unit had logged 167 Yellow-legged hornet sightings and 53 nests across Britain.

Not just a beekeeper’s problem

The responsibility to watch out for the hornets goes well beyond anyone who keeps bees. They pose a genuine risk to people too, and nests are turning up closer to where people actually are.

As a large landowner across the South West with its own responsibility for the natural environment, South West Water has been working with a range of groups to protect native biodiversity. That includes ongoing support for organisations such as the Somerset Beekeepers Association, supplying promotional materials to local beekeeping groups, backing conferences where research gets shared, and running outreach at community roadshows and events.

How to report a sighting

Sightings can be logged through the Asian Hornet Watch app. Once a report is confirmed, a specialist team funded by the government tracks the nest down and disposes of it humanely.

Rebecca Northey, a beekeeper and Invasives and Biosecurity Officer at South West Water, said the threat to native insects makes monitoring and management essential.

“There are also health and safety concerns as Yellow-legged hornets will defend their nests vigorously if disturbed, and unfortunately their nests are now being found in bramble thickets and places closer to human activity,” she said. “This is why we are encouraging all of our customers to download the Asian Hornet Watch app and keep a look out, especially on fallen apples and ivy at this time of year.”