Since they were accidentally introduced to France in 2004, Asian hornets spread across the country into Spain and were first spotted in the UK in Gloucestershire two years ago. To date, there have been nine confirmed sightings in England and five nests have been destroyed by wildlife experts.Bee inspectors use infrared cameras and traps to locate and destroy any nests that pose a risk to domestic bees and their nests.The trust has stressed that people should follow the official guidelines on suspected cases and be aware of the threat of Asian hornets at all times.It recommends that the public should carefully photograph the insect without disturbing the nest and then submit an online sighting report to the GB Non-native Species Secretariat. Asian hornet queens are up to 3cm (1.2in) in length, while workers are up to 2.5cm (1in)Credit:Defra/PA “Our native hornets are slightly bigger, while Asian hornets tend to be smaller and of a darker colour, not yellow, especially on their thorax (middle section) and abdomens (tail section). However, it is easy to be confused, so our advice is always not to destroy a nest, but instead to report suspected sightings of Asian hornets to the NNSS, ” Mr Hussey added. Native European hornets are being ‘persecuted’ by over vigilant gardeners who are mistaking them for their invasive Asian equivalent, a wildlife trust has warned.Devon Wildlife Trust has said people have begun exterminating the European hornet (Vespa crabro) after confusing them for the predatory Asian hornet (Vespa velutina).Unlike its home-grown equivalent, the Asian species is known to wreak havoc to honeybees, with the insects routinely raiding and destroying colonies.Confirmed reports of Asian hornet nests in Devon and Cornwall have fuelled concerns among British beekeepers that the future of the honeybee is under threat.Steve Hussey, Devon Wildlife Trust spokesman said: “European hornets are a beautiful and vital part of our environment. They help us by helping to keep in check many insect species that gardeners consider to be pests. “European hornets are also struggling and their persecution is one of the factors behind this recent decline. Other countries are now urgently acting to conserve their remaining hornets; in Germany, for example, since 1987 it has been illegal to destroy a hornet nest. We need to look after our native population too.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.