They have bright yellow legs, are about 25mm (almost 1in) long, and a single colony, if left unchecked, can “butcher” 90,000 pollinating insects in just one season. Since the first UK sighting in 2016 of Vespa velutina – the Asian or yellow-legged hornet – beekeepers and scientists have waged a vigorous campaign to minimise the damage this invasive species can do to Britain’s biodiversity and bee colonies. Last year, a wet spring and washout summer appeared to have hindered the insect’s population growth as the number of nests spotted in the UK dropped from 72 in 2023 to 24 in