The first thing it is important to make clear is that when we talk about Asian hornets we are using a ‘common name’. Common names can cause confusion. For example, when someone in the UK calls a bird a ‘robin’ they are referring to the small, crimson-breasted bird on Christmas cards, but in the USA ‘robin’ refers to a larger species of thrush. Likewise, ‘Asian hornet’ is often applied to two species of large social wasp. Only one of these species is relevant to Europe, but both hornet species are invasive.
The species we are concerned with in Europe has the scientific name Vespa velutina. The other species commonly called the Asian hornet (more correctly Asian giant hornet) is the larger Vespa mandarinia. This species is found in many parts of Asia but has recently been discovered in the Pacific Northwest of North America. The hornet’s size (4.5cm long, 7.5cm wingspan and a 6mm sting) and fears that it may become invasive in North America have led to the media calling them ‘murder hornets’. These are impressive insects, and may become an issue in North America, but they are not the Asian hornets that concern us.