A venomous Asian hornet has been spotted in Hampshire just month after experts predicted a plague of the pests.
The hornet, also referred to as yellow-legged owing to legs that transition from brown to yellow at the ends, are capable of destroying the country’s bee population.
As with bees and wasps, the Asian hornet has a painful sting. The sting of an Asian hornet is no more harmful than that of a bee or wasp although if a person is allergic to bee or wasp stings they are also likely to react to the sting of an Asian hornet.
However Asian hornets may act more aggressively than most other indigenous bee and wasp species if their nest is threatened so it is important not to deliberately provoke them. When foraging for food away from the nest the Asian hornet is no more aggressive than a normal wasp.
The first known sighting of an Asian hornet (Vespa velutina) in Guernsey was in March 2017. Asian hornets have spread through Europe after arriving in Southern France in a consignment of pottery in 2004.
The Asian hornet is a non-native invasive species and an aggressive predator of many types of insect but on average 30% of its diet is made up of honeybees. The Asian hornet is therefore a major threat to our biodiversity, pollinating insects, and beekeeping activities.
“Spring Queening” phase
The Asian Hornet Strategy aims to keep the population of Asian hornets as low as possible. The first phase is a comprehensive island wide programme to trap queen Asian hornets as they emerge from hibernation, or travel across the water from France, in the spring – so called the “Spring Queening”.
Early spring (April-May) is the time when Asian hornet queens emerge from hibernation and start to build their nests. These early nests are made exclusively by the queen and are sometimes called ‘primary nests’ as they are much smaller than the huge secondary nests made by worker hornets in the summer/autumn months.
The primary nest starts off golf ball sized and soon grows to about the size of a small orange (2½ inches / 6 centimetres in diameter). They are pale brown in colour and made of papier mache which the queen makes by chewing wood and mixing it with water.
If left undetected the solitary queen hornet continues laying eggs and feeding the larvae until she has raised a small brood of worker hornets, typically by the end of June. After this time the queen and her workers will normally relocate to build the large main nest, often high up in a tree.
“Track Don’t Trample” phase
The second phase of the Asian Hornet Strategy starts once the queen Asian hornets have left their primary nests along with their small brood of worker hornets to build the large main nest in a new location.
These large nests expand rapidly during August – September and can hold up to 5,000 hornets. If left uncontrolled Asian hornets will present an increased risk to the public as well as causing significant harm to our native insect populations, such as bees, as they are voracious predators.
To locate these main nests, members of the public are encouraged to “Track Don’t Trample”. During this phase, if you think you have spotted an Asian hornet, take a photograph if possible and take note of the direction the hornet travels.