Photo right - An Asian Hornet nest in a shrub close to the ground.
Risk to humans from this species are minimal except when and if they consider their nest to be under threat, otherwise they are more timid than the European Hornet and their sting is no worse than that from an ordinary wasp.
They are only out during daylight hours unlike the European Hornet that will also fly at night.
As with all the social wasps (common Wasps, Hornets and Polistes), the colonies of the Asian Hornet live only one year and it is only fertilised queens survive the winter in hibernation.
Photo right shows Asian Hornets and Honey bees feeding together on wax and honey in late October. At this time the Asian hornets will normally not kill the bees because they should have stopped producing eggs and there would be no larvae to feed, although they will rob weak bee colonies of their honey stores given the opportunity. Hornet protection grills can be fitted to hives if required.
Although the European Hornet will attack and kill the odd honey bee in small numbers as a food source for their larvae it does not present a problem, however the situation is supposed to be far worse with the Asian Hornet and can possibly lead to the destruction of the entire colony. The Asian Hornets will station themselves hovering at about 30cm from the entrance to the honey bee colony where they pounce on returning bees that are carrying pollen, fall to the ground with them, cut of the head with their mandibles and transport them to a tree. Here they remove the wings and legs before making a little “meat ball” that they transport back to their nest to feed their own larvae. Having found a colony, often a bee hive, they will sometimes arrive in numbers to take an easy food source one after another. The consequences for the bee colony can allegedly be catastrophic if the flow of pollen into the hive is severely disrupted. Over time it could result in the death of some or all of the larvae and the queen will either stop or reduce her egg production. This will lead to the decline of the colony, aging bees will die with few or no replacements to take their place. At best the colony will be vulnerable to disease due to the dead larvae and the overall weakness of the colony will lead to robbing. The colony will have little hope of over wintering.
The nest is built using “paper mâché” made from chewed tree and plant material. The initial nest is constructed by an overwintered Queen under cover in an open fronted barn, shed or similar structure. It is composed of several wafers of cells surrounded by a double skinned envelope of broad reinforced paper scales, striated with beige and brown. Once the initial brood have been raised the colony will normally move and create the main nest. Unlike the European Hornet where the entrance is on or near the bottom, the entrances are on the sides, (see photo). Another difference is that the European hornet usually makes its nest in cavities, whereas the Asian Hornet makes a suspended nest, usually in a tree but sometimes in a large open roof space, although there is now increasing evidence that the main nest may be constructed as low as 50cm from the ground in a bush or other scrubby growth. This is easy to see; it is spherical or oval and can be as much as 1 metre in height, 80cm in diameter and generally between 4 and 15 metres from the ground. It is rare for it to use a hollow in a tree or cavity in the ground. Unfortunately the nest is sometimes hidden by the trees foliage and as its comings and goings are more discrete than the European hornet their presence isn’t always noticed until the leaves begin to fall in early autumn.
Slightly smaller than the European Hornet, with queens up to 30mm, and workers up to 25mm, they are easily recognised by their appearance and difficult to confuse with any other species. The thorax is a velvety black / dark brown with brown abdominal segments bordered with a fine yellowy orange band. Only the 4th segment is almost entirely a yellowy orange. The legs are brown with yellow ends and the head is black with an orange yellow face.
First observed in 2005 the Asian Hornet is thought to have arrived in France from China in 2004, in a container of pottery passing through the port of Bordeaux. Since that date its spread throughout the neighboring regions has been rapid and often, in the initial stages, follows rivers and other watercourses. In fact it will never be found far from a source of water even if that is only a small pond. As of 2011 there are reports of them being observed in Belgium and they are to be found in strong pockets in the north of France, the expansion is relentless although the poor weather in the first 6 months of 2013 seems to have caused them some problems.
Vespa velutina nigrithorax
Photo above - Asian Hornet with captured honey bee.
Photo right - Queen Asian Hornet making initial nest.
Photos above and right of Asian Hornet nests high in trees in France. Colours of nests depends on the the trees used for the materials.
Photos above and right of Asian Hornets in Vienne (86), France