This one is the Asian Hornet, or Frelon Asiatique, to give it it's French name.
So, this week we didn't open up the hives, but had a lecture on Asian Hornets.
It's thought they arrived in France in 2004/5, via a cargo ship from China. The pottery that hosted the stow-away hornets was delivered to 3 regions in France : Gironde, Lot & Garonne, and Dordogne, and from there they have spread across the country at a rate of 100km a year ! Now - nearly ten years on, there is only Corsica, and the Alsace region, next to Germany, that remains free of them.
Female hornets mate in the autumn, then usually survive winter alone, in crevices in buildings or tree trunks. In the spring they emerge to feed on the first flowers, then build small starter nests. These will reach about the size of an orange. Inside, they build cells, lay eggs and feed the larvae - hornets don't make any wax, unlike bees, their nests are constructed of a paper/cardboard like vegetable pulp. Tough life for the queen hornet in spring, major multi-tasking: until the first eggs she lays hatch out to become her workers, she's on her own.
Which makes it the best time to wipe them out, when one individual is all that is keepng the starter nest going.
But... normally, if the female doesn't fall foul of a hornet trap, the first workers will hatch, then depending on the site chosen for the starter nest, they will either move and create a much bigger nest in a tree top for example, or extend the starter nest if there's room. The queen then concentrates on laying eggs, and the rapidly growing work force hunt for food, and extend the nest, until by the end of summer it can be over a metre in diameter. However, for some reason the nests are not used again the next year - perhaps the papier maché construction isn't strong enough, or water tight over winter, anyway the whole thing starts again the following year, with the constructions of new nests.
Hornets don't store any food in their nests - they are predators, and their chosen food is protein. They hunt bees, and once they catch one, they will land on a nearby ledge or branch, pull off the head, legs and abdomen, and carry the protein-rich thorax section back to their nest, to share. They are also partial to fish, and are a pest at markets where often they can be a nuisance on fish stalls, landing on the fish for sale, and have even been known to fly off with small seafood like shrimps or prawns !
Again, unlike bees, hornets can sting repeatedly, and tend to gang together to attack when they perceive a threat - such as loud noises, machinery, or somebody shaking their tree, kicking a football at the nest etc. Hornet stings have been a contributory factor in over 20 deaths in Gironde alone ( just 1 "county"!) over the last few years. So all in all, I feel justified in joining the crusade to reduce their numbers.
To date, I still haven't caught any hornets in the trap in our garden, though I keep renewing the "bait" - a mix of beer, wine and sweet syrup, each week. Perhaps this is a good sign, that no female hornets looking for their next move have wandered into our garden? Apparently Raymond, the lecturer this week, has already caught 11 this year.
We all filed outside to see a demonstration of how hornets nests are destroyed, should you need to call in an expert, or "Perchiste" . Not even sure that's how its written, but they use a long pole, with a hollow spike attached to the top, which has holes pierced in the side of the tube below the point. A rubber tube is attached to the bottom of the rigid metal tube spike, which runs all down the side of the pole, to a cylinder of sulpher dioixide. The perchiste gets as close as he thinks safe to the nest, using a ladder or cherry picker thing, then prods the point of his pole into the nest, and opens up the sulpher dioxide gas. I think the use of sulpher dioxide is regulated, there are 30 official Perchistes in Gironde. I'm guessing the name is due to the pole, not that they often have to "perch" half way up a tree!
Once the hornets have started to fall dead on the ground, they are burned, and the nest is burned too, to kill off any eggs and larvae that would otherwise survive the gas.
Apparently the tricky bit is knowing how far to poke the point in, as if it goes too far, the holes can get sealed with larvae gunk, so the gas can't enter the nest, and likewise not far enough, or missing the nest altogethor, will only annoy the hornets, not kill them !
It was cold (11°) and drizzling, but we had one final task, to check the Varroe tests we had left beneath the hives last week - cardboard dosed with oïl and anti Varroe product (it sounds like Tactique ?) - one of the team kitted up to retreive the strips of cardboard. All was OK, no trace of Varroe mites.