Just noticed this as I and others in France have had these for a while. Basically they pin the bees in the hive which is the worst part, predation accounts for the rest. If the bees are pinned down the queen stops laying (like a dearth) and if they take a lot of bees then the hive has to work hard to make up the losses.
They are alrady in the UK, just, and will advance
Vespa Velutina Most likely source would be bales of stuff especially right now as the queens will have just gone into hibernation so may have gone into timber etc outside. When this is moved elsewhere if it is used before spring they will probably die when exposed, if left they will emerge.
They reckon up to (as a max) 500 queens / nest but only 10% make it to establish, they fight amongst themselves for territory and are predated. No stopping them really, they are starting on colder countries and are adapting. They predate 30% bees in the countryside 60% in cities, idea is other prey in the countryside.
I did a group with loads of info on them, please don't join unless you have actual experience of them as we are only looking for practical experience if you have found something that works for you.
asianhornet-beehiveprotection groups.io Group
Post general ideas on this forum.
Muzzles, mesh, wire, tube etc stop them being pinned down, which is very important, and reduce predation but can't stop it. They will be there but will take a while to spread, spoiler alert they like built up areas.
Some video of how they behave at muzzles, these need some refinement, and you can see the bees are not bothered by them, till caught. I had just 2-3 AH/hr so not a problem, a friend had lots and lost 4 of 7 hives.
AH muzzles