The State of Washington, together with Whatcom volunteers, has installed 900 syrup bottle traps, in the hopes of catching hornets before they attack. The sap traps were unsuccessful earlier- but it is hoped these have more success. I believe that B.C has set up some trapping on Vancouver Island, but oddly, nowhere else.
I assume that the idea of using bottle traps came from the advice of experienced Japanese entomologists and apiarists. All a good thing- they would know best.
However- the bait in that case is sweetness- carbs that are needed by adult hornets- and at some point as summer progresses- as I understand it at least- that desire lessens- and the desire for protein increases dramatically.
The hornets shift focus,
What happens? What happens is that they need protein, and lots of it, to make reproductives.. Adult hornets, astonishingly enough, can't eat solid food. Their throats are too small. Thus when they need to feed themselves only, syrup traps work. But as larva hatch and grow, they need to feed them protein, often solid food, and- this is as sci-fi as it gets- when they feed their larvae, the larvae feed them a drop of saliva. They subsist at that point primarily on larvae saliva, which has mysterious chemistry to it and allows these large wasps to fly 100 km if they need to.
At that point, they don't need syrup.
Thoraxes of course are filled with lots of meat- muscles for both the legs and the wings. Insects, unlike vertebrates, did not develop wings from legs- like bats and birds, For insects, they are a completely a new appendage, developed om their own- with their own muscles. You get legs and wing muscles are extra when you eat a thorax. Sort of a Double Mint Gum sort of thing. But even better- you get four sets of wing muscles (insects are an odd collection of multiples of twos and threes), and six sets of leg muscles. A chicken is a poor comparison. Lots to chew on. Though unfortunately, if you are an an adult wasp, you can't eat any of it. Its just for the kids.
Bees are thus a prime target when hornets need to feed queen and drone larvae. A hive is a massive candy box of thoraxes, and larvae. As are other colonies of social insects, like other wasps (like YJs- though no one know if they will succumb as as they haven't met yet). As Rusty Burlew has pointed on her website- AGHs are doing nothing more than other creatures do- just trying to get by. But come August- the need for protein is great, and a nice Langstroth hive is like a delivery from Amazon- easy to open and convenient.
And that's where the traditional hive trap on this site comes into play. It is meant to protect a hive- and to catch hornets. Catching a live hornet is so much more important the a dead one. A live one can be let go and tracked, and the parent hive destroyed. It will be a great benefit to trap a live hornet.
A bottle trap won't do that- you just get a drowned hornet.
|Trap by Howard June 2020|
But one can't wait until the last minute. It takes time to make a trap (It takes me an hour- but I think I can get this down to 30 minutes), and it takes time to get a hive used to it. You can't just stick one on your hive they day the hornets show up. Your bees need a week- at least- to learn how to get in and out without exposing themselves.
It's not the only way to protect hives- screens (of many kinds) and sticky boards are options too- and Matsuura in his paper suggests 10 screen preventers to each hive trap- but the hive trap is essential.
In any case- it's what I'd do if I were there- though I'm not- and as I have stated elsewhere, I've never seen or trapped a giant hornet, so can't speak from experience. All I can really say is that these are used in Japan, and sold by Japanese beekeeping vendors, and has been used at least since the 1950s. So has some track record at least.
Good luck Northern beekeepers!