WSU scientists enlist citizens in hunt for Asian giant hornet | Hacker News Reader

WSU scientists enlist citizens in hunt for Asian giant hornet

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51 pointsspking32 comments

Japanese honey bees have a remarkable defense strategy against these things. From the Wikipedia page for Asian giant hornet [1]:

> As the hornet enters, a mob of hundreds of bees surrounds it in a ball, completely covering it and preventing it from reacting effectively. The bees violently vibrate their flight muscles in much the same way as they do to heat the hive in cold conditions. This raises the temperature in the ball to the critical temperature of 46 °C (115 °F). In addition, the exertions of the honeybees raise the level of carbon dioxide (CO2) in the ball. At that concentration of CO2, they can tolerate up to 50 °C (122 °F), but the hornet cannot survive the combination of high temperature and high carbon dioxide level. Some bees do die along with the intruder, much as happens when they attack other intruders with their stings, but by killing the hornet scout, they prevent it from summoning reinforcements that would wipe out the entire colony.

[1] https://en.m.wikipedia.org/wiki/Asian_giant_hornet

European honey bees, such as those in the US, lack this adaptation, which is a big part of why it's important to prevent V. mandarinia colonizing the US.

I believe V. mandarinia are also significantly more dangerous to humans. Nearly as many people are killed by them in Japan every year (30-40 according to wikipedia) as are killed by hornets, wasps and bees combined in the US (62 per year on average: https://www.cdc.gov/mmwr/volumes/68/wr/mm6829a5.htm) Bear in mind those figures aren't per-capita.

Their size gives them a larger venom dose per sting, and I gather they're more inclined to sting repeatedly than other wasps. I think I remember reading their venom is actually more toxic by volume than the usual as well, but not so sure there. Either way, you're quite right.

I'm pretty cavalier about risking stings for the most part, because I'm familiar enough with bees and wasps to know how to avoid making them feel threatened, and I'm not allergic in any case - and taking a calculated risk, for the chance at an excellent photo, is in my estimation worth it. Even so, I think I'd be very hesitant to approach a V. mandarinia individual unless I was very certain her nest was nowhere nearby. Maybe not even then. Calculated risk is one thing, but with these I'm not at all sure the math works out.

All that aside, I'm more worried about the risk to bees than that to humans, who are only ever attacked incidentally by wasps in any case. Our primary pollinators are already under threat enough without having to face the hymenopterans' answer to a Terminator.

They should enlist dragonflies. A few years ago I was chased by this type of hornet in rural Japan and was saved by a dragonfly that intercepted it in a dramatic takedown.

Does the dragonfly only attack hornets or would they also attack the bees?

Not sure I would've survived the heart attack to see the takedown. These hornets are the stuff of my nightmares.

Now this makes me wonder what kind of wasp I’ve seen attacking bees in my garden in Sweden.

A very large wasp, I thought 2” in length, with the classic black and yellow stripes. I had assumed it was solitary. I’ve seen them hovering near the entrance of a wild hive and swooping on bees as they land and start to crawl in. The bee and wasp then tumble down to the ground, and there’s a struggle. Then the bee is released, and flies back to the hive. The wasp returns to hover by the entrance, awaiting its next victim.

These massive wasps will reappear this summer, as usual. I will have to try and identify them better. Anyone have any ideas?

Here in Austria, I've seen similar wasps, and as my house is surrounded by flowering fruit trees, I've had to deal with trapped-at-the-window individuals a number of times (bees and butterflies too, which is a wonderful brief visit until I free them to open air). I'm not entirely sure they are Asian Giant wasps, but they sure are big and nasty and angry .. I'm fairly sure they are European hornets, though:

https://en.wikipedia.org/wiki/European_hornet

Have you seen these giant wasps in your garden attacking and then releasing the bee? I’ve been assuming mine are a kind of solitary parasitic wasp. I think I’ve actually seen them stabbing the bees with their tails before releasing them. But they definitely look like those hornets you linked to! Just the activity seems wrong.

From the Wikipedia article:

> However, they are also known to "hawk" in midair for honeybees near their hive, which they then take down and consume.

https://en.wikipedia.org/wiki/European_hornet#Problems_assoc...

I haven't seen them attacking anything but my apricots. ;)

Probably a european hornet? They are the biggest I know of here, and are yellow and black.

They are harmless to humans and protected.

Vespa crabro just are too busy with they own bussiness, and are relatively peaceful, but not harmless to humans. Terrific gentle giants.

The quickest way to see their "not harmless" side is to kill one. As with many colony wasp species, other individuals will smell volatiles released by the corpse, and respond by seeking out whatever killed their sister in order to strongly discourage any further such liberties.

So, best leave them well alone. (Unless you're me, and willing to risk a sting in order to get macro shots, although it's not all that much of a risk as long as I'm not near the nest. Never have found any hornets yet, though, sad to say, not even D. maculata.)

I read some time in the last few years that Asian giant hornets were migrating into Europe. It's an easier migratory route than across the Pacific. I wonder whether the spread of apiculture has produced a food bridge they can exploit.

Here's the first hit I turned up on Google: https://www.thesun.ie/tech/5302630/giant-asian-hornet-invade...

Could it have been a Mammoth Wasp?[1] I've seen one in the Netherlands 2 years ago. Very distinctive pattern on the abdomen.

1: https://en.wikipedia.org/wiki/Mammoth_wasp

Would a mammoth wasp attack a bee? Scoliids are parasitoids, and this one is described as having a life habit typical of the family. Typically the adults feed only on nectar, unlike the more predatory vespids.

The markings feel familiar. Of course I am not being objective and need to actually get one in front of me to check when they are in season.

Yes! Now I definitely have to check the next one I see or find! It really could be this monster! Will try to get footage of them overpowering then releasing bees.

Only problem is how to share my findings in a month or two when they are active!?

In swedish they're called "bålgeting". They look and sound scary because of their size but are actually non-aggressive and mostly helpful to humans as they prey on regular wasps and aren't interested in our food and drink like regular wasps are. Didn't know they took bees but I guess that makes sense.

Because hornet is much bigger then bees

Is it possible to build a cover outside of the hive with holes that only bees can pass through?

Welp, guess I'm never going to Washington

I'm stuck here in WA... with THEM.

I’ve never seen one of those (in NC) but I have seen the enormous Cicada Killer Wasp which is relatively harmless

https://en.m.wikipedia.org/wiki/Sphecius_speciosus

We have tons of those in Central Texas! But they're not aggressive at all, if a little curious. Definitely huge. I've also seen a few tarantula hawks, which look very evil.

I can’t seem to make my brain connect the “theyre harmless” knowledge with my eyes telling it “omg that’s a flailing ball of gigantic bees tumbling right for me!”

Entirely harmless. They never sting unprovoked, but they do seem very intimidating with their size and their inquisitive demeanor.

On the one hand it's obvious why they need to be eradicated given how disruptive they are to the ecosystem, but on the other hand it makes me a little sad, they're beautiful animals.

Scientists shouldn't encourage people to deal with a potentially lethal animal, and by the way, how a chinese giant hornet ended being introduced in Washington? Those things are unmistakable. Was nobody in charge?

Is nature boycott everywhere you look...

They're encouraging people to identify and report them so they can be eradicated.

> “Don’t try to take them out yourself if you see them,” he said. “If you get into them, run away, then call us!“

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