The “Murder Hornets” AKA Asian Giant Hornet

Well. Thanks New York Times. 🙄🙄

Hai. I’m Nancy – I was supposed to write my “Re-introduction” this week because of our hiatus. However …

Now that every entomologist ever needs to clean up this puked up fur-ball of a mess that is the non issue of the not so murderous murder hornet, I have written you this beautiful piece of literature instead of my reintroduction.

The gist of all this is, the Asian Giant Hornet is NOT murderous, and it’s not a threat to you in the US.

But here’s the long of it.

If you want to watch the full interview I did with Jon Perry from Stated Clearly you can watch it here! It was a live video so thanks to everyone who tuned in! If you’d rather read basically all the same points, continue below after the read more tab.

Thanks Stated Clearly!

1) Escaped but not established and definitely not invasive.
Most likely eradicated.

A large orange and black hornet.
A male Asian Giant Hornet
Photo Credit: Yasunori Koide CC BY SA 4.0

A short note on invasive species:
To be invasive you need to be two things:
a. Non-native to the ecosystem
b. A threat or potential threat to human health, the economy or the environment.

Species become invasive because there are no natural enemies (predators / disease) to keep them in check. Due to this, they tend to out-compete native species and proliferate at an alarming rate. Not all species become invasive. This is called the Tens Rule. Out of all non-native species, only 1 out of 10 are considered escaped and found in the wild. Of those, 1 out of 10 become established – which means they can function and reproduce within the new environment. And of that! 1 of 10 become invasive. If you’re interested in learning more about invasives – check out my live video here.

Now back to the regularly scheduled program:

One colony of Asian Giant Hornets (Vespa mandarinia) was found near Nanaimo, British Colombia (outside Vancouver) in September 2019. So, 8 months ago.  The nest was destroyed using carbon dioxide (C02) which is minimally damaging to the environment. Since then, one worker hornet was found in the northwest corner of Washington state in December; just over the border in Blaine, Washington. It wasn’t very far from where the original colony was discovered. In fact, just over 50 miles away. The Asian Giant Hornet is a eusocial insect meaning that the colony’s workers are sterile. The one worker was found dead, and even if it wasn’t, couldn’t reproduce or start a new colony.

Map showing the US and southern Canada with two dots in the upper northwest. One in British Colombia and the other just past the Canadian border in Washington showing the locations of the two sightings.
The location of where the original colony was found and the one dead worker.
The distance between the two is only about 54 miles.

That’s it so far.
Yup.
Just that 1 colony.
Just that 1 worker.
So they’ve escaped … but hardly established and are nowhere near invasive.


In fact, a researcher, Doug Yanega who worked on the project had this to say.

I was one of the authorities brought in to consult on this case, and to my knowledge there have not been any sightings in 2020 that would suggest the eradication attempt was unsuccessful.

2) What Even Are Hornets?

Hornets are in the genus Vespa within the family Vespidae, within the order Hymenoptera. But really the difference between wasps and hornets is hand wavy at best especially when it comes to common names. Basically people use the word “Hornet” to effectively say “Giant, scary, terrifying, wasp on steroids, yellow, flying black, stripy, thing.”

Vespa (hornets), Polistes (paper wasps), Vespula (yellow jackets) and Dolichovespula are the genera of social wasps in the US. The European hornet (Vespa crabro) is the only non-native hornet currently established in the US with its range between the eastern and central United States.

A large yellow and black hornet hanging upside down from a a white flower and eating a honey bee.
A European hornet (Vespa crabro) the only established non-native hornet in the US.
Photo Credit: Richard Bartz CC BY SA 2.5

3) The Asian Hornets are Giant … but not THAT Giant …

For the record, they are LARGE wasps. Reaching 1.5 inches (4 centimeters) they are the largest *social* stinging insect. But not *that* large in comparison to other insects. Some stick insects measure in at a foot long (30 centimeters), and many big beetles measure up at 3in body length and weigh as much as a small rat (half a pound). They’re not even the biggest wasp (contradictory to almost every other media site…) which is Pepsis heros. This tarantula hawk has the most painful insect sting and measures up to 4 inches (10 cm).

A long haired woman with purple glasses. Her hand is outstretched and in it is a large, black,  horned beetle taking up her entire hand.
This beetle is Megasoma acteon.
One of the largest beetles coming in at almost 3 inches and weighing about half a pound.

The Asian Giant Hornet measures in 1.5 inches and weighs about 3 grams.  Most of those sensationalized photos are pictures in kids’ hands or a perspective trick, holding the wasp close to the camera.  But, because they are the largest *social* stinging insect, they do have a large venom load. They’re just packin’ more heat because they can fit more of it inside them.

A large orange and black hornet sitting on the edge of someone's f showing off its relative size.
Here’s a pretty neutral perspective photo taken showing the side of the Asian Giant Hornet.
Thanks Kurt Bell for showing them off as they are.

4) They’re Not Murderous … At Least Not to You

In 2013, these hornets also got bad press for “invading” China. Headlines, not unlike the ones we’re seeing now in the US, came to light.
Killer Hornets Rampage Through China
Deadly Hornets Kill 42 In China and Injure 1,500 Others
And so on …

So their hype has always been a thing. What they don’t tell you is that honey bees kill more people. About 100 people in the US to be specific. 40ish people die in the US per year due to dogs. Deer cause about 200 human deaths per year and are even more costly in property damage. And while we’re spouting out dangerous animal facts, they’re not nearly as “murderous” as other  insects like mosquitoes. According to WHO and UNICEF, mosquitoes transmitting malaria killed about 3,000 children per day in 2003. And in 2019 those stats were updated to suggest that every 2 minutes a child dies from malaria. So where are all the “Murderous Malaria Mosquitoes” articles?

A mosquito on human skin so engorged with blood from feeding that a blood droplet is escaping its abdomen.
Murderous Mosquito.
Anopheles mosquitoes transmit malaria
Photo Credit: Jim Gathany, Public Domain

But back to the hornets. Asian Giant Hornets in their native range kill upwards of 40-50 people each year and significantly fewer in Japan.

On average, it takes 59 stings from these hornets to kill an adult. After 28 stings, you should definitely go to the emergency room, and after 10 you should seek medical assistance.

On a side note, healthy adults can usually withstand around 1,000 honey bee (Apis mellifera) stings. Of course, if you’re allergic – which is when most deaths actually occur, just one sting from either of these animals is enough to send you into anaphylactic shock. Allergic reactions are what cause most bee and wasp related deaths.

5) Then Who Are The “Murder Hornets” Murderous To?

These “murderous” hornets are only murderous to their prey.
Bees. And specifically, bee larvae.

Weighing a lot (for a wasp), having a lot of venom, and powerful jaws, they make quick work of what gets in their way. They tend to eat other insects, but they do really like bees. Especially bee larvae. Especially honey bee larvae.

Because Japanese Honey Bees (Apis cerana japonica) and these Asian Hornets share a range together, native to Asia honey bees can fight off the attackers. When the first few scouting hornets enter the scene, the Japanese Honey Bees literally swarm the invading hornet and grab onto any part of it they can: legs, antennae, wings. They then make a giant ball of fury around the hornet with their bodies and maintain the invader at the center.

The honey bees can raise the bee body ball’s heat to 47⁰C (127⁰F) and a CO2 level of 3.6%, killing the hornet inside. The bees can withstand temperatures up to 50⁰C and escape unscathed.  

A ball of many honey bees on the ground.
A defensive bee ball around a hornet.
Photo Credit: Takahashi CC BY SA 3.0

Apis mellifera or our European Honey Bee – the one that we have in the States, has no natural defenses against this hornet since their ranges do not overlap. Just 10 hornets can make quick work of a hive of thousands of European Honey Bees. Wasps in the native range of the Asian Giant Hornet will sometimes just abandon their nest since they don’t have effective defense mechanisms.

6) So it’s the beekeepers who are worried

Therefore, much of the hubbub  is made by beekeepers. European honey bees do not belong in the Americas! We have them to mainly pollinate European crops that we also grow here. Almonds, for example. These Asian Hornets aren’t murderous to humans … they’re murderous to bees making quick work of entire hives. And we rely on those bees to produce much of our produce.

European honey bees are domesticated and unnatural in the environment. Akin to flying pigs, or cows – honey bees have been kept and maintained by humans as far back as the ancient Egyptians to 3,500 BC! And that’s just our earliest written record! Honey bees flying around in our ecosystems looks just about as natural as a milk cow standing in the middle of giant Sequoyas. That is to say … not.

A cow sitting on the beach looking wistfully at the ocean next to a colored umbrella.
If you think this cow on a beach looks weird, then a European Honey Bee anywhere in the US
should also look equally as weird.

Photo: Veronica VanZeipel

That isn’t to say honey bees don’t have their fair share of natural enemies. Robber flies, mites, fungus, viruses. This is actually *good* because it ensures that escaped honey bees don’t overwhelm native North American bees and pollinators, although there is evidence they already do that. Point being, predators and disease keep species in check and prevent them from causing catastrophic harm.  Especially if those species are non native.

7) I want to help!

That’s great!! Thank you!

First and foremost, folks who aren’t scientists are invaluable when it comes to tracking new invasions. We owe a lot to the public’s help when it comes to tracking things like the Spotted Lanternfly. (Maybe if we change its name to the Spotted Slaughterfly it would get the media press and coverage it deserves cuz it’s actually a problem rapidly spreading through the north eastern US).


That being said, when we report these kinds of findings, we need to be very specific about the folks who need to be on the lookout. If you live within 50 miles of Blaine, Washington please keep an eye out. Insect invasions move slowly, and people in, say, Iowa aren’t gonna find one of these gals.

Trapping should only be done by professionals in the Blaine, Washington area.

Trapping in other areas is detrimental to native species that are early emergers in the spring. Many people are also just killing “yellow stripy things” willy nilly. This is killing off many native species including bumble bee queens which are some of the first active bees and pollinators in the spring time.

A picture of two honey bees queens with a caption that says "DON'T KILL ME! I'M NOT AN ASIAN GIANT HORNET! Bumblebees are hairy and gentle beneficial insects. Please DO NOT kill bumblebees if you see them. Learn more at agr.wa.gov/hornets
A message from the Washington State Department of Agriculture. They had this to day.
~~~

We’ve received a lot of reports of suspected Asian giant hornets lately – which turn out to be bumblebees that well-meaning people have killed thinking they were AGH.

Bumblebees are “hairy” unlike the Asian giant hornet. They are gentle and beneficial pollinators – please don’t kill them!

Learn more about Asian giant hornets at agr.wa.gov/hornets.

Everything from moths, to other bees and wasps, to beetles, have been mistaken and killed. An unfortunate victim is the Cicada Killer (Sphecius speciosus) -a docile wasp that just wants to feed cicadas to its babies.  If you’re not sure what the insect you’re looking at is, take a picture and let it live. Send that photo to entomologists or your local universities’ extension agent for an ID. Once confirmed with a GPS location, professionals can better assess and manage the situation.

Two large yellow and black wasps resting peacefully on a woman's hand.
Please don’t kill these. These are naive to the US Cicada Killers. Very docile wasps that really just don’t want anything to do with you. They eat cicadas. Not bees.

Photo Credit: Anita Gould CC BY NC 2.0

TL;DR

Basically, the “Murder Hornet” or the Asian Giant Hornet (Vespa mandrinia) is not considered to be established in North America. The only people who should be looking and trapping for it are professionals around the Blaine, Washington area. They’re not even really a health risk. The reason people are worried about them is because they make short work of European honey bees and there is the tiniest of chance that they may be in one small restricted area of the country.

The head of an Asian Giant Hornet. Large orange insect head with big black eyes.
Asian Giant Hornet Head
Photo Credit: Gary Alpert CC BY 2.5

References

  1. Embry P. 2020. Just How Dangerous is the Murder Hornet? Scientific American Accessed 11 May 2020
  2. Schmidt J. 2016. The Sting of the Wild. John Hopkins University Press United States of America
  3. Sheppard WS and Meixner MD. 2003. Apis mellifera pomonella, a new honey bee subspecies from Central Asia. Apidologie 34: 367-375
  4. Tomlinson S. 2020. To the Editor of The New York Times. Facebook Post. Accessed 11 May 2020.
  5. West Virgina University. 2020. It’s Time to Kill The Murder Hornet Headlines. Newswise Accessed 11 May 2020
  6. Whitfield CW, Behura SK, Berlocher S, Clark AG, Johnston JS, Sheppard WS, Smith DR, Suarez AV, Weaver D, Tsutsui ND. 2007. Thrice out of Africa: Ancient and recent expansion of the honey bee Apis mellifera. Science Reports 314 (5799): 642-645
  7. Yanega D. 2020. Media Circus. Facebook Post. Accessed 11 May 2020
  8. Youichi Yanagawa. 2007. Cutaneous hemorrhage or necrosis findings after Vespa mandarinia (wasp) stings may predict the occurrence of multiple organ injury: A case report and review of literature. Clinical Toxicology 45: 803-807

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2 Responses to The “Murder Hornets” AKA Asian Giant Hornet

  1. Christine says:

    Thanks for writing this. My impression — granted, I come at it from the perspective of being an invasive species biologist myself — is that people are not really as anxious about the Asian giant hornet as the headlines and social media reblogs suggest. Everyone is stuck at home, fighting anxiety over an invasion by something they CAN’T see, and all the COVID-19 memes that helped us shake off the tension two months ago are growing stale and a little macabre now. I think there’s a lot of relief in being able to make jokes about something as benignly scary as a “murder hornet.” It’s campy B-grade horror at a safe distance, with the useful side effect of generating a new round of memes that we haven’t seen before, and that haven’t taken on the bitter tang of political divide.

    I DO hope it doesn’t lead people to go on a rampage against native hymenopterans. I hadn’t thought of that terrible possibility, and I’m definitely going to add “DO NOT DO THAT” to my repertoire of PSAs. But generally, I don’t mind the fuss about the hornets. A lot of people ask me about them (I am also a beekeeper, which makes people assume I am an expert on all stingy flying things) and it’s been a good opportunity to educate. And meanwhile… I admit, the memes have given me a badly-needed laugh or two right now, too.

    Liked by 1 person

  2. Gene Pozniak says:

    The media has focused on the supposed “fact” that Asian giant hornets invade honeybee hives in order to “eat the thoraxes of the bees for their high muscle protein content, flying away with bee thorax ‘meatballs’.” I know this is at least partially false, as every video I’ve seen of giant hornets attacking hives has shown them focusing on obtaining the soft, tender bee larva and completely ignoring the dead bees.
    Can you tell us if they do eat dead bees and if so which parts they eat? I didn’t think they were cabable of ingesting the tough muscle tissue of the thorax.

    Liked by 1 person

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