The Encounter with the Asian Giant Hornet

Devo, of Vitriolic Monkey fame, has been encouraging me to post about the Asian giant hornet (Vespa mandarinia). This large hornet (pictured above attacking a caterpillar of unknown species) is aggressive and relatively common in Japan. Though it is easily confused with the yellow hornet (Vespa simillima), the size and thorax markings allow for identification confirmation.

Over the course of five days, I saw at least twenty Asian giant hornets just outside Nagoya, Japan. These high numbers gave me pause; initially, I second guessed the species but, after some online research, I've determined that the hornet I was seeing was indeed Vespa mandarinia.

One encounter with the species stands out. On a particularly sunny morning, as I was walking to the World Expo grounds, I elected to take a shortcut through a forest path in the Nagoya suburb of Seto. The path was landscaped and well tended; even the inset dirt steps were topped with a layer of loose gravel.

As I neared the trail's end, I noticed a young Japanese man ahead of me. He stood casually, smoking a cigarette while he contemplated the last hundred yards of the path. I smiled as I approached, nodded, said 'Konnichiwa,' and moved to pass him, but he extended his arm, blocking me. I looked at him quizzically, and, because he correctly presumed that I didn't speak Japanese, he made wild gestures uphill, toward the path's end. Making sure I continued to watch him, he then brought his arms to his sides and fluttered his hands. He resembled, I thought, a wounded chicken. "Bird?," I asked, confused (and a little amused). I opened my arms wide and slowly flapped to pantomime my guess. He shook his head vigorously. He again imitated the wounded chicken and said something in Japanese. Perhaps he was warning me of mosquitoes, I thought. (The mosquitoes were bad in Seto. Sometimes I was bitten multiple times while I slept.) "Mosquitoes?" I asked. No reply. Instead, the man extended his arm, pulled back the shirt sleeve and proceeded to use his other hand to attack his flesh repeatedly, stabbing at it like one of Hitchcock's birds. Now, even more confused by the surprise game of charades, it occurred to me that the man may simply be crazy.

I looked hard up the path, hoping that I might spot an injured goose or something that might explain the man's bizarre behavior. In fact, roughly thirty yards from where we stood, a number of large insects buzzed low over the ground. Aha! Stings, I realized with satisfaction, not bird attacks!

I'd not yet read of Vespa mandarinia, so I didn't know that their sting was described as "a hot nail through my leg" by Tokyo based entomologist, Masato Ono, or that they kill a few people in Japan each year.

I turned back to the man and nodded, making a buzzing sound and offering my own colorful interpretation of the "I'm-being-stung" routine. He smiled, happy that I finally understood him. Suddenly, though, he bolted uphill, sprinting up the dirt and wood stairs just a few feet from where the hornets busied themselves. Astonished, I watched as two hornets peeled away to pursue him. The man's white shirt allowed me to more easily track the large hornets as they chased him to the top of the hill. Once he reached the summit, the man turned back and waved. I gestured frantically, waving my arms, trying to communicate what I'd seen. I don't know if he understood my wild antics but, in any case, he spotted the hornets as they descended upon him. He yelped and ran out of my field of vision. I waited about thirty seconds before deciding that I should head back to main road to take the normal route to the Expo. After all, many hornets remained, busy near what I assumed must be their nest.

Just I started to retreat, however, I heard a shout from above. Turning around, I saw my mime friend, beaming. Apparently he'd avoided harm! I waved at him with a big smile. That smile disappeared, though, when the man motioned for me to follow his example. Nervously, I looked back at the hornets.

So the spry Japanese guy had bounded past the vespids with minimal problem. Still, the insects had pursued him. Would my six-foot, lumbering frame get me past the aggressive hornets without incident? The man motioned for a second time and yelled something that I didn't understand. Alright, I thought, unshouldering my backpack, let's do this.

I'm happy to report that my run was a success. Though taller and slower than my new Japanese friend, my legs allowed me to take two, even three steps at a time and, when you fearfully assume that huge, angry hornets are chasing you, your legs really perform. When I reached my new friend at the trail's end, he smiled broadly and laughed. No hornets had tailed me.

We turned and walked alongside one another in silence. He lit another cigarette. I declined his offer to join him with a mumbled, 'Arigato' and a gracious wave of the hand. At the next corner, we parted ways with simple nods.

I saw hornets on many occasions while in Japan, but I'm not sure that all the sightings involved Vespa mandarinia. Some of the hornets may have been Vespa simillima, as they seemed smaller and more yellow than orange. The hornet killing the caterpillar, though, and those guarding the Expo shortcut were definitely Vespa mandarinia.

Knowing what I do now, I may have hesitated more before charging uphill. A "hot nail" through my leg ain't my cup of tea, especially considering that hornets and wasps, unlike bees, can sting their target repeatedly.

When I was six or seven, I was cruelly rebuked by a dozen or more paper wasps (Polistes sp.). I remember leaning over to pick up my bucket under the hose loop and, suddenly, being in pain. By the time I realized what was happening and streaked for the house, the angry bastards were chasing me. Once safely indoors, under the care of my mother, I saw that the wasps had stung me between ten and fifteen times. While I greatly admire the Hymenoptera order (ants, wasps, and bees), I respect their territory and fear reprisal should I mistakenly encroach. I'm thankful that the hornets didn't punish me that morning in Seto..very, very thankful.

Photo credit: 2005, Hungry Hyaena