10:30 p.m. October 8, 2013

Bee For Vendetta

In the past three months, dozens of people in China’s Shaanxi province have been killed by swarms of giant, venomous hornets. It is the stuff of nightmares. As Chinese news agency Xinhua reports, the hornets, which are around two inches long and horrifically proportional, have killed forty-two people and injured over 1,600; 206 patients are currently hospitalized.

Coverage of the attacks in the Guardian includes a video featuring several survivors; their skin is covered in pits of decay, small craters where the stingers deposited their venom. Affected flesh appears dotted with tiny islands of casu marzu, though - thankfully? - without the maggots. Actually, it kind of looks like necrotizing chicken pox. One patient recounts saving himself by putting a basket over his head.

The culprit? The Asian giant hornet. With venom so toxic that it can dissolve flesh, flooding the bloodstream with debris, leaving victims of mass envenomations on dialysis for months, one thing is patently clear: it’s time for a new installment of Nature Wants To Kill You. Let us turn our focus today to Vespa mandarinia.

The world’s largest hornet, about the size of an adult human thumb, V. mandarinia is makes its home in eastern and southeastern Asia. With yellow and black stripes and menacing dark orange mandibles, adults feature a set of compound eyes and three simple eyes, as well as a black tooth that can be used for digging. Their stingers are about a quarter of inch long and smooth, unlike most bees, whose barbed stingers are fatally ripped from their bodies when they pull away from their target. The lack of serration means that angry lady hornets can sting, pull out, and re-sting as they please. And it is definitely ladies-only: like all other hymenopterans - wasps, bees, and ants - the males lack the stinger, as it is a modified ovipositor.

And you can bet your ass that the venom squirting through that stinger is fucking brutal. The overall reaction to hornet venoms in general is complicated, as the resulting physiological response is due not to a pure substance, but to a dangerous cocktail of substances ranging from pain-causing peptides to neurotoxins, from hydrolases that break chemical bonds to biologically active amines like adrenaline, histamine, and serotonin.

When an Asian giant hornet stings a human, they introduce venom so powerful, it can virtually dissolve flesh. By breaking chemical bonds and bursting cells, they unleash a torrent of cellular debris. The wreckage of destroyed blood and muscle cells enters the bloodstream, to circulate until the body’s filtering system - the kidneys - can remove the waste. Patients piss streams of black coffee and blood, the amount of foreign proteins (and possibly nephrotoxins) causing the kidneys to fail.

V. mandarinia venom also features mastoparan, a cytolytic peptide that chews up cell membranes and other lipophilic substances, and mandaratoxin, a presynaptic neurotoxin. Before a neuron fires, it sends an electric impulse down the axon; mandaratoxin blocks the sodium channel that makes this possible, rendering neurons able to receive information, but unable to transmit the message further. Mute, but not deaf.

Mandaratoxin can be fatal all on its own in sufficient doses.

Of course, Asian giant hornet venom contains far more than two components; a complicated slurry of bioactive compounds gets unloaded every sting. And while a few stings won’t kill or greatly harm a healthy, non-allergic adult, the sheer size of the hornets and their corresponding venom payload combined with their propensity to swarm attackers puts V. mandarinia squarely on the Nature Death Squad.

I suppose you’d like to know how to avoid them.

Asian giant hornets make their nests underground, digging burrows or moving into cavities excavated by rodent ground dwellers. Sometimes they move into urban structures or near rotted pine roots. And, as you might assume, life inside their nests is busy. They are "eusocial," meaning that they exhibit the highest level of animal sociality: cooperative care of young, overlapping adult generations, and a division of labor by groups that reproduce and those that (usually) do not. It’s their eusocial nature that makes them so fearsome; unlike their more solitary brethren, when they sense that this nest is under threat, they swarm. Mass envenomations, the kind that land people in the hospital - or worse - are the result of thousands of hornets, rushing to ardently defend their home.

But let’s talk about something less panic-inducing. Let’s talk about sex. Unlike other hornets, V. mandarinia do not do their fucking underground, rather, they bring that shit out into the light of day. In the crisp days of autumn, those exhibitionist queens leave the nest; once she’s out, a male will grab her in mid-air. The two fall to earth, where they copulate on the ground for less than a minute. It’s all terribly dramatic and exposed.

Soon after, a queen will leave in search of a place to over-winter. She stores the sperm internally until spring, at which point, fertilization occurs and she begins her new colony. After laying up to forty eggs, she’ll tend to this initial clutch herself, providing care for her first generation of workers. Later in the season, she’ll lay thousands and thousands of eggs, to prepare for next season: eggs that have been fertilized will become queens; unfertilized eggs will become workers, dividing the labor to cover care of young, feeding the queen and larvae, guarding the hive, hunting for food, and nest building and repair.

The sperm-storage is cool, but their fucking dietary set-up is incredible. Adults, who are relentless hunters of beetles, mantids, hornworms, and other eusocial wasps and bees, cannot actually digest solid protein. Instead, they mash their kill into a paste and feed it to the larvae. In return, the adults then feed on larval saliva. Without the larvae, the adults would starve. Outside the nest, it’s weirder still: V. mandarinia is the only Vespa species that engages in frequent extranida trophallaxis, that is, feeding outside the nest via regurgitation. They’ll eat tree sap; starving workers will beg others for the sweet vomitous kiss of food sharing and then the feeder and the feedee will embrace, rolling on the ground or hanging by a tree, until the goods are sufficiently shared. Yum.

Which brings me to the topic of hunting: Asian giant hornets are they only eusocial hornet species that stages group attacks against beehives and other eusocial wasp nests. I think it’s fair to say that “stages group attacks" is a rather polite euphemism for the gruesome murders V. mandarinia likes to drive through its neighbors, but I’ll let you be the judge of that.

The attack has three stages, beginning with the hunting phase. Solitary workers will hang out near the entrance to target hives and nests and capture inhabitants on their way home. Their prey is bitten to death, decapitated, legs and wings removed before taking home the snack to Junior. The hunting phase can go on indefinitely.

The next phase is called - and I am being completely serious - the slaughter phase. Scouts mark the target hive with pheromones signaling the impending killing spree; up to fifty hornets will attack the hive, staying close to the entrance, killing all counter-attackers. During this phase, the bodies of the dead are ignored. Once the slaughter phase has begun, the hornets will not stop; if it’s a lengthy fight, some will starve to death. In slaughters directed at the popular target, the European honeybee, the attacking Asian giant hornets are rarely killed. The European honeybees are virtually defenseless; their home will be decimated, the surrounding area littered with decapitated heads and torn-off wings. Attacks on a European honeybee hive by 20-30 Asian giant hornets will usually result in the deaths of up to 25,000 honeybees within one to six hours. The slaughter phase continues until the defense is ceased.

Finally, the occupation phase begins. The victors become territorial, audibly clicking their fearsome mandibles if their spoils are approached, some even spending the night in their newly acquired hive. The victors eat the honey and take the nutritious larvae home to the nest, feeding the spawn of their conquest to the next generation of conquerors.

But it’s not all wholesale honeybee slaughter. While European honeybees struggle and fight to their ultimate demise, Japanese honeybees have had enough of this shit. They fight back. It’s literally - and I mean this genuinely, not in some colloquial ironic bullshit sense - one of my absolute favorite phenomena in all of nature that I’m aware of to date. Hold on to your butts, this is going to end on an up note.

When a V. mandarinia scout finds a hive of Japanese honeybees, the bees do not react. While the scout enters the hive, they wait. Ignore. Their call to action is coming, the spray of tell-tale pheromone that marks their home for destruction. When that call is heard, the bees swing their abdomens side-to-side, signaling their plan.

They wait, shaking their bodies, until the hornet is close to leaving. Patience, girls. Then, with the swiftness and the fury, the bees swarm the intruder.

The bees, hundreds of them, too immediate in their motion and many in number for the hornet to fight off, have engulfed the harbinger of their assassination. But they do not end there. No, in a display of behavior that makes me shriek with unfettered glee, they begin to vibrate.

They bees are raising their collective temperature. The heat of the mass, furiously shivering, smothering the hornet, begins to increase. They are going to cook the hornet.

Hornet encased, the Japanese honeybees raise the temperature of her entombment to 117 degrees Fahrenheit.

The Asian giant hornet can withstand temperatures of up to 115 degrees.

But the Japanese honeybee can withstand temperatures of up to 118 degrees.

The threat to their hive dies with the scout, baked and motionless and silent. An outrageously incredible reminder that while Nature wants to kill you, she also wants to murder everything else.

The best part? National Geographic even has a video of the kill, complete with thermal imaging. Don’t say I never did anything nice for you.