Venomous and Underrated: Hymenopteran Horrors

I have a penchant for particularly noxious lifeforms, the ones that have evolved nasty chemical tools for either fending off bigger, badder, and hungrier things, or bringing down breakfast. Anyone who has read the breadth of this blog should now be aware of my adoration of the biology of such fundamentally antagonistic critters, the mark of which has been left behind in the number of entries devoted to the lesser-appreciated toxic flora and fauna of the world. Deadly, toxic mushrooms. Boxfish, with their poisonous mucus. The terrifying, seafood-driven, hallucinatory rollercoaster ride of ichthyoalleinotoxism. Pungent vinegaroons and acrid harvestmen. Venomous caterpillars that make you bruise like a peach….to death. Birds that silently embed concentrated toxins in their fucking feathers.The “Do Not Touch” exhibit in the Museum of Life has made a strong showing within the overall theme of Shit You Didn’t Know About Biology. I mean, Christ, my very first post on here was about an insatiable aphid-slaughtering deathdozer that bleeds poison foam.

Most of the unsavory representatives above are of a particular variety of being, well, molecularly disagreeable. Up until now, I’ve chiefly yammered on about “poisonous” and “toxic” organisms (with the exception of that intimidatingly venomous caterpillar), things that secrete or store harmful compounds in or on their bodies, such that the aggressor the poisons are intended for must passively absorb the toxins through digestion, or through the skin and mucus membranes (considering my research on boxfish, this bias towards this type of defensive strategy shouldn’t be all that surprising). Nature also hosts plenty of “venomous” organisms, which entails a much more direct, Type A approach to chemical warfare, wherein the poison punch is forcefully injected via a (generally quite pokey) delivery system that has evolved specifically to fuck up your day.

There are plenty of well-known venomous superstars, and it is especially the venomous snakes and spiders that garner the lion’s share of the limelight. A fair number of people are familiar with the superlatively deadly representatives of these groups, from sea snakes, cobras, and taipans, to Brazilian wandering spiders and Sydney funnel-webs, which regularly make appearances on just about every heavy-handed, suspense-saturated, kitschy “TOP TEN DEADLIEST” daytime special to run on Discovery, Animal Planet, or Nat Geo for the last decade or so.

But the brush painted by the evolutionary strategy of venom is broad, and the technique has cropped up in a surprising number of very distantly related lineages. This two-part series of posts will be devoted to the unsung venomous animals, which neither slither through the grass or canopy (nor thwart the professional efforts of John Goodman), and within their ranks, not even necessarily the most dramatically dangerous or traditionally telegenic and charismatic representatives. These other animals, however, have evolved injectable weaponry that is truly remarkable on its own merits, by a diversity of metrics, despite not achieving comparably towering levels of renown. Much attention has been bestowed upon the black mambas and black widows, the Clooneys and Jolies of venom notoriety. It’s appropriate to give the Goldblums and Leguizamos their day in the sun for once.

When it comes to animal diversity, insects are an undisputed juggernaut. Their taxonomic class, Insecta, potentially holds as many as ten million species…but it’s a quantity we can never quite pin down, since we continue to discover truckloads of never-before-seen creepy-crawlies just about every goddamn time we peak into the dark, dank undergrowth of equatorial rainforests, so our admitted level of ignorance tends to be a moving, inflating entity.

But there is one insect group within this overwhelming ocean of species, more than any other, that has forced humans to have an intimate familiarity with the throbbing cruelty of venom. This group numbers 150,000 species strong or more, and is found on essentially every major landmass on the planet. Entomologists know them as the Order Hymenoptera. To most everyone else, they are the bees, wasps, hornets, and ants. Hymenopterans, as a group, are responsible for more annual human deaths then just about any other venomous clade. In the U.S. alone, about 40 to 50 people die from just bee stings every year. Part of this is explained the by the allergenic properties of hymenopteran venom, and how severe allergies to stings aren’t all that uncommon. The other reason is tied to contact; the angry, swarming, stinging bastards are everywhere. Large numbers of humans have had heated interactions with hymenopterans at some point in their lives. Whether it was stumbling over a yellowjacket nest, or getting a little too close to that arboreal, roadside beehive, the transgression invites a cloud of livid, buzzing pain-missiles upon their panicked, flailing selves. The burning of potentially dozens of stinger-fulls of venom is an experience billions of humans learn to carefully avoid.

Personally, I regard hymenopterans with a severe level of caution; not because of an allergy to their stings, but because of my near-phobic degree of fear in their presence (a feeling of unrelenting trepidation that also has driven a fascination and respect for their incredible biology). But even I had to learn their venomous nature from early, first-hand encounters. My earliest interaction with a bee occurred when I was three years old, playing in my grandmother’s landscaped front yard. I was convinced that the silly, fuzzy, striped bug sniffing all the flowers would feel nice and soft in my pudgy toddler hands.

It did not feel nice. It did not feel nice at all.
I haven’t felt comfortable around bees since. First impressions fucking matter.

Beyond your common honeybee or picnic-crashing ant, there are a number of famed members of the hymenoptera long recognized for their especially brutal stings. These Celebrities of the Sting are worth mentioning briefly, if for nothing else but to get their prestigiously painful asses out of the way. For one, the fire ant (Solenopsis invicta), native to tropical South America, has a well-earned reputation for aggressively defending its colony by vigorously stabbing trespassers with a decidedly painful venom, resulting in the eruption of searing blisters and, potentially, anaphylactic shock. Fire ants have commanded worldwide attention due to their status as a hard-to-eradicate nuisance and invasive species in the Southern U.S., parts of East Asia, the Caribbean, and Australia (a place that certainly doesn’t need more cantankerous beasties). Then there’s the fire ant’s notorious cousin, the bullet ant (Paraponera clavata), also native to the Neotropics. This gargantuan black ant, burly enough to hug a penny, is thankfully not established anywhere outside of the deepest recesses of Central and South American rainforests, because it harbors a sting widely regarded as the most painful on the planet. That name? Bullet ant? It has nothing to do with its 400 m dash time or its NRA membership. No, it’s called the “bullet ant” because its sting makes you feel as though you’ve been fucking shot with a handgun. You then endure the wonderful experience of unabating, unfathomable quantities of madness-inducing agony, making you sweat and tremble uncontrollably for what seems like an eternity of supernaturally savage punishment.

If you’ve ever sat through the 91-minute runtime of this cinematic abortion, you’ll know the feeling

But lastly, buzzing ominously above the zenith of hymenopteran sting infamy is the Asian giant hornet (Vespa mandarinia), very recently made familiar to the world outside of its native East Asia thanks to nature programming and the collective gasping and shivering of a generally entomophobic Internet. I’m not entirely certain why, seeing as how it’s fundamentally no different than a normal hornet….except for how it’s bigger than a canary, has a quarter-inch long stinger, and is consequently the most distilled, pure incarnation of “hell fucking no” to ever exist. And how they spend their time nonchalantly pinning down things more than twice their size and chewing off their faces. And how they violently dismember European honeybees faster than Spartans mowing through Persians in a Zack Snyder film. And how they do things like this to the most fearsome, heartless insect predators around:

Yes, it’s eating a praying mantis. And yes, you just peed a little.

Oh, and then there’s that whole thing about how when it plunges that jumbo-sized stinger, which is as thick as a motherfucking thumb tack, into your delicate, mortal flesh, it feels like “a hot nail” being driven through you. It’s less “bee sting” and more “getting stabbed with a soldering iron.” The volume of venom unloaded by these stings is likely three times higher than what more modestly-sized hornets dole out, and because of this, a comparably low number of stings can be life-threatening, even for the non-allergic. Seriously, particularly bad attacks of Asian giant hornets end up killing people by the dozen on the reg, immense volumes of venom turning their organ systems to jelly.

So, yes, perhaps no hymenopteran is as viscerally manhood-wilting as Vespa mandarinia, but in actuality, the world’s largest hornet only holds a title in regards to its girth. Part of the reason so many people are killed and injured (as many as 1,600 in what probably seemed like an astoundingly apocalypse-y year for northern China), is because this hornet is common in low elevation forested habitat near some of the densest aggregations of humans on the planet; Japan and coastal China. This means that humans and giant hornets are relatively likely to run into one another. Despite its overall lethality and destructiveness to human happiness, this yellow-and-black, colon-purging nightmare isn’t especially venomous as far as hymenopterans go.

To find the possessor of the most potently pernicious posterior prick among wasps, one must go to the Philippines and hunt down the Asian giant hornet’s relative, Vespa luctuosa. This hornet, endemic to the Philippine archipelago alone, doesn’t have a common name, which opens the door to me coming up with one on my own for the sake of ease. The Philippine fucker-upper. The Manila killa’. The Pinatubo painmaster. But perhaps simply “Philippine hornet” will work better here. In life, the Philippine hornet doesn’t really stand out from the hornet pack. It lives a standard, tropical hornet life, crafting spherical papier mache nests that hang from rainforest trees like the world’s least enjoyable piñata. It has a notably darker coloration than many hornets, with only a few thin, rogue bands of deep yellow appearing at the back of the abdomen near the stinger.

Yeah, dark…like its soul
Photo: Lary Reeves

Additionally, the Philippine hornet is something of a hermit, generally not associating well with human encroachment and keeping to itself in undeveloped regions of the hot, humid rainforests it calls home. This is definitely for the best, since this drab hornet has a venom whose potency ranks highest among wasps, and is one of the most potent of any insect, period.

Toxicity of substances is often given as an LD50 value (or a “median lethal dose”), which represents the dosage of venom needed to, statistically, kill 50% of a given population of a test animal. Often, this dosage is listed as milligrams of venom per kilograms of mass of the poor, envenomated subject sacrificed on the lab bench (often a mouse). The value also tends to vary with how the venom is injected (below the skin vs right into vein, for example). The lower the LD50, the higher the toxicity, since a lower concentration is needed to achieve a 50% kill rate. The Philippine wasp’s venom has an LD50 of about 1.6 mg/kg in mice, and in contrast, the imposing Asian giant hornet has venom achieving a value of over 4 mg/kg. Compared to the most venomous snakes, like Pseudonaja and taipans, this is 10 to 100 times less potent. Philippine hornet venom is more on par with that of the king cobra (Ophiophagus hannah) in drop-for-drop deadliness. If the idea of hornets flying around with honest-to-Jiminy-cocksucking-Christ cobra venom in their stingers makes you sweat like Ned Flanders in a strip club, consider that envenomation volume makes a huge difference. The king cobra can pump out as much as seven milliliters (a quarter of a whiskey shot glass) of venom in a single bite, but the sting from a single Philippine hornet is going to dispense a tiny fraction of that amount. However, this venom is potent enough that each hornet possesses enough venom to statistically kill a dozen mice; meaning, that if you took their entire load of venom, and distributed it among twenty-five mice, statistically, half of them would die. That’s not “cobra serious”, considering that hornets don’t blow their whole venom load in a single sting, but it’s conceivable to see how an uncoordinated trailblazing effort, a clumsy collision with a colony, and dozens of stings later might put your ass in some hot water, sting allergies not even considered.

This one has a pin sticking through it, and is a dried-out, four decade-old corpse, which makes it slightly less dangerous than normal.

“Well,” you say, sitting in the air-conditioned comfort of your home in the Tempe ‘burbs, “it’s a good thing I don’t live in the Philippines.” Sure, you think, living in Arizona, Earth’s scrotum-melting broiling pan, has its own throng of difficult residents that goes along with it. Rattlesnakes. Scorpions. Gila monsters. Homophobes. Racists. Racists. Still more racists. Racists everywhere. Did I mention racists? But you can adjust to all of that in time, and through simple things like developing a drinking habit and never going outside during the daytime. It’s not like the most venomous insect on the planet could potentially skitter up to my sun-scorched doorstep or something.

Oh yeah, except for how that’s totally a thing that can happen.

North, Central, and South America are home to a genus of ants (Pogonomyrmex) collectively known as “harvester ants.” They are a diverse group, and about seventy species of Pogonomyrmex run frenetically across the hot, arid regions of the New World. They, much like the aging Tucson hippies they share their habitat with, are seed-eating specialists, and workers forage for small seeds to take back to their subterranean nests. They are industrious little creatures, and as a result, there tends not to be much in the way of vegetation growing near the entrances to their colonies, the landscaping dominated by sand and gravel. Outwardly, they are unremarkable as far as ants go. Small. Bent antennae. Six legs. Pinched waists. Bullet-shaped butt and a round head. Chastises Grasshopper for being an ever-idle moocher. No surprises here.

That is the most anty-looking ant I’ve ever seen.

Look a little closer though, at the far right, at the teardrop tip of its shiny, caramel abdomen. See that sliver poking out through the white bristles there? That is a stinger, not unlike that of the Philippine hornet or any other typical hymenopteran.

It’s important to remember that while ants are a big group, with a towering number of species in their ranks (somewhere between 12,000 and 20,000+, it’s hard to tell), they all reside within a single taxonomic family (Formicidae). A family, by the way, nestled among a whole suite of families of “wasps” in a superfamily cluster termed the “vespoids” (which are all your typical, yellowjackety, waspy type creatures). Ants are just a group of specialized vespoid wasps that have taken to the ground and lost their wings. Well, most of them. Many species reserve the retention of wings for a select few social castes. Ants are newcomers among insects, diverging from their wasp brethren only within the last 120 million years or so, and it’s easiest to think of the family as simply wasps with a few modifications. Certain features of their biology and anatomy betray their ancestry, and more so in more primitive groups of ants. For example, a powerful, painful sting tends to associate with groups of ants that were earlier offshoots within the family; the notorious bullet ant, with the most brutal sting of all, is a member of a comparatively ancient group of ants known as poneromorphs. In the “canopy” of the ant family tree reside lineages that have lost stings altogether, converting their venomous butt darts into a contraption that sprays formic acid.

Pogonomyrmex is one of those ants that holds onto the weaponry of its aerial forebears with as much tradition-rescuing, white knuckled zeal as an 80 year-old defiantly maintaining that the restaurant down the street serves “Oriental” food. And boy, have they found a way to make it their evolutionary nostalgia count. Harvester ants, as a group, have the most venomous stings of any insect, with the highest honor falling upon Pogonomyrmex maricopa, a nondescript ant found chiefly in the Sonoran and Chihuahuan Desert regions of Arizona, but actually ranges through the adjacent desert lands of Utah, Nevada, southern California, and New Mexico. This species has the most potent venom of any insect, with an LD50 recorded at 0.12 mg/kg. For context, consider that this is more than ten times more potent than the already hyper-venomous Philippine hornet’s sting, and has a similar punch to the venom of the Russell’s viper (Daboia russelii), a snake infamous for killing thousands of people across South Asia every year. From the human perspective, these guys are itty bitty, and each sting delivers a minuscule dosage of venom. But it does the job, and the result is several hours of hot, blinding pain, effectively making Pogonomyrmex maricopa‘s sting the most aggressively repellent thing to hit the Grand Canyon State since Joe Arpaio flew on in, powered solely by jowl oscillations and hot air.

But why have such a dickishly venomous sting? Not all ants, apparently, have the need to be so outlandishly nasty, so why the harvester ants? The answer lies in how venoms evolved in hymenopterans. Hymenopteran stingers evolved from the egg-laying tubes (called an “ovipositor”) of females to dispense a painful, toxic chemical “persuader” to unwise attackers of a colony or nest. The entire point of these venoms is to induce enough torment that a nest raider loses all motivation to complete Operation Tear Open the Humming Food Ball, and instead limps off to engage in Mission Lick Wounds and Whimper Self to Sleep. It also helps if the experience is agonizing enough to keep the intruder from returning without a careful evaluation of its life choices. The sting of a hornet or an ant is there for defending the hive or nest, often from something big and hungry. So what the hell are the harvester ants defending themselves against that would necessitate the evolution of such potency?

Enter the Texas horned lizard (Phrynosoma cornutum), a thorny, squat, tank-like lizard that makes the arid lands of the interior Southwest its home. Biologists know it as a member of the diverse group of “North American spiny lizards” that are found all over the continent, but you may know it as that one lizard that can turn its blinkers into a blood cannon or as the star of the “Laughing Lizard” Internet meme. The Texas horned lizard may look a little comical; it’s hard to take seriously an animal that looks like a combination of a frog and a cactus that was run over by truck. But when it comes to eatin’, this lizard doesn’t fuck around. The Texas horned lizard, fitting right in with the Lone Star State crowd, has a heightened culinary appreciation for spicy food, as more than two-thirds of its diet consists purely of Pogonomyrmex ants. This is an animal that trains its blank, saurian gaze on a pulsating, angry, red mound of toxic fury and says “yeah, I can eat that.” The horned lizards, as a group, are harvester ant-eating specialists. I really mean “harvester ant specialists” too. They target these picante pricklers only, and will forgo eating things like invasive fire ants, which is actually the less venomous, “pico de gallo” alternative, and rigidly stick to their native, “ghost pepper” option. This is actually a conservation problem for horned lizards, because invasive, omnivorous fire ants are currently killing and eating harvester ants at a breakneck pace…eliminating the bulk of the horned lizard’s diet, leading to falling lizard populations.

There’s evidence to suggest that the super-charged stings of harvester ants are the result of such aggressive, narrowly focused predation, resulting in a coevolutionary feedback loop, where the ants evolve even stronger stings, and in response, the horned lizards come back them with the evolution of even better venom tolerance. It turns out that horned lizards are really goddamn good at absorbing Pogonomyrmex stings. How good? Better than mice, that’s for sure; the LD50 for Pogonomyrmex maricopa venom in horned lizards is 162 mg/kg. This means that it takes more than 1,300 times more venom to, statistically, kill as many horned lizards as it does mice of the same size. The difference in venom tolerance between horned lizards and close relatives is huge as well, just in case you thought it a reptile-vs-mammal thing was to blame; the LD50 for the venom in the fence lizard Sceloporus is a sixth of what it is in Phrynosoma cornutum. The resistance appears to be something running through the lizards’ inner piping, because when you inject mice with horned lizard blood plasma, the some of that resistance to the ant venom is transferred over. Horned lizard physiology casually shrugs off harvester ant venom proteins, handily detoxifying the deadly cocktail like it was nothing more than baby aspirin.

Horned lizards also avoid getting too much venom into their bodies in the first place by incapacitating the ants. However, this happens much later in the “eating chronology” than most people would prefer for consuming an army of six-legged hellfire. Horned lizards rapidly gobble down the ants whole, attempting to eat dozens in a single sitting. When the wee bastards enter the digestive system, they are very alive and more than a little piqued. Before they can arch their abdomen back and unleash a bout of heartburn that reptile won’t soon forget, they are enveloped in thick, heavy mucus, and frozen in place as they are shuttled down into the stomach. Horned lizards have evolved a series of unique, finger-like projections and folds that line the inside of their upper digestive tract and produce copious amounts of snot that binds and immobilizes the ants as soon as they get swallowed. Horned lizard gullets are like a water slide, but pitch black and full of molasses. They can shovel ants in their mouth freely, never worrying about hymenopteran havoc being wrought on their vulnerable stomachs. I guess you can say all that protective phlegm acts as an….ant-acid.

See? He thinks it’s funny.

The combination of this, and how they brush off harvester ant venom like Bukowski brushing off half a handle of bourbon, allows horned lizards to fill up on the most painful meal in the desert in relative peace, unaware of the silent, coevolutionary war taking place between them and their food for hundreds of millennia.

You may have noticed that the correlation between venom potency and danger to humans isn’t very strong when it comes to these insects and their stings; Asian giant hornets kill heaps of people annually, but have relatively mild venom, and the chemically formidable stings of Philippine hornets and harvester ants may hurt like shit, but haven’t really been associated with human fatalities. Are there any ants, then, that somehow manage to summon EMS sirens wherever they clash with humans, despite their relatively dinky potency?

The answer is yes, and they can be found in Australia. Because of course they fucking can.

Australia is no stranger to periodically murderous wildlife, especially of the venomous variety. Hell, half the examples of highly-venomous snakes and spiders I’ve mentioned in this blog post hail from Oz. The entire goddamn island continent is awash in a diversity of venomous animals, a disturbingly high proportion of which are armed with venom vicious enough to drop your carcass to the hot, antipodean dust for one of those “forever” kind of naps. I’m half convinced that koalas and wombats aren’t real animals, and were artificially contrived by the Australian government to distract tourists from the ever-present, shin-deep layer of funnel-web spiders blanketing the country. I suspect Australia is so damn dry because rain is simply too afraid to fall there. What I’m trying to say is that Australia is what’s on the other side of the inter-dimensional, fog-bound portal in The Mist.

So, it is no real surprise that something as cartoonishly intimidating as the bull ant (Myrmecia) feels comfortable enough to make its home there.

That right there is about two centimeters of NOPE

They are an old, primordial group of ants, with essentially no close living relatives. Their primitiveness is readily observable in their social structure and the loose delineations between castes. They aren’t nearly as cohesively cooperative with one another as more recent ant groups. There’s more of a libertine, laissez-faire approach to things, with more infighting, and less collectivist, colony-driven, group motivations. The division of labor isn’t as well-pronounced, nor is the presence of physical differences between reproductive and worker castes. For example, they are among the few lineages of ants that, in addition to a queen, possess “gamergates” in their colonies; worker females that retain the ability to mate with a male and reproduce. The fossil record shows that back in the Cretaceous, bull ants had a large geographic range, extending onto just about every continent. But, in the modern age, the remaining hundred species of ant in the genus Myrmecia are all found only upon the continent of Australia (save for a single species holding out on New Caledonia, a nearby group of islands between Fiji and the Solomon Islands). Apparently, this is an ant that liked to live dangerously, and after the dinosaurs went worm counting, the only place left that was treacherous enough to set up shop and keep the adrenaline pumping was fucking Australia.

An encounter with Myrmecia in the flesh truly does engender the feeling that they hail directly from a bygone prehistoric age, full of harsh challenges that the lily-livered ants of today could never even imagine. For one, the worker ants are gigantic by ant standards. While not the largest ants in the world (surpassed by the famous, previously mentioned bullet ant, and the tocandira), many bull ant species can have a worker caste that can nearly reach an inch and a half in length, which is longer than the distance between the tip and first knuckle of your thumb….not that you’d ever want to get your hand close enough to measure. Secondly, you may have noticed that bull ants have a set of weaponry that most ants do not; serrated, pinching jaws, longer than the head, extending forward like a pair of cruel bread knives. These mandibles aren’t just for show, and can snap together with blinding speed and savage force, puncturing and clenching whatever is in their path. Bull ants have pneumatic meat hooks where their face should be.

Aww, look! She’s smiling!

Evolution has molded these ant mouthparts (which are normally quite modest in other genera of ants) into Satan’s pinking shears, and they have a key job in the life of the bull ant. And while I know they are intimidating to look at, no, it isn’t killing and dismembering buffalo. The adult ants are omnivores, eating everything from nectar, to fruit, to seeds, to the liquefied remains of small insects…but their maggot-like young are fully carnivorous, and require a fresh, dripping kill to grow up big and strong. So, adult bull ants lead an active and athletic foraging lifestyle, usually solo, using their big eyes and keen eyesight to track down prey from surprisingly long distances away. Bull ant workers then use those brutal chompers to pin down anything they can in a vice grip; grasshoppers, beetles, more pusillanimous species of ants, and, in a bizarre table turn of food web convention, spiders. Yes, spiders. Charlotte’s Web would have ended slightly differently were it set in Australia.

“Wilbur! Wilbur, help! Wil-ggaaaaghhh!!!”

But the killing blow to their wriggling, soon-to-be-baby-food quarry comes from Myrmecia‘s venomous sting. And it is their sting, not their bite, that makes bull ants dangerous to humans. In fact, one small, common species, Myrmecia pilosula, the “jack jumper”, so named for its habit of lunging and bouncing when disturbed (a similar behavior is seen in Myrmecia gulosa, the “hoppy joe”), is responsible for several human deaths, and is the cause of many hospitalizations in Eastern Australia and Tasmania. Bull ants like the jack jumper and hoppy joe may have disarmingly ridiculous, very Australian nicknames that sound more like a brand of small firecrackers and a rabbit-themed coffee shop, but it is clear that their venom is nothing to giggle at.

The jack jumper is an ant that shies away from the dense urban habitats of Australian population centers like Melbourne, Brisbane, and Sydney, but is common in open, more undeveloped areas all over the country. They easily stake their claim and establish colonies on the borders of suburbia and rural regions, and as a result, humans regularly spot them and are stung by them when engaging in outdoor activities. This is a problem, because the venom from these ants is apt to kill people dead.

The deadly nature of Myrmecia venom isn’t related to a blanket potency. Realistically, bull ant stings generally aren’t particularly venomous, on their own, compared to other hymenopterans. Much of the time, a jack jumper sting results in a painful boil and local swelling that persists for a few days, similar to a fire ant sting. Not much is known about the venom’s calculated potency in whole animals, but pilosulin 1, a protein in jack jumper venom, is known to have an LD50 concentration value for a certain type of white blood cell that is four times lower than melittin (a major component of bee venom).

However, it isn’t the straight toxicity of compounds like pilosulin 1 that make a jack jumper sting potentially deadly, it’s the uniquely allergenic properties of the venom. Jack jumper stings are dangerous because a shitload of people have severe allergic reactions to them. In Tasmania, where jack jumpers are highly abundant and cause the majority of severe stings (and resulting deaths), the prevalence of severe allergies to stings sits at around 3%, twice as high for honeybees (a hymenopteran famous for getting the immune systems of countless humans to self-destruct with deadly consequences). Unsurprisingly, the same study linked to above has shown that as many as one in fifty Australians have reported anaphylactic reactions to stings from jack jumpers or other Myrmecia ants. In Australia, most anaphylaxia cases from insect stings are attributed to jack jumper ants, not from bees, making Australia possibly the only place in the world where bees are beaten at their own immunogenic game.

Not only are jack jumper stings more likely than bees to send you to the hospital, a pale, swollen, barely breathing mess a step away from death…but they are more likely to do it more than once. If you’ve had a major allergic reaction to a jack jumper sting, and you get stung once again, you might not want to wait until the symptoms get bad before you get the fuck to the hospital. There’s a 70% chance that this repeat sting will initiate a catastrophic allergic reaction just like the last time. For honeybees? It’s about 50-50. About half as likely than that for wasps. Myrmecia stings do what honeybee stings do, but they do them better. Better than an animal that, generally speaking, is really damn likely to kill you…more likely to kill you than pretty much any other.

This potent allergenic effect probably isn’t mitigated at all by another protein in jack jumper venom; pilosulin 5. Pilosulin 5 causes mammalian mast cells to dump buckets of histamine all over the place…you know, the same crap that basically causes all symptoms of every allergy ever.

The jack jumper issue has been so bad for so long in Tasmania, that around a decade ago, an immunotherapy program was set up to desensitize the particularly allergic to the venom. It has been largely successful, and it, along with enhanced public awareness of the dangers of the venom, has contributed to a sharp decline in jack jumper sting deaths in the island state. Until the start of the new millennium, someone perished at the butt-end of a jack jumper once every few years, but there hasn’t been a recorded death that can be attributed to the ant for more than a decade now.

Hymenopterans and their venom manage to reign supreme in the insect world, but underappreciated venomous critters abound in many lineages and environments. To see some, you may have to plunge into tropical, coral reef waters, and for others, just go for an off-trail jaunt on your next backwoods hike…. (continued)

Image credits: Intro image, giant Asian hornet eating mantis, pinned Vespa luctuosaharvester ant, Myrmecia and ruler, jack jumper close-up, Myrmecia catching spider

© Jacob Buehler and “Shit You Didn’t Know About Biology”, 2012-2015. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jacob Buehler and “Shit You Didn’t Know About Biology” with appropriate and specific direction to the original content.


4 thoughts on “Venomous and Underrated: Hymenopteran Horrors

  1. I live in Australia, and have met the Jack Jumper ants. Although I just called them ‘fucking jumping bull ants’, my Dad cut through a nest of them with a chainsaw. He was just trying to get a massive Staghorn fern off the log for my Nan. He got about 12 bites from them and felt rather sick, I was worried then. Seems I was justified. And that he was very lucky. I’m going to tell him to stay away from the little bastards. Although he did say the stings were very painful, so it’s likely Nan never did get that Staghorn.

    • Yeah, I wouldn’t go back after that staghorn fern either! The stings are one hell of a deterrent, and yes, if he had a potent reaction like that, being worried is certainly appropriate. I write about Australia and it’s wildlife quite a bit (because there is a LOT of fascinating stuff on your continent to talk about!), but I’ve never visited myself. I know that whenever I do make it out to your neck of the woods, I’m going to find myself some of these venomous local buggers and say hello…hopefully without a visit to the hospital.

  2. Pingback: Venomous and Underrated: Paralysis Ticks and Undersea Pricks | Shit You Didn't Know About Biology

  3. Aw, you didn’t even talk about another two of the most horrifically painful insects on the planet, both of which are also native to Arizona: the velvet ant and tarantula hawk. The first is the less painful, but tends to last about 30 minutes of agony given by an unnecessarily long stinger, and they second can cause localized paralysis from the pain.

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