Southern flannel moth - Megalopyge opercularis

Also known as the “puss moth” or “tree asp” (for its luxurious-looking “fur” and its extremely painful sting, respectively), Megalopyge opercularis is a deceptively cute tribble of a caterpillar found in the Eastern and Southern United States. It’s most common in Texas, but can be found along the Eastern Seaboard as far north as New Jersey.

Both the adult and juvenile forms of M. opercularis have urticating (itch-inducing) hairs on their body, much like some other caterpillar species, but the asp takes it one step further, and has clusters of venom-filled spines under its hairs.

As they most often live in popular shade trees, caterpillars occasionally lose their grip and tumble down onto unsuspecting humans just trying to have a nice day at the park. Their reproductive cycle means they’re particularly abundant in late spring/early summer and mid autumn. The sharp spines pierce the skin and automatically inject venom for as long as they’re embedded in the skin. Unlike with snakes, the caterpillars have no control over whether or not the venom is used.

Despite their relative abundance, especially in Texas and Louisiana, many doctors and first responders wouldn’t know the signs of an asp encounter if it crawled out of Donald Trump’s (clearly asp-inspired) toupee and stung them on the nose.

Most patients (but not all) experience extreme pain at the location of the sting, and that pain often radiates to the nearest lymph nodes. Swelling occurs at the sting in a raised halo, which then recedes to show the pattern of the spines on the caterpillar (lower image). While the pain rarely lasts longer than 48 hours, some patients may experience lymphadenitis (swelling of the lymph nodes) for up to a week.

So what do you do if you’re unfortunate enough to directly encounter a tree asp?

Step 1: Cellotape! Or scotch tape, whatever you call it. Take a strip of it, put it over where the asp landed/got squished/you had the bad idea to pick it up. Remove it. Repeat several times. This helps get out any spines (which can be near-invisible) stuck in the skin. Protip: This is also useful if you ever fall into a cactus. Believe me. I’d know.

Step 2: If the pain is super intense, see a doctor. Bring with them any information about the bug that you can, but maybe don’t bring the actual caterpillar unless you have a way of handling it without getting stung again. If it’s just really bad (no, seriously, these things can bring grown men to their knees), take some anti-inflammatory drugs (such as ibuprofen or tylenol), some anti-histamines, or both.

Step 3: Wait. Sorry bud, this next day or two is gonna suck. Ice the area if you want, to numb it up. Have a beer. Eat some ice cream. Watch a movie. Try not to think about it.

If you have any trouble breathing or seeing or any other serious symptoms go directly to the emergency room. Tell them what stung you. They might not know what to do off the top of their head, but they have resources!

Read More:

Puss Caterpillar (Larva), Southern Flannel Moth

Images:

Wikimedia Commons

The Puss Caterpillar and the Effects of its Sting on Man, USDA Circular 228. F. C. Bishopp, September 1923.

Boomslang - Bucephalus viridis [now Dispholidus typus]

Where the elapids and viperids have fangs at the front of their mouth for easy envenomation, boomslangs (a member of the Colubrids) are equipped with regular teeth at the front of their mouth, and venom-injecting fangs at the back. Because of this, even though their venom is extremely hemotoxic, they rarely are able to inject enough into a larger animal (such as a human) to cause death.

However, the bite of a boomslang is not to be underestimated - as it's not always clear when the fangs have punctured the skin due to the other teeth leaving puncture wounds, medical help should always be sought out. The venom is almost completely hemotoxic, and the lack of neurotoxic symptoms can lead bite victims to believe that there was either no envenomation, or that they can just wait for their body to process the toxin.

This mindset is what led to the 1957 death of esteemed herpetologist Karl Schmidt. He believed that the amount of venom he received was negligible, but 28 hours later his blood was so thin that it was coming out of every hole in the body, including his eyes and ears, and no amount of medical treatment could have saved him. Early antivenin administration is critical.

Luckily, even if you're in its natural habitat (forested areas in sub-Saharan Africa), you will probably never encounter a boomslang in the wild. They're timid, generally dwell in trees more than 20 feet above the forest floor, and would much rather eat a small bird than waste their venom on a human. Most bites occur when someone tries to handle or kill one.

Illustrations of the Zoology of South Africa: No. XXII. Andrew Smith, March 1845.

Ways to Die: Snake Venom

The vast majority of snakes that one encounters in the wild (unless you live in Australia or India) are either non-venomous to humans or want nothing to do with you.

However, should you stumble upon a rattlesnake nest or coral snake hole while texting in the middle of nowhere, there will probably be a combination of different enzymes and polypeptides pumped into your body, via the modified parotid salivary glands (right below the ear in humans) that snakes have evolved over the ages, to disable their prey. Of course, you're not prey, but you stepped on a snake while texting. It has every reason to envenomate you.

While all snakes have multiple active enzymes in their venom, all snakes dangerous to humans have either neurotoxins or cytotoxins as a significant component in their venom. For the most part, elapids (such as the cobras and mambas) create neurotoxins, while the viperids (such as vipers, adders, and rattlesnakes) create cytotoxins.

Neurotoxins

Cytotoxins

Images: Top: Bungaris fasciatus - Banded Krait. An elapid, and the largest of the kraits. Has neurotoxic venom. [source] Center Right: Hydrophis robusta [now Hydrophis spiralis] - Yellow Sea-Snake. The longest sea snake, at 3 m (9.8 ft). A member of the Hydrophiinae, separate from other elapids. Though they have some of the most toxic venom in the world, bites are extremely uncommon and often unnoticed. [source] Center Left: Vipera russellii - Russell's Viper. A particularly aggressive viperid. Necrosis and amputation following envenomation not uncommon, due to hemolysis and local cell damage. [source] Bottom: Vipera caudisona [now Crotalus horridus] - Timber Rattlesnake. A venomous viperid endemic to the United States. Primarily hemotoxic venom, very low fatality rate, but very painful bites. [source]

"Death" Gaboon Viper - Bitis gabonica

Despite the fact that the Gaboon viper ends up on many of the lists of "World's Deadliest" or "Most Dangerous" animals, it's actually not anywhere near the threat that you might think. Similar to the Australian sea snakes (with some of the deadliest venom), its docile nature renders the fact that it produces the highest volume of venom much less of a threat than, say, an aggressive snake with a small amount of venom.

Granted, you shouldn't go around picking these guys up or threatening them, but they don't chase down intruders or threats.

Bitis gabonica is the largest of its genus (commonly known as the puff adders), and at 8.5 kg (19 lbs), is the heaviest viperid in the world. If they do manage to get a bite on someone, the hemotoxic venom can cause internal bleeding, shock, local blistering, and eventually necrosis and the need for amputation, if not treated immediately.

ETA: Apparently the Gaboon viper also has the longest fangs of any species, and that, combined with the fact that they produce the most venom and that when they DO bite, they inject venom about 3/4 of the time (as opposed to 1 in 4 times for most viperids), is why they end up on all of these "most deadly" lists. I guess it fits. Docile and chill creature overall, but don't piss it off or you'll be hurting.

The Uganda Protectorate. Sir Harry Johnston, 1902.

The Giant Amazonian Centipede - Scolopendra gigantea

Like the other members of Scolopendra, the giant Amazonian centipede is predatory and venomous. The first body segment has a pair of modified legs terminating in sharp claws, called forcipules (you know, like forceps), which it uses to pull its prey to its mouthparts, where it injects its venom.

Though typically non-fatal to humans (excepting those allergic to the venom toxins), giant centipede bites are incredibly painful and can cause symptoms for days on end. This venom is what allows them to hunt prey as large as small mammals and birds, without itself being eaten.

I have no idea what people are thinking when they buy one of these, but they're apparently a big thing in exotic insect circles. They're known to be jumpy, nervous, and very aggressive both in the wild and in captivity, and can often escape enclosures that aren't well-sealed. I mean, come on. Even tarantulas can be docile and friendly. And mantises are fun to watch and not venomous! And there are so many other options! Why a giant centipede?

Vivarium Naturae; or, the Naturalist's Miscellany. George Shaw, 1790.

Graceful small-headed sea snake - Hydrophis gracilis [now Microcephalophis gracilis]

The graceful small-headed sea snake, or slender sea snake, is one of the members of the Hydrophiidae, a family of highly-venomous seafaring reptiles. Though they can function on land, many members of this species spend effectively their entire life at sea. Their habitat - the Indian Ocean, South China Sea, and Persian Gulf - has an average water temperature high enough to allow these snakes to not need any time "sunning" themselves.

Despite their highly venomous nature, most sea snakes (including this species) are very placid. They rarely bite, even when threatened - not that I'd advocate you approaching one! - but as they must hunt fish that are faster than them in the water, their venom is potent enough to immediately immobilize and kill even their largest prey.

Transactions of the scientific meetings of the Zoological Society of London. 1841.

Phospholipase A2 note:

[boring biochem technicalities]

Humans create their own PLA2 (I and II) that serve completely different functions than as a hemolytic enzyme (though an overload of PLA2 will act in that fashion). In fact, in general, they have a function more closely associated to neurotoxic venoms than hemotoxic ones - they typically bind to acetylcholine receptors and serve as a cholinergenic molecule. This is why some snakes utilize it in a fashion that causes a flaccid (limp) paralysis, including a failure of the diaphragm muscles to contract, leading to death by suffocation.

However, in some snakes (notably vipers and boomslangs), PLA2 is simply the primary protein in a cocktail of toxins that make up the venom. The other enzymes and molecules combine to create a potent hemotoxic venom that ruptures erythrocytes in a slow and steady manner, and get broken down by the body in an even slower manner.

[/boring biochem technicalities]

Hence, PLA2 in boomslangs = good lord you're bleeding out your eyes and ears and mouth and nose and probably other places

Heloderma suspectum - Gila Monster

Gila monsters are the close relative of the Mexican beaded lizard, identified in the early 19th century as the first truly venomous lizard. Gila monsters weren't described as a unique species until the mid-1800s.

Today, the unique peptides in their venom are being researched for use in a multitude of applications, such as schizophrenia, Alzheimer's, and ADHD. There is already a drug on the market derived from an enzyme created by the Mexican beaded lizard that is used in management of Type 2 Diabetes, and trials for drugs derived from the Gila monster are particularly promising in progressive dementia.

Animaux Venimeux et Venins. Marie Phisalix, 1922.

Xenestis colombiana [Xenesthis immanis] - The Colombian Lesser Black

This is one of the mid-sized (6-9 cm long) tarantulas, with a habitat that ranges from Colombia down through most of Peru and nearby countries. Like all tarantulas, the venom this spider possesses is of far less danger to humans than the threat of infection in the sometimes-large puncture wounds it inflicts. In fact, since 1900,  there have been only three recorded deaths by tarantulas in people without a known severe allergy to one or more of the venom's components, and all three of those people almost certainly had *some* predisposing factor for death, but no post-mortem testing was done/could be done.

Personally, I'm a lot more afraid of pissing off tarantulas because of their abdominal hairs. They use their back legs to flick off these extremely urticating (itch-inducing substance) hairs, and those things do NOT come out of your nose or eyes easily if they get in there. Don't annoy tarantulas, ya? You won't die, but you'll almost certainly regret it.  

Animaux Venimeux et Venins. Marie Phisalix, 1922.

Physalia pelagica [Physalia physalis] - The Portuguese Man-o-War

All the fascinating biological facts about the Portuguese Man-O-War aside, did you know that its name was actually coined as a derisive snipe at the Portuguese navy? Powerful and feared for centuries, they were in a period of steep decline during the 19th century. The appearance of the Man-O-War, especially when washed ashore, struck mid-century English explorers as a capsizing ship, or a sail with no boat to propel. 

In the end, I wouldn't call the name completely derogatory. This siphonophore is the epitome of pain for most people who encounter them...they may look goofy, but unless you're a loggerhead turtle, blue sea slug, or blanket octopus, it's still not much to laugh at. The first two creatures eat these guys as a main part of their diet, and the blanket octopus is apparently *crazy* and will rip tentacles off of the Man-O-War, waving them around as a defensive measure.

Animaux Venimeux et Venins. Marie Phisalix, 1922.

Pitohui variable (now Pitohui kirhocephalus) - The Variable Pitohui

Though all pitohuis have been found to have at least some level of toxin in them, the variable pitohui and hooded pitohui have by far the highest and most consistent levels of it, both in their bodies and throughout their feathers.

The toxins carried by the pitohuis aren't actually produced by them - like the Columbian poison dart frog, they acquire the toxin from their food sources. Actually, the chemical makeup of their toxin is almost identical to that of the poison dart frogs. They secrete neurotoxic alkaloid compounds known as batrachotoxins. These toxins are lipophilic, and can permeate unbroken skin. They bind to nerve cells, and basically "break" them - they open up the sodium channels in the cells (permanently depolarizing them) so that the nerves can no longer fire, and a flaccid paralysis ensues.

Bizarrely, the tetrodotoxin of the pufferfish may be a possible "treatment" for batrachotoxin-induced paralysis. Tetrodotoxin is non-competitive with batrachotoxin (meaning it wouldn't be trying to bind to the same part of the cell, and wouldn't have to remove the batrachotoxin first), and causes an extreme tetanic (stiff) paralysis, because it causes nerve cells to enter a state where they're permanently firing and can't stop.

Well, toxin or not, no deaths due to the pitohui have ever been recorded. The Papuan natives see pitohuis as "rubbish birds" because of their toxins, and avoid hunting them. Surely a few natives or explorers have died eating them in the past, but they aren't an active threat to anyone.

The birds of New Guinea and the adjacent Papuan Islands. R. Bowdler Sharpe and John Gould, 1875-1888.

Skulls of Naja tripudians (A, B, C) and Bungarus candidus (D, E)

The Bungarus candidus is commonly known as the Malayan krait, and the Naja tripudians (now Naja kaouthia) is the monocled cobra. Both have venoms with nearly 100% neurotoxic action and were used in Dr. Noguchi's research to compare against the hemotoxic venoms of other snakes.

Snake Venoms: An Investigation of Venomous Snakes with Special Reference to the Phenomena of their Venoms. Dr. Hideyo Noguchi, 1909.

Effects of the Crotalus adamanteus venom on mesentery of rabbit (top), and pectoralis of pigeon (bottom).

Many venomous snakes have hemotoxic venom, or a hemotoxic component within their venom. These toxins are able to break down red blood cells, disrupt clotting, and cause hemorrhaging due to the blood being thin enough to slip through capillary and tissue walls. Unlike a neurotoxic venom, which kills by paralyzing the diaphragm and suffocating the victim or prey, hemotoxic venom does not kill quickly. The internal bleeding and hemorrhaging of organs and major vessels is extremely painful.

When snakes kill with hemotoxins, they tend to follow their prey until it collapses, before attempting to eat it. However, the majority of the time, it turns out that the prey isn't dead yet. It's simply in shock and unable to continue - it would end up dying soon enough, but if the snake isn't too far behind it, the prey does get eaten alive. 

Snake Venoms: An Investigation of Venomous Snakes, with Special Reference to the Phenomena of Their Venoms. By Hideyo Noguchi M. D., 1909.

Musculature of the venom apparatus.

Most venomous snakes can change the muscle tension around their venom sacs when they strike. This regulates how much (and if) venom is injected into the victim. In some species, almost 60% of bites are "dry" - not injecting any venom.

Snake Venoms: An Investigation of Venomous Snakes, with Special Reference to the Phenomena of Their Venoms. By Hideyo Noguchi M. D., 1909.

The action of venom on the internal organs.

Snake Venoms: with special reference to the phenomena of their venoms. Hideyo Noguchi, 1903.

Skull bones, teeth, and fangs of two venomous snake species.

Erpétologie générale, ou, Histoire naturelle complète des reptiles. A. Duméril, 1834.