These are the Most VENOMOUS Insects in the US

If you've ever been stung by a bee, you probably know that many insects pack a venomous punch. But what if I told you there's actually tons of venomous insects, many of which are living closer to you than you'd think? From a venomous fly to caterpillars that can land you in the hospital, the world of venomous insects is insane. And there's so many of them that it's hard to definitively say which species are even the most venomous of them all. But today I'm going to show you five insects that are the most venomous of their groups, starting with one that I guarantee is in your backyard right now. The robber flies cover the entire U.S., and while they look kind of like a cross between a dragonfly and a bee, they're actually not close related to either of them. Robber flies are from the family Acillidae, which is in the exact same insect order as the annoying house flies and mosquitoes that you see on a daily basis. While there are some weird endemic species found in only really select special habitats, there are over 7,000 species of robber fly in the world, and odds are there are probably more than a few living right near you right now. These insects are diurnal active hunters, and just like the dragonflies they look like, they hunt in the air, snatching their prey mid-flight. And the way they kill their prey is with, you guessed it, venom. Using their piercing mouthparts, these flies deliver a cocktail of neurotoxins, paralyzing the insects they eat in seconds. Because they don't eat solid food, their venom also dissolves their prey from the inside, and they slurp that juice up like a milkshake. And since they're venomous, you're probably wondering, well, can they bite? And the answer is yes, and it's very painful. There's a lot of variety in the sizes of robber flies, but the bigger ones definitely pack a punch. But since they're not parasitic like horseflies or deerflies, they're not really going to seek you out to bite you. They're pretty much only biting humans when they are actively being picked up. So unless you're researching robber flies for something and you're handling them with your bare hands, I don't think there's any scenario where you'd be getting bitten by a robber fly. For the most part, these insects are happy to actually eat many pest insects that might be in your backyard. So if you come across a robber fly, just take a minute to appreciate a fleeting encounter with a really cool natural predator. For the most part, venomous insects are using their venom to hunt other insects. It turns out that if you eat insects as your main source of food and you happen to be an insect yourself, venom is actually pretty useful. And that is also the case for the wheel bug. The wheel bug is the largest assassin bug in North America, and they get their name from that big spinosaurus-like crest on their thorax. These things are wild looking, and they're more common than you'd think. They spend most of their time lurking in vegetation, using that drab gray coloring as camouflage while they wait for other insects to come by. If you take one look at these insects, you can already see that really scary looking hooked beak on their head. Yeah, that's the business end of the wheel bug. They're using that rostrum to deliver a powerful cocktail of destructive venom into their prey. The venom of the wheel bug is cytotoxic, which means it attacks the cells of its victims. When I ran lab tests on this venom with human blood, it actually triggered all of the cells in the sample to spontaneously die. And what's happening when this venom gets inside its prey is it's killing tissue, bursting cells, and destroying proteins, turning their insect kills into insect slushies, which the wheel bug slurps out using that same rostrum as a straw. To say the wheel bug bite is unpleasant honestly does a disservice to anybody in the comments who has been bitten by a wheel bug. It's a pretty bad bite. This insect bite is so painful, it's actually dethroned pretty much most if not all of our native wasps. It may even be worse than the tarantula hawk. Because that venom is cytotoxic, it's going to destroy a lot of the tissue where it bites as well, causing swelling, pain, and oftentimes even scarring. These assassin bugs are no joke. Now, there is a common misconception that the wheel bug transmits Chagas disease, and while that parasite is transmitted by an assassin bug, wheel bugs do not carry it. So while a wheel bug bite is very painful, unless you happen to be allergic to the venom, it's not life-threatening. The nice thing about these insects is they are very mild mannered, and like other ambush predators, they actually rely on their camouflage to keep them safe. These guys prefer to stay hidden in the plants, waiting for insects to come to them. They have no interest in picking fights with humans. This next insect actually does tend to bite people a lot more often. It's actually where it got its name, the toe biter. These giant water bugs are huge. They're actually the largest true bugs in the world, and they are ferocious predators in the aquatic ecosystems they call home. They sit extremely still, clinging with their back legs to vegetation, and they look just like fallen leaves. But here's the kicker. Where assassin bugs and robber flies are primarily hunting other insects, the giant water bug is hunting fish and amphibians, and even some of the larger species abroad have been known to take down baby turtles and snakes. So this means that their venom is adapted to killing vertebrates. Now, normally I like to rank venom potency in terms of actual measured lethal dose, but with insect venoms, we've studied so little of them that there isn't any data on how toxic the venom of the toe biter is versus the assassin bug or pretty much anything else on this list. But I rank the toe biter higher than the assassin bug because of the fact that its venom does kill vertebrates. And anyone who's been bitten by a toe biter knows that it is quite unpleasant. It is a sharp, powerful sting that causes lots of swelling, inflammation, and potentially scarring, just like the wheel bug. The only problem is I don't know anybody who's been bitten by both a wheel bug and a giant water bug, so I don't know which one is necessarily more painful. What we do know is their venom is highly cytotoxic. Like the assassin bug, they can't eat solid food, so they're liquefying their prey while it is still alive and drinking the liquefied innards out with their straw-like mouthparts. If you are a fish or a tadpole, the bite of the toe biter is terrifying. But fortunately, they're not actually aggressive. See, bites from these insects happen when people are waiting barefoot in the ponds and creeks they call home. When you accidentally step on one of these insects, they're going to bite in self-defense and it is very, very painful. Because people are usually getting bitten while they're waiting, it's actually where these insects got the nickname toe biter, because people were actually physically stepping on these insects and the giant water bug would latch right onto their toes in the water. One of my favorite things about these insects is they can fly. So not only are they these huge venomous predators of aquatic ecosystems, but they can also turn up at your porch light. And that's where most people are usually finding these bugs. They are big, they look like aliens, and they might be a little bit scary, but rest assured, the insects get even more scary from here. This insect is actually the only one on this list that is regularly known to put people in the hospital, even if they aren't allergic. And while this segment is going to focus on the flannel moth caterpillar or the tree asp, I'd like you to go to bed knowing tonight that there are a lot more venomous caterpillars than just the flannel moth. Many of the silk moth caterpillars have venomous spines and there's even debate on whether the saddleback caterpillar is more venomous than the flannel moth. The thing about being a caterpillar is you're slow-moving, you're super juicy, and have been eating plants your entire life. Since plants have a lot of sugar, as far as many of your predators are concerned, you are basically just a big wiggling piece of candy. Tons and tons of energy and nutrients packed into every single caterpillar. So in order to survive, many of them have evolved a lot of really cunning defenses. And in the case of the flannel moth, it is a gnarly, gnarly venom. Unlike the biting mouth parts of the robber flies, assassin bugs, and toe biters, and the stingers of the bees, ants, and wasps, these guys actually have a whole completely unique venom delivery method. Those hairs that cover their whole body hide venomous spines. This is going to be an oversimplification, but you can kind of think of their spines as like fiberglass particles that are lined with the stinging cells that jellyfish have. Basically when touched, pieces of hair break off, and when those pieces break, they spill venom into the skin of whatever touched them. And this is reported to be one of the most painful, not just stings, but envenomations of any kind in the entire animal kingdom. You're going to have the localized pain, the rashes, the blisters, the swelling, but that pain radiates out from where you get stung. And even in healthy adults who are not allergic to the venom, the effects can go systemic. We're talking headaches, nausea, vomiting, sweating, fever, chest pains. You can feel like you are dying when you are stung by this caterpillar. It is no joke. It is nothing to play around with. It's honestly kind of frightening. And this is one of those weird times where the venom is entirely for defense too. With very, very, very few exceptions, caterpillars aren't eating other insects. But there are a lot of things that would like to eat a caterpillar. So if you have one of the gnarliest venoms in the insect world, you can rest assured that a lot of your would-be predators will probably look for something a little bit easier to take down before they come chasing after you. Because these caterpillars aren't super vibrantly colored, and because they're pretty widespread across their range, stings happen. And all it takes is just accidentally placing your hand on one on a tree branch, or even having one fall out of a tree on you, and you're gonna be in a world of pain. So if you live in ASP country, the only thing I can really tell you is be careful. Now surely you're wondering what could possibly be worse than a caterpillar that can land me in the hospital. And truthfully, I would say probably nothing. There's so little work done on the toxicity of insect venoms that as an armchair entomologist, I would say the flannel moth caterpillar is about as bad as it gets when it comes to insect venoms. But we actually do have a measured lethal dose for another insect that is considered to be not just the most venomous insect in the U.S., but the entire world. And that is the Maricopa harvester ant. Now to put it in perspective, yes, one ant is not very large, and one sting, while decently painful for such a small insect, is not that bad. Their venom is impressively toxic. It's on par with many cobras, and is actually more toxic than any of the venomous snakes found in the U.S. Yeah, these guys are gnarly. Found throughout the southwest U.S., the Maricopa harvester ant is a small orange ant, and they get their name from the way they actually harvest plant material from around their vicinity. In the deserts they call home, they're actually a really important part of the ecosystem because surface conditions are so dry that plant material just dries up, shrivels, and doesn't really biodegrade back into the environment. But under the ground, meters below the surface where their food stores are, it's much more damp, and these nutrients can actually get back into the environment more easily. So in many ways, the harvester ant is a vital part of what keeps the desert ecosystem alive. These ants do occasionally take insect prey, but they're primarily herbivorous. That venom, that sting, is to help keep potential invaders at bay. Their venom is very toxic, but one ant doesn't contain very much venom at all. But a mature colony could have thousands of workers, and if you enrage an entire colony and get swarmed, you could be in serious trouble. For somebody my size, it takes about 600 stings to put you in the grave. That sounds like a lot, but if you have hundreds of ants crawling up your legs, 600 is a lot less than you'd think. Even just one sting can have systemic effects, causing muscle aches, spasms, and even fatigue for days on end. I've seen harvester ant stings compared to mild black widow bites. So even though it takes 600 to kill someone my size, it's possible that because of how toxic that venom is, that it may actually take less for my body to go into shock and then die. So harvester ants are definitely something you want to respect and keep your distance from. Fortunately, unlike fire ants, they are native and they aren't aggressive. They're not going to actively seek you out. They're not going to sting without warning. In fact, because of course I did, I tried to test the sting, and many of them wouldn't even attempt to sting. You pretty much need to be an active threat to their colony for them to waste that precious venom on you. And because they're so important to the actual ecosystem they come from, I don't think of them as a venomous insect to fear, but something that's actually really, really cool and unique about the insect world here in the U.S. And that's part of why I love insects so much. At their small size, they face so many different challenges. It's forced them into all kinds of creative adaptations from powerful armor, cunning camouflage, and these toxic venoms. But just like there's lots of venomous insects that are injecting their toxins, there are tons of poisonous insects too, where if you eat them, you're in trouble. And just like the venomous ones, I bet there are some poisonous insects living in your backyard right now. If you want to learn about the most poisonous insects in the U.S., check out this video right here. Hope to see you there, but until next time, don't forget to get outside and find your own adventure.