World’s Most Dangerous Insects

If you added up all the lives lost in all the wars fought in the twentieth century, that figure would come to about 108 million people. That’s a staggering number, but horrifyingly, it pales in comparison to the lives taken by a pocket-sized assassin.

It’s a creature responsible for the deaths of between 150 to 300 million people in the last century alone! And to this day, it causes over 600,000 more deaths every year! This is a creature so small you may not even notice it’s there, but you can’t escape its tell-tale, whining buzz.

That’s right, we're talking about mosquitoes. You may think these are just pesky blood-sucking flies, but these bugs are super spreaders of fatal diseases that have plagued humanity since the dawn of civilization! Let's explore the dangers of mosquito diseases and investigate some of the most dangerous insects in the world.

Mosquito

There are over 3500 species of mosquitoes on earth! From the super tiny species which are only 0.1 inches long, just a sliver of the size of your fingernail, to the other end of the scale, the jumbo-sized Elephant Mosquito. These giant mosquitoes are nearly a full inch long! That’s about the same size as a cent coin!

They get their name from their trunk-like mouths that double as hypodermic needles! But thankfully these over-sized mosquitoes don’t have a taste for human blood, rather they prefer the sugary nectar from flowers.

Technically, there are only 100 species of mosquitoes that we really need to worry about, as they have both a taste for human blood and an ability to spread fatal diseases. Number one on that list is a bug that has been described as the most dangerous creature on earth, the Anopheles gambiae mosquito.

It’s this vampiric bug that has the capacity to spread malaria, a parasitic infection that’s hosted in the liver, eventually infecting the body’s red blood cells, causing life threatening complications.

In 2020, there were an estimated 241 million cases of malaria, and an insane concentration of 95% of these cases occurred in Africa alone. Here, the hot climate allows the Anopheles mosquito to survive year-round, enabling them to constantly feed and infect millions of victims.

Without effective treatment, malaria can be deadly. In 2004 alone, it was the lead cause of nearly a million deaths! However, recent aid efforts to distribute insecticide-treated bed nets to rural communities have brought this staggering number down by more than a third in 2020.

The insecticide destroys the mosquitoes, while protecting those who sleep under the nets from getting bitten as mosquitoes are most active at night. Even though the mortality rate has come down, a death toll of over 600,000 people per year is still a horrifying statistic.

But how could one disease keep the grim reaper so busy? That’s because malaria has millions of tiny flying carriers, the female Anopheles mosquito. Weirdly, it’s only female mosquitoes that feast on blood as it’s full of the proteins required to produce their eggs. Meanwhile, male mosquitoes are happy to chill in the park and enjoy some sweet flower nectar.

This species has been around for over 46 million years, and has had millennia to master a perfect set of skills to hunt humans. In fact, a mosquito can detect the carbon dioxide you exhale on your breath from over 30 feet away!

From there it flies closer, picking up on the scent of your body odor. Once it’s close enough to detect your body heat, it lands and tastes your skin with sensors on its legs, until it finds the perfect place to bite.

From there it puckers up its proboscis, the mosquito’s mouth, which is a seriously nasty thing to see up close, because it acts like a sheath to six needle-like mouthparts. These two mouthparts are known as the maxillae; serrated structures like dinner knives, that literally saw through your flesh to the closest blood vessel.

Once a blood vessel is pierced, the mosquito uses its other mouthparts to spread the tissue apart where it then inserts a straw-like structure inside, slurping up your blood like the world’s worst milkshake.

The good news is that a female mosquito only ingests 0.01 milliliters of blood per meal. That’s literally a tiny drop in the ocean of your entire blood supply. You might think that, if a mosquito only drinks a tiny bit of your blood, it must be harmless; but it isn't.

Because mosquitoes operate by sip feeding, they don’t take all of their blood meal from one source. Rather they take a buffet of meals from multiple humans, and as a result rapidly spread disease!

The Anopheles mosquito that plagues Africa is so deadly because when it feeds on an individual infected with malaria, it also ingests the plasmodium parasites that cause the disease. When it buzzes off and bites another human, its saliva is injected into the wound as it feeds.

This is because its saliva is full of anticoagulants that prevent your blood clotting, but the plasmodium parasites previously ingested also come along for the ride, and so find their way into your body!

The mosquitoes themselves are totally unaffected, but for humans, the plasmodium parasites pass to the liver where they multiply rapidly and start invading the red blood cells produced there! Symptoms of the infection then arise, such as a feverish temperature, muscle pain, vomiting and diarrhea.

The loss of red blood cells can also cause anemia and jaundice, a condition where the skin turns yellow. If medical treatment isn’t sought quickly, it can be fatal! So fatal, it’s led to a chronically high mortality rate in central Africa, particularly, and sadly, among children under 5 years old.

Without a doubt, malaria is the most devastating illness spread by mosquitoes. But it isn’t the only one! In fact, there’s a whole list of other horrible diseases you can catch from one of their bites!

If you’re traveling through any tropical climates, watch out for Aedes Aegypti. This mosquito is the carrier for a whole range of diseases!

Starting with the mildest, dengue fever is a disease that can cause nausea, vomiting and a bad rash. It can be caught by people visiting Asia, Africa, the Caribbean or South America; basically, all the best tourist spots are likely to give you a Dengue fever souvenir!

But not to worry, as for most people the fever will pass within a week or so. However, 1 in 20 people can contract severe dengue, a disease that can result in shock, internal bleeding and even be fatal! But you’d be taking an even worse risk if you were bitten by an aedes or an anopheles mosquito carrying parasitic worms!

These parasites can surf through your blood stream until they reach the lymph system, resulting in Lymphatic Filariasis! This is a disease that affects over 120 million people worldwide, mainly across the sub-tropics of Asia, Africa, and the Western Pacific.

Most people are asymptomatic and never develop clinical symptoms. For others though, the disease can cause some ballooning results, literally! A small percentage of people will develop lymphedema, a massive swelling of fluid in the arms, legs, or for some super unlucky guys, the family jewels!

This giant swelling affects the function of the lymph system, making it difficult for the body to fight off germs and infections. This can also cause bacterial infections to occur in the skin, resulting in a thickening and hardening of the skin in a condition known as elephantiasis.

Overall, this is a disease that can lead to some real body horror, but it’s not nearly as shocking as the effects of a disease Aedes Aegypti mosquitoes can spread to pregnant women.

These mosquitoes can also act as carriers for the Zika virus, a disease that has left a devastating impact on a whole generation in Brazil. Between April 2015 and November 2016, Brazil was overrun by a colossal Zika epidemic, registering some 1.5 million cases! Zika is a virus that can cause symptoms such as a mild fever, a headache, and a rash.

Contracting Zika is typically not fatal for an adult, but if a pregnant woman were to become infected with Zika, then this could cause a birth defect known as microcephaly; a condition where a baby is born with an abnormally small head. And in Brazil’s epidemic, over 3,500 new-born babies were affected!

Sadly, this isn’t a condition that you can just grow out of. Rather, the children affected usually develop lifelong learning disabilities due to their reduced brain size. And Zika is still present in Brazil today, being transmitted by those damn mosquitoes!

Furthermore, the Aedes Aegypti mosquito is rapidly spreading across the globe! It’s recently colonized Madeira, southern parts of Russia and southern states of the US such as Florida, Georgia, even reaching as far as Texas! But on the bright side, mosquito populations in the US aren’t heavily infected, so outbreaks of the dengue virus have only been small and limited in area.

Ticks

You need to be careful walking through the long grass, or you could end up with a hitchhiker embedded in your flesh! While you might have thought spiders were the creepiest eight-legged bug, let me introduce you to the vilest member of the arachnid family: ticks.

With 900 tick species worldwide, we can divide these cursed bugs into two categories: hard bodied and soft bodied ticks.

Just as the name suggests, hard bodied ticks have a hard outer shell and take on a more spider-like appearance, while soft-bodied ticks lack this outer shell and take on an even more sinister appearance! Also, an adult tick is often smaller than the size of a sesame seed. So even if you keep your eyes peeled, it’d be difficult to spot one in the wild.

It’s this ability to go unnoticed that forms the tick’s key adaptation to ensure its survival. Ticks go through four simple life stages: they hatch from an egg, transition from a six-legged larva to an eight-legged nymph, and finally emerge as an adult tick. But in order to pass to the next phase of their life cycle, they must gorge themselves on blood.

To access this malicious meal, ticks will latch themselves onto a host. They do this through a process called “questing”. This is where a tick climbs to the edge of a blade of grass or a plant leaf and holds out their front legs, waiting for a warm-blooded animal or human to brush past that they can hook onto.

From there they crawl around your body until they find just the right spot to bite through your skin and feed on a vein.

Unlike mosquitoes, ticks take a long time to finish their dinner. Undisturbed, a nymph tick can stay attached for 3-4 days, while a female adult tick can stay latched onto your body for up to 10 days! And while mosquitoes are polite enough to use a straw, ticks are super messy eaters because they repeatedly regurgitate all the binged blood they’ve drunk back up.

A fully engorged tick will only have extracted half a milliliter of blood, but in doing so would have sucked up and regurgitated 15 milliliters of blood! After a tick has finished feeding, its body is engorged and is able to grow up to 5 times its original size. Check out the before and after shot below from a single 8 to 10 day feeding session!

But the sight of ticks isn’t the only nightmarish thing about them. Rather, throughout a tick’s lifetime they will jump from host to host, and in doing so will carry each host’s diseases along with them! When these ticks regurgitate, they aren’t just throwing back up your blood, but also infecting you with parasites they picked up from their previous host.

Ticks can even cross the species barrier, spreading diseases from animals to humans! Such as the black-legged tick, a tick that latches onto both deer and humans as hosts. In doing so, this tick can spread a bacteria known as borrelia burgdorferi, and cause an infection known as Lyme disease.

Does that condition ring a bell? It’s an illness many famous faces have received treatment for, like Justin Bieber and Bella Hadid! Because, being a predominantly tick-borne illness, it’s disturbingly widespread across the US.

Lyme disease is an illness that can cause a bad fever, headache, chills, and muscle pain. But is most commonly identified by the tell-tale red bull’s eye rash that shows up on the skin surrounding the tick bite. So, if you see a rash like the one in the image below on your body, you’ve probably been bitten by a tick without even realizing it!

But not to worry, as most of the time, Lyme disease can be treated with antibiotics. However, delayed treatment can result in a condition known as late Lyme disease that arises months after the tick bite. Which can cause problems with dizziness, nerve pain, painful joints, even facial palsy! A condition which causes loss of muscle tone in the face, leading to drooping on one side.

And deer ticks aren’t the only ones to watch out for! A single bite from a Lone Star Tick could make you a mandatory vegetarian! Lone Star Tick bites can transmit a sugar molecule known as alpha-gal into your body, causing alpha-gal syndrome. In some people, this can trigger an immune system reaction, resulting in a sudden severe allergy to red meat!

But don’t let tick-borne diseases put you off enjoying the great outdoors, as in general ticks need to be attached for 36 to 48 hours before they can transmit their diseases. So, as long as you check your clothing and carry out regular tick-checks on your body, you should be fine!

If you do find a tick on your person, use a pair of tweezers to gently pry it off. But never ever crush a tick! As doing so could cause it to inject all of its toxic parasites into your body.

Bed Bugs

This next creature really is the stuff of nightmares. If you’re ever in your bedroom and detect a strange rusty smell, you may want to flip the mattress over, because there’s a chance you’ll find thousands of brown dots that look like someone’s attacked your mattress with a sharpie.

And if those brown dots are accompanied by crusty translucent flakes, then I have bad news: you have bed bugs! Though it’s unlikely you’ll find the live bugs themselves, as they’re active at night and hide during the day.

And I hate to tell you, but those brown dots are actually their poop stains! These “fecal spottings” mainly consist of digested human blood. These nasty bedroom lurkers are munching on you during the night! This digested blood contains a large amount of iron, the source of that strange rusty smell.

Meanwhile, those crusty flakes are actually molted shell casings, as bed bugs molt their exoskeletons after transitioning between each of their 5-lifecycle stages; from an egg to a nymph and finally an adult bug.

An adult bed bug is smaller than the size of an apple seed, with their flat oval-brown bodies only reaching some 4 or 5mm long. And, as the name implies, bed bugs live out their whole lifecycle in the crevices of your mattress!

While you may have Oreos as a midnight snack, bed bugs like to feast on your blood! Not that you’d realize, as when bed bugs bite you, they release a small amount of anesthetic in their saliva. You’ll only find out you’ve been bitten the next morning when clusters of red swollen bite marks appear.

They typically invade your home after an overnight trip, by catching a ride from the outside world into your home in your clothing.

The good news is bed bugs don’t feed every single night, rather they can go several weeks without eating! But this can mean bed bugs are unwanted roommates for months without you noticing.

Surprisingly, bed bugs aren’t the worst bunk buddies to have; though more than 40 pathogens have been detected in bed bugs, there has been no conclusive evidence that they transmit any diseases to humans. So, the worst thing you’ll catch from bed bugs is an itchy rash!

Nevertheless, most of us certainly don’t want to have any sleepovers with these creepy bloodsuckers. So, if bedbugs make themselves at home in your house, then you better put out a new roommate listing for an exterminator!

Murder Hornet

Some say bigger is always better, but there’s at least one thing that definitely gets worse the bigger it gets, and that’s the flying terror of Southeast Asia; the horrifyingly nicknamed ‘Asian Murder Hornet’.

Typically, Eurasian hornets are 1-inch long, about the size of a paperclip. While across the globe, murder hornets dwarf their Eurasian cousins with Queen Giant Asian hornets measuring in at over 2 inches long, more than double their size!

The worker hornets serving under the queen are only slightly smaller, and while you may think 2 inches is not huge, keep in mind that as a hornet is scaled up, so is its stinger! A honeybee’s stinger is only 1/16th of an inch long, while a giant hornet’s stinger is a quarter of an inch long, and can puncture through a specially designed bee suit!

These monster hornets put these wicked stingers to use in insect warfare, as they get their nickname from their brutal reputation of wiping out bee colonies! Murder hornets can destroy over 30,000 worker bees in a colony invasion!

After the worker bees have been annihilated, the hornets then abduct the larvae and pupae, taking them back to their own nest to feed to their baby hornets.

Thankfully though murder hornets don’t typically sting humans, unless provoked to defend their hives. But if you do get on the bad side of a murder hornet, then you’re in for a hellish bout of pain! The sensation experienced by those unfortunate enough to have been stung first hand has been described as like being stabbed by a red-hot needle!

Unlike honeybees, whose serrated stingers get caught in the skin and pulled out, meaning they can only sting you once, hornets don’t have a serrated stinger. So, the stinger doesn’t get stuck in the skin, which means they can sting you dozens of times over!

But why is the sting they deliver so painful? It contains a toxic cocktail of chemicals designed purely to cause pain and swelling, as well as an additional component called mastoparan. Not found in bee venom, mastoparan can combine with other chemicals to break down blood and muscle cells.

In addition, the histamine in a hornet’s sting can trigger a fatal allergic reaction in 1.2-3.5% of the population! It’s so severe, that according to a 2007 study, murder hornets are linked to between 30-50 deaths every year in Japan alone. Most casualties are from anaphylactic shock or sudden cardiac arrest. This bug is really living up to the title of “murder” hornet after all!

Despite how lethal a murder hornet can be, honeybees are technically more venomous. It might seem counterintuitive but insect venom is measured by the LD50 scale; this is the quantity of venom necessary to be fatal to 50% of a test group of mice. The less venom required for a lethal dose, the more dangerous the substance.

A honeybee’s venom has an LD50 of 2.8 milligrams per kilogram, while a giant hornet’s venom has an LD50 of 4.1 milligrams per kilogram. So, hornets must inject a far larger dose of venom in their stings than honeybees in order to overpower their victims. But to make up for this, hornets can sting repeatedly, delivering up to 10 times more venom than honeybees!

So, to reach a life-threatening toxic dose, a person would only need to be stung by a couple hundred hornets vs around 1000 honeybees. And unfortunately, this species is now invasive to the United States! Everything gets bigger in the US, but giant hornets are one thing that should have stayed extra small!

Blister Beetle

If you ever go for a roll in the hay, literally, you might want to have a quick look at what exactly is in that hay pile first! Because other than startling a few horses, you may also end up crushing a blister beetle!

Just as the name implies, these toxic bugs produce cantharidin, a nasty chemical that can cause the skin to erupt in huge blisters! But not only that, if someone were to accidentally consume a beetle, the unleashed cantharidin could destroy the lining of the gastrointestinal tract!

The real danger these biohazard beetles pose is to farm animals, as blister beetles are attracted to alfalfa hay. It’s a hay that is commonly used for cattle and horses as it’s a great source of protein and fiber.

If the beetles are ground up in the hay after it’s processed, then this can contaminate the hay fibers with toxic cantharidin. And ingesting as few as one or two blister beetles can be fatal, even to an animal as big as a horse! Blister beetles aren’t a bug to foal around with!

If you were amazed at the most dangerous insects in the world, you might want to read our article about dangerous bugs and what to do if they attack you. Thanks for reading!