While human involvement is often disastrous for many species of animals, it seems like nothing we can do will stop some insects from thriving. In fact, it seems likely that many of the creepy crawlies that we try to eliminate will end up outliving the human race entirely! They may walk on more than two legs, but some of these insects are more likely than we are to be the last living thing standing someday.
Usually when we think of insects that will outlive the human species, cockroaches are the first that leap to mind. These skittering little pests are an unwelcome sight in any home, and getting rid of them can certainly seem to be an uphill battle. However, many household pests can pose a challenge to eradicate, but what makes cockroaches stand up? To start with, they are able to adapt to changes at a breakneck speed. In the 1980s, exterminators began mixing poison with a sugary sweet bait in order to eliminate roaches, and it proved very effective. Until suddenly it didn’t. In just a few generations, roaches were able to evolve in order to find glucose bitter tasting, meaning that they were no longer ingesting the poison. And speaking of reproduction, a female cockroaches anthem might as well be “No Boyfriend, no problem,” because they don’t need males in order to breed. That’s right, when the going gets tough, the lady roaches get along just fine on their own. In the event that humans no longer exist because of nuclear war, cockroaches have been shown to be quite resistant to radiation. In a study conducted by myth busters, out of thousands of roaches, 30% of them were able to survive Hiroshima level radioactive rays.
Another insect that we frequently considered to be an unwelcome guest is the wasp. One particular wasp family, the braconid is a parasitoid. While we know that parasites spend time mooching off of a host, parasitoids take it a step further and actually spend most of their lives attached to a host. This insect can trace its roots all the way back to the Cretaceous period, and it shows no signs of going anywhere anytime soon. In fact, they appear to be very resistant to radiation that would be fatal to a human. A dose of 400 to 1,000 rads is lethal to humans, however to take down a braconid wasp, you’ll need about 180,000 rads. And when exposed to a non-lethal dose, females are actually able to maintain their fertility. When they sting a host insect, they infect them with a virus that suppresses the immune system and allows their young to grow inside the hosts undetected. They can even create a chemical change in the brain of its host, causing them to live out the remainder of their lives protecting the wasps. Needless to say, this isn’t exactly healthy for the host insect, but it greatly increases the survival rate of the wasps.
When they’re invading your picnic or your pantry, you may think that all ants are the same. However, there are actually over 12,000 species of ants. Why do we think that they might outlive the human race? Well, they’ve already survived one mass extinction what’s one more? While we aren’t sure if it was a massive meteor, or what exactly happened, we know that an event occurred that heralded the fall of the dinosaurs. Known as the Cretaceous Paleogene extinction event, or the Cretaceous tertiary extinction event, it occurred about 65 million years ago. While this brought an end to many species, ants not only survived but they thrived as well. And developed into many of the different species we see today, an expanded worldwide. It’s so impressive that entomologist Ted Schultz called it “Arguably the greatest success story in the history of terrestrial Meta Zoa.” What the exception of Antarctica, the arctic, and a handful of islands, native or invasive ant species can be found on every piece of land on the planet. And some species of fungus farming ants have even been caught cooperating with each other in order to survive. If other ant species work together, their odds of survival would increase even further.
When faced with adversity that would cause extinction of another species, locusts are not only able to survive, but to thrive. You know how some people just seem to do better under pressure? the locust functions the same way. They’re members of the grasshopper family, and while we often only hear about them when their massive swarms impact our food supply, they’re actually solitary by nature. What causes plagues of locusts is hardship. When plants begin growing after a drought, the serotonin in their brains triggers a dramatic set of changes. They become migratory, they breed quickly, and they band together with their fellow locusts. Humans have to maintain incredible diligence to prevent locusts from swarming because if they get the chance, they can be devastating. One plague that occurred in Africa, the Middle East, and Asia from 1966 to 1969 saw the number of locusts increasing from 2 billion to 30 billion over just two generations! If locusts become resistant to the pesticides used to control them, or humans aren’t vigilant enough, it’s not hard to imagine that locusts might not only outlive us, but contribute to our extinction by ravenously devouring our food supplies.
You may have heard that you can’t hide from your problems, but try telling that to the Cicada. Even if you’ve never seen a Cicada, you’ve probably heard their incredibly loud songs. The males cause their tymbals, a corrugated exoskeletal structure, to vibrate, which produces loud noises. While adults live in trees, feeding on sap and laying their eggs in the crevices of the bark, Cicadas spend most of their lives underground. When the eggs hatch, the Cicadas fall from the tree and dig into the ground to feed on roots. Cicadas can spend 2 to 17 years underground before they’re finally ready to emerge this means that they can miss out on a lot of unpleasant things that us humans have to deal with on the surface. They can even cause their predators to potentially starve by simply not being available. Then when they emerge in huge numbers, they’re able to overtake any remaining predators. In addition, Cicadas are unusually resistant to bacteria. Their four wings are super hydrophobic, meaning that it repels water. It was once thought that the tiny waxy cones that causes this also repelled bacteria, but we now know that the bacterial membranes are torn apart by the spikes. This makes their wings the first known biomaterial capable of destroying bacteria. We don’t mean to bug you.
When it comes to difficult to get rid of pets, Bed Bugs are a human’s worst nightmare. For a while in the 1940s, it seemed like humans were winning the war against Bed Bugs when we began using DDT to get rid of them. When it appeared that they had become eradicated, they suddenly came back with a vengeance. 95% of pet control companies nationwide report treating a Bed Bug infestation in the past year. Just one decade ago, only 22% reported treating one in the past year. Bed Bugs have evolved to be resistant to pesticides. They’ve developed thicker, denser exoskeletons, called cuticles, that actually repel the pesticides in pesticides. In addition to this, Bed Bugs also have incredibly fast metabolisms, and are able to metabolize toxins rendering them harmless. One common poison, pyrethroids work by binding to and blocking sodium channels, which cause the bugs to become paralyzed. However, 88% of Bed Bugs have mutated to block these pyrethroids. And Bed Bugs have a long history of evolving to meet changing environments. They once fed on bats, but a whole new species evolved in order to prey on humans. The ones that plagued us have longer, thinner legs because they don’t need to cling to bats hanging upside down from caves.
Cockroaches are often lauded for their ability to withstand massive doses of radiation that would be fatal to humans, but there’s actually an insect out there that can outlive roaches when exposed to radiation. Meet the Flour Beetle! These common household pests attack and infest stores of Flour and grain. Like the locusts, these insects can be incredibly destructive to human, and they’re not exactly easy to get rid of. They are known to hide in cracks and crevices, and even after they pass away their bodies can encourage mold to grow. These destructive beetles can survive larger doses of radiation than we can. Earlier in our article we mentioned that during a Mythbusters test, 30% of cockroaches managed to survive Hiroshima Esque levels of radiation. At the 10,000 rads they were hit with, 94% of flour beetles survived. And when the team cranked up the radiation to 100,000 rads, 10% of flour beetles lived while all the cockroaches were wiped out. For reference, as puny humans can’t withstand over 1,000 rads.
If you don’t look carefully enough, you might not notice a katydid at first glance because of their close resemblance to a leaf! Also known as bush crickets, these insects are masters of blending, and live in a variety of different habitats. When found in less moist or more stressful habitats, katydids tend to be smaller which isn’t always a bad thing when it comes to survival. In fact, because of their small size, they are more agile, develop faster, and have lower nutritional needs. In a situation where food supplies are scarce and plants are suffering, the katydid will have a huge advantage over humans when it comes to getting enough nutrients to survive. Some katydids even come equipped with spines all over their bodies. These help confine their prey and create a temporary cage over the insect’s mouth. While they might look intimidating, they’re actually not sharp, which is why they’re used to encase their enemies rather than impale them. These insects even pretend to be asleep in order to make predators think that they are leaves, or that they passed away.
We tend to feel itchy just talking about these insects, but fleas have been around since the early cretaceous and we don’t anticipate them going anywhere anytime soon. Their legs are adapted for jumping, and this enables them to leap about 50 times their body length. This means that they are the second longest jumping insect, with the first place spot being reserved for the Frog hopper. In addition to jumping up to 13 inches horizontally, it can leap 7 inches into the air. Fleas are known for spreading disease, perhaps the most famous of which is the Black Plague which may sound familiar as it was one of the most devastating pandemics we’ve ever experienced. Their bodies are simple and compact, but are meant to resist massive amounts of pressure. It’s believed that this evolved in order to help them avoid being scratched off by unwilling hosts. Like many other insects on our list, it seems likely that fleas might not only outlive the human race, but may play a hand in our destruction as well. Currently, they have a huge economic impact on us, as people in the United States alone spend $2.8 billion dollars per year on vet bills related to fleas, and an additional $1.6 billion is spent paying groomers to deal with them.
Cereal Leaf Beetle
Much like Locusts and the Flour Beetle, the Cereal Leaf Beetle is a serious threat to crops, and they get started destroying crops early too. Their larvae are the greatest threat to crops, eating the superficial layer of leaves which limit the plant’s ability to perform photosynthesis. Fields where they have stuck appear “Frosted” in appearance because of the resulting lack of coloration. In addition to being destructive, these larvae are just plain unpleasant. Although that could be said about many young creatures, including humans, these larvae are known to smear excrement on their yellow or white bodies in order to camouflage themselves. Yikes! As climate change causes milder weather, the Cereal Leaf Beetle is able to expand its habitat into areas where it would normally be deterred by the cold. These insects are native to Europe and Asia, but is becoming increasingly common elsewhere. Regarding eradicating them, it’s harder than you might think. Farmers must time the application of pesticides just right, or the eggs will survive, and even thrive because predatory insects have been wiped out. Although there has been success managing these populations by using parasitic wasps. So perhaps one resilient insect might take care of a major pest problem for us.