29.1k readers

The Craziest Parasite Life Cycles

Updated December 11, 2017 29.1k views12 items
Webster's defines parasites as "the scariest things on earth, that threaten our very way of life." Or at least that's how they should define them. Parasites are utterly frightening and the effect they have on their hosts does not tend to be pleasant. Some of them out there are truly terrifying and the little buggers live absolute crazy life cycles. Check out the list below for some of the craziest parasites and their odd life cycles so you know exactly what to avoid. 
  • Frog-Mutating Flatworms

    Imagine if you started growing random, totally mutated back legs as the result of some renegade parasite? What would you think? Hopefully you never have to find out because as of now, the frog-mutating flatworms only affect amphibians. These parasitic larvae cause limb development to go horribly wrong within frogs, leaving them with deformed legs that severely limit their hop. Why would the parasite do this? Simple. By making the frog unable to hop properly, it makes it easier for birds to snatch them up and eat them. Then, once the frog is dissolved, the bird makes droppings all over that contain more of the parasite. 
  • The "Some Like It Hot" Tapeworm

    Photo: Ron Offermans / via Wikipedia
    The life cycle for the Schistocephalus solidus is a long and complicated one. It infects birds that live by the water and it reproduces in the host's intestines until eggs drop into the water along with the bird's droppings. Once there, the eggs hatch into larvae and infect very small crustaceans called copepods. Those are eaten by fish called sticklebacks, which are then eaten by birds again, where the whole cycle repeats. What makes this parasite's cycle crazy is how it affects the sticklebacks. The parasite needs to survive a long time in the fish so it can grow, so it manipulates the stickleback to swim to warmer waters and stay there. The parasite then can grow heavier than the fish itself, making for one awkward arrangement. 
  • Photo: Metaweb (FB) / Public domain
    The life cycle of the filiarial worm isn't the most insane thing ever, but it does manage to affect humans in horrible ways as it casually destroys us from within. The worms start off in our bodies and as they mature, they mate. The female then proceeds to release thousands of tiny parasites into our bodies, which head straight toward our lymph and blood systems. Mosquitoes come and drink our delicious blood, pick up the parasites, then transfer them to another host when they bite someone else and the whole thing repeats. Nothing too extravagant, but when the parasites are in our bodies, they can cause severe cases of elephantiasis and blindness, among other things.
  • Emerald Cockroach Wasp

    Photo: Metaweb (FB) / Public domain
    It's probably the only parasite that can make us feel sorry for cockroaches. This is a bizarre type of parasite called an entomophagous parasite, which means it's an insect that is parasitic on other insects. Once the emerald cockroach wasp mates, it finds a certain species of cockroach and stings it twice. In what can only be described as "overkill," the first sting injects a venom that paralyzes the bug, and the second one shuts down the part of the brain that makes it want to escape. The wasp then trims the cockroach's antennae and lures it back to its burrow using the antennae as a leash. As if things couldn't get any worse, the wasp then lays an egg on the cockroach's stomach and buries it. Once the egg hatches, the cute baby wasp eats its way through the bug's stomach and grows into a cocoon. It eventually gets strong enough to emerge on its own and do the same thing all over again.