The Wasp That Brainwashed the Caterpillar Read online

  PENGUIN BOOKS

  THE WASP THAT BRAINWASHED THE CATERPILLAR

  Matt Simon is a science writer at Wired magazine, where he specializes in zoology, particularly of the bizarre variety. He is one of just a handful of humans to witness the fabled mating ritual of the axolotl salamander, as is detailed in this here book that he hopes you enjoy.

  PENGUIN BOOKS

  An imprint of Penguin Random House LLC

  375 Hudson Street

  New York, New York 10014

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  Copyright © 2016 by Matthew Simon

  Illustrations copyright © 2016 by Vladimir Stankovic

  Penguin supports copyright. Copyright fuels creativity, encourages diverse voices, promotes free speech, and creates a vibrant culture. Thank you for buying an authorized edition of this book and for complying with copyright laws by not reproducing, scanning, or distributing any part of it in any form without permission. You are supporting writers and allowing Penguin to continue to publish books for every reader.

  LIBRARY OF CONGRESS CATALOGING-IN-PUBLICATION DATA

  Names: Simon, Matt.

  Title: The wasp that brainwashed the caterpillar : evolution’s most unbelievable solutions to life’s biggest problems / Matt Simon.

  Description: New York, New York : Penguin Books, 2016. | Includes bibliographical references.

  Identifiers: LCCN 2016001823 (print) | LCCN 2016029575 (ebook) | ISBN 780143128687 | ISBN 9780698411258

  Subjects: LCSH: Animals—Adaptation. | Predation (Biology) | Parasitism.

  Classification: LCC QH546 .S58 2016 (print) | LCC QH546 (ebook) | DDC 578.4/7—dc23

  LC record available at https://lccn.loc.gov/2016001823

  While the author has made every effort to provide accurate telephone numbers, Internet addresses, and other contact information at the time of publication, neither the publisher nor the author assumes any responsibility for errors or for changes that occur after publication. Further, the publisher does not have any control over and does not assume any responsibility for author or third-party Web sites or their content.

  Cover design: Roseanne Serra

  Cover illustration: Vladimir Stankovic

  Version_1

  For those earthworms I put on leaves and raced down flooded gutters when I was a kid. That wasn’t funny. I was a jerk, and I’m sorry.

  Oh, and my family. Them too. Not that I put them on leaves and raced them down flooded gutters. I mean I’m also dedicating the book to them.

  Contents

  About the Author

  Title Page

  Copyright

  Dedication

  Introduction

  CHAPTER 1:

  You Absolutely Must Get Laid

  Antechinus

  Anglerfish

  Flatworm

  Mustache Toad

  Toadfish

  CHAPTER 2:

  You Can’t Find a Babysitter

  Ant-Decapitating Fly

  Glyptapanteles Wasp

  Asp Caterpillar

  Ocean Sunfish

  Lowland Streaked Tenrec

  Surinam Toad

  CHAPTER 3:

  You Need a Place to Crash

  Pearlfish

  Tongue-Eating Isopod

  Pistol Shrimp

  Sociable Weaver

  Hero Ant

  CHAPTER 4:

  You Live in a Crummy Neighborhood

  Water Bear

  Diving Bell Spider

  Zombie Ant

  Pink Fairy Armadillo

  Naked Mole Rat

  CHAPTER 5:

  Turns Out Getting Eaten Is Bad for Survival

  Hagfish

  Axolotl

  Cuttlefish

  Satanic Leaf-Tailed Gecko

  Pangolin

  Crested Rat

  CHAPTER 6:

  It Turns Out Not Eating Is Also Bad for Survival

  Giant African Land Snail

  Aye-Aye

  Mantis Shrimp

  Bone-Eating Worm

  Tiger Beetle

  CHAPTER 7:

  You Can’t Let Them Get Away That Easily, Can You?

  Bolas Spider

  Velvet Worm

  Geography Cone Snail

  Lamprey

  Assassin Bug

  A Few Parting Words

  Acknowledgments

  Bibliography

  Introduction

  We need to talk about the wasps. I don’t mean the little yellow and black things that menaced your childhood summers. Those are lambs, quite frankly. No, I mean, in no particular order: the one with a sting so powerful a scientist who has experienced it recommends lying down and screaming until the pain subsides, lest you run around in a panic and hurt yourself; the one that stings a cockroach in its brain and drags the zombie into a den, where the wasp’s larva devours it alive; the one that opts instead to inject caterpillars with its young, which consume the hapless crawler alive from the inside out. Wasps are unparalleled in their ability to inflict suffering on other creatures, insects so cruel that Charles Darwin insisted a beneficent creator could never have thought them up.

  But the thing is, in the animal kingdom, life sucks and then you die—as the saying goes. And out there, it’s easy to die immediately. It’s been that way for billions of years. For pretty much every creature (save humans), there’s no slipping away peacefully in a comfy deathbed, because at any given moment some animal is trying to pull its head out of another animal’s mouth. And I can guarantee you that something somewhere has a wasp larva consuming it from the inside out. Hell, a tree probably just fell on some kind of critter. A tree.

  Nature is indifferent to death and suffering, and that’s unsettling to us humans. We don’t like thinking about an animal trying to pull its head out of another animal’s mouth. There’s no decency in that, for Pete’s sake. But really, it’s more than decent. It’s beautiful. The predators and prey that grace this planet are the culmination of millennia after millennia of glorious evolution. From a single, ultrasimple organism all those years ago an explosion of life has radiated across the planet, and that life doesn’t, well, always get along. And creatures don’t have to worry about just each other: harsh climates and floods and tornadoes and asteroids are also cause for some concern.

  Simply put, animals got problems. But at its core, evolution is the most majestic problem-solving force on planet Earth. Where it gets complicated is that it also creates all the problems. So things in the animal kingdom get a bit . . . involved.

  Let’s take, as an example, the plight of the zombie ant. It begins life as a normal ant in the rain forests of South America, foraging with its comrades along the colony’s trails when, unbeknownst to the ant, it picks up a passenger: the spore of a fungus. Sticking to the ant’s cuticle, the spore works its way into the host’s body—and its mind. Here it releases chemicals that hijack the ant’s brain, ordering it away from the colony and onto the underside of a leaf, always at a specific time of day at a specific height off the ground where the fungus can best grow. The parasite commands the ant to bite onto the vein of the leaf, then kills it and bursts out of the back of its head as a stalk to shower spores on the colony shuffling below. And thus the cycle repeats itself.

  First of all, I didn’t make that all up (we’ll see the zombie ant in all its glory in chapter 4). And second, it’s an unsettling illustration of nature creating and solving its own problems. At
the base of it, to disperse its spores, a fungus would do well to have wind, which is lacking in the thick rain forest. So over millennia the fungus evolved a solution—use ants as vehicles. Yet the ants have their own solution to this problem: They instinctually grab individuals that look sick and drag them out of the colony and into a mass grave. But, alas, the fungus in turn has a solution to this problem: By manipulating the zombified ant out of the colony, it can avoid discovery. Thus one side evolves an offense and the other a defense, year after year, millennia after millennia. Push and pull, push and pull.

  As if organisms didn’t have enough to worry about with predators and even malicious fungi, the push and pull of problem and solution can bring conflict even between the sexes of a given species. You see, males and females don’t have the same interests when it comes to sex. Males tend to take notice of anything that moves, while females have to be choosier. And then, randy fellas can come in conflict with other randy fellas. The males of one species of toad, for instance, have gone so far as to develop weaponized mustaches to battle each other for the right to mate. Even hermaphroditic species like some varieties of flatworm will clash among themselves, for when two individuals come together to mate, neither wants to get pregnant. Their solution? Penis fencing, obviously (coming up in the very first chapter, because I assume you’re intrigued).

  So what gives with all the conflict in the animal kingdom? Well, it’s the system, man, the system. Specifically, Charles Darwin’s idea of natural selection. Organisms must compete for food and water and often shelter, both with other species and with their own kind, and these individuals of course vary, due to errors during DNA replication and the unique way parents’ genes mix for each offspring. Because there isn’t always enough food to go around, not everyone is going to make it. If the ones that do make it have lucky genetics that help them win those resources, they can breed and pass down the primo genes, thus continuing the family line.

  And food is just part of it. Those best equipped to escape predators, perhaps because they’re that much faster than their peers, survive to pass down their genes. Those that can better tough it out in a harsh environment survive to pass down their genes. And those that are particularly impressive to the opposite sex, perhaps with exceptional feathers or dancing skills, win the right to pass down their genes. Conflict is everywhere, between predator and prey, brother and sister, sexed-up male and sexed-up female. A species may gain an edge, but any sort of edge is answered.

  Weakness in the animal kingdom is dealt with accordingly, as creatures at times literally keep each other on their toes. Which is all to say that over the billions of years of life on Earth, evolution has created many a problem but also found many a solution. Push and pull, push and pull. And more often than not, things get really creative and really weird. This book is a journey through the strangest of the strange—a bestiary of sorts. And not a single one of these animals will die at the hands of a tree. A murderous fungus, maybe, but never a tree. You have my word on that.

  CHAPTER 1

  You Absolutely Must Get Laid

  In Which Marsupials Hump Until They Go Blind and Die and Flatworms Stab Each Other with Their Penises

  You’re fond of sex, and that’s okay. Everyone is—everything is—because living beings have to be. It’s why we’re on this planet: to pass down our genes to the next generation. You’ve got your tired pickup lines or that thing you do with your hair, or maybe, if you’re feeling bold, both at the same time. And that’s nothing to be ashamed of, because sex in the animal kingdom is far more ridiculous than anything you could possibly dream up. I’d guess, for instance, that you’ve never had so much sex that you died. Just a guess.

  Antechinus

  PROBLEM: The only reason any life is on this planet is to make babies. That turns out to be a lot of pressure.

  SOLUTION: The males of a marsupial called antechinus mate with every lady they can find for three straight weeks until their hair falls out and they bleed internally and go blind and die, plus other bad things.

  I know the meaning of life. I realize that’s a rather bold thing to declare, but I really do know it. It is as follows.

  Make a lot of whoopee. A lot of whoopee.

  For the 3.8-billion-year history of life before we humans showed up and got all philosophical about our existence, critters on this planet had one goal and one goal only—to reproduce. Their secondary goals: eating enough to fuel the drive and not getting eaten to ensure the drive continued.

  And there is no creature more committed to the cause than the Australian mouselike marsupial known as antechinus. Its males have so much sex, with so many partners, so consistently, that every single one eventually drops dead. But they’re not perishing from something quick like a heart attack. No, no, that’d be too easy. This is total burnout, a burnout humans are incapable of suffering. As the males scamper about fornicating, they start to bleed internally. Their immune systems fail and their hair falls out. They even go blind toward the end, not that that’s going to stop them. In a world that’s faded to black, still they soldier on searching for females like sexual zombies, until at last they perish.

  The issue is a whole lot of testosterone. Levels of the hormone skyrocket in antechinus males during the breeding season, which is great if you’re looking to boost your sex drive, but not so great at promoting, oh, you know, emotional stability and general well-being. While on the upside, all that testosterone monkeys with antechinus’s sugars so it doesn’t need to feed for three weeks, allowing it to concentrate on sex sessions that last an admirable fourteen hours, it also leads to an unchecked release of cortisol, a stress hormone that supercharges energy levels but carries with it side effects like internal bleeding and hair loss and blindness.

  So where are the females in all of this? Are they simply suffering these chumps, letting them run roughshod over the forest, humping willy-nilly? Well . . . yes, indeed, but they have far more control than it seems. In fact, over the course of the species’ evolution, the females may have been responsible for creating the pandemonium in the first place.

  YOU SAY POSSUM, I SAY O-POSSUM, BECAUSE I’M AN AMERICAN, DAMN IT

  Australia is known as the continent of marsupials like antechinus, but you’ll find plenty of marsupials in the Americas. (The sole species in the United States is the opossum, with an “o.” Technically speaking, the possums without the “o” are a group in Australasia.) In fact, marsupials likely originated in the Americas, and at some point before 60 million years ago they made their way through Antarctica to Australia when the continents were still attached. Not that I’m trying to give the Americas credit for marsupials or anything. I’m just making a point.

  Antechinus is insectivorous, and for an insectivore in Australia, nothing is more exhilarating than spring, when the populations of all manner of bugs explode. And it’s in spring when the marsupial wants to raise her young because there’s plenty of food crawling about, initially not so much for her kids to feast on, but for the mom herself. Marsupials like antechinus are born highly underdeveloped compared to other mammals, like horses, whose newborns hit the ground running (well, maybe more like stumbling, but still), and therefore must spend a whole lot of time drinking milk and growing. Mama antechinus puts a ton of energy into milk production for her young—which, by the way, sit not so much in a pouch like koalas or kangaroos as in a kind of bowl on her belly—and insects are her fuel. It seems that antechinus females have shortened their breeding season over evolutionary time to synchronize the weaning of their young off of the milk and onto solid foods with the very peak of insect abundance, helping guarantee their survival.

  This in turn . . . guarantees the death of all those males the females mated with. Not directly, per se, but over the millennia males have had to adapt to solve the problem of a shorter breeding season by producing as much sperm as possible so they can shack up with as many females as possible as quickly as possi
ble. Indeed, antechinus testes are enormous relative to their body size. By coupling with so many females, the males are making up for the abbreviated breeding season afforded to them by evolution.

  It might all sound counterintuitive to the survival of a species, having males and females locked in a kind of evolutionary antagonism. But really it’s the opposite. An antechinus female is just asking more of the males. Yes, she’s mating with a bunch of fellas over those three weeks, so she can’t be choosy about her partners, unlike, say, a peahen, which can select the peacock with the most magnificent plumage. But because the healthiest males produce the most sperm, they have a better shot at fertilizing her. In her own way she’s “selecting” for the best genes of the bunch. Plus, her brood may be made up of young fathered by multiple males, and when she gives birth to as many as three times more babies than she has teats, only the strongest will win the struggle for nipples. The rest will perish and take their fathers’ inferior genes with them.

  ADVENTURES IN HAVING A SIX-INCH-LONG CLITORIS

  Hyenas employ a more active approach to selecting the sperm of certain males after copulation. Females have six-inch-long clitorises that look like penises. When they mate, the male inserts his penis into her “penis,” an act that biologists have noted takes some practice on the male’s part. The female’s enormous clitoris may have evolved to allow her to urinate to flush the sperm out if she decides she isn’t all that into the male after all. Perhaps unsurprisingly, throughout history all of this has earned the hyena a reputation as a sexual deviant. None other than Ernest Hemingway once described a hyena named Fisi as a “hermaphroditic, self-eating devourer of the dead, trailer of calving cows, ham-stringer, potential biter-off of your face at night while you slept.”