The Sting of the Wild Read online

  THE STING OF THE WILD

  THE STING OF THE WILD

  JUSTIN O. SCHMIDT

  © 2016 Johns Hopkins University Press

  All rights reserved. Published 2016

  Printed in the United States of America on acid-free paper

  2 4 6 8 9 7 5 3 1

  Johns Hopkins University Press

  2715 North Charles Street

  Baltimore, Maryland 21218-4363

  www.press.jhu.edu

  Library of Congress Cataloging-in-Publication Data

  Schmidt, Justin O., 1947– author.

  The sting of the wild / Justin O. Schmidt.

  pages cm

  Includes bibliographical references and index.

  ISBN 978-1-4214-1928-2 (hardcover : alk. paper)

  ISBN 978-1-4214-1929-9 (electronic)

  ISBN 1-4214-1928-9 (hardcover : alk. paper)

  ISBN 1-4214-1929-7 (electronic)

  1. Poisonous arthropoda. 2. Insect pests. I. Title.

  QL434.4′5.S36 2016

  595.7′165—dc23 2015026989

  A catalog record for this book is available from the British Library.

  Special discounts are available for bulk purchases of this book. For more information, please contact Special Sales at 410-516-6936 or [email protected].

  Johns Hopkins University Press uses environmentally friendly book materials, including recycled text paper that is composed of at least 30 percent post-consumer waste, whenever possible.

  To Debbie and Li

  CONTENTS

  Preface

  1 Stung

  2 The Stinger

  3 The First Stinging Insects

  4 The Pain Truth

  5 Sting Science

  6 Sweat Bees and Fire Ants

  7 Yellowjackets and Wasps

  8 Harvester Ants

  9 Tarantula Hawks and Solitary Wasps

  10 Bullet Ants

  11 Honey Bees and Humans: An Evolutionary Symbiosis

  Appendix. Pain Scale for Stinging Insects

  References

  Index

  PREFACE

  LET’S SADDLE UP and embark on an adventure. This adventure will be in our minds, not in the thorns, mosquitoes, and sweat of the real world. Cheating? Perhaps. But don’t all adventures take place in our minds as well as in our bodies? The adventure starts a million and half years ago in the savannas and open woodlands of Africa. Our band of 25 is relaxing at the base of a kopje, a large rock hill protruding from the open land. A few experienced men sit atop the kopje, scanning the landscape for potential threats and opportunities. Maybe there are some nearby lions to avoid, or a leopard lurking in a tree next to our path to the water hole, or maybe half a dozen raiders of a neighboring band are heading our way. Today is a good day with none of those threats; instead, we spy a just-born baby giraffe that appears unable to walk. Alert all boys over the age of 5 to accompany and learn from the experienced men how to seize this opportunity to feed the group a valuable treat of fresh meat. Three of the strongest men sprint-lope toward the distant giraffe to secure it from hyenas or lions that might also take note. Fortunately, no lions or hyenas had arrived on the scene, only circling jackals awaiting scraps after a kill.

  Two older men and an older boy rally the eager younger boys to follow and assist the experienced men ahead of them. As we hurry along through the grass, we remember that lions, leopards, and hyenas are not the only threats. Hey, what is that sinuous movement just to the left? Snake! Caution. Years ago an adventurous youngster was bitten by a snake, and he died. Snakes are dangerous. Maybe some snakes are not dangerous. But enough snakes are dangerous that all must be feared and avoided—better safe than sorry. That problem avoided, the trip continues. We pass under a baobab tree. Ouch, what stung me? Run, a beehive is located in the tree, and the bees are unhappy. Bees, too, can be a threat. We note the location and alert the advance men, who have driven off the mother giraffe with rocks and threatening sticks and are now butchering the young giraffe to bring back to the group. After returning to camp, the boys lead the excited men with their smoking torches to the beehive location and then stand back to watch. Two main honey hunters climb the baobab with their torches to chase away and rob the bees of their precious honey and combs of brood. The rest of us have learned that bees, like snakes, are inherently frightening and dangerous, and caution is required if we are to survive and be healthy.

  Our adventure is imaginary, but its message is real. Animals that can kill or hurt us are to be feared and treated with caution or avoided outright. For millions of years, our ancestors, whether human or protohuman, encountered dangerous animals, some large and powerful, some smaller but deadly, and some tiny but also able to inflict harm. These dangerous encounters indelibly etched innate fear of potentially harmful animals in our genes. We carry those genes with us to this day.

  In this book, I hope to share a love of the natural world and the beauty of all forms of life. Each animal has its own inherently interesting story to tell. Each story is awaiting our attention to be told. I was fortunate to be able to explore many adventures with some of the most beautiful and fascinating insects on earth—stinging insects. Stinging insects provide a wondrous insight into a variety of lifestyles and solutions to their own day-to-day survival challenges.

  The book is organized in two general sections. The first section comprising chapters 1 to 5 provides the background and theory that enhance the following chapters. The second, and larger, part is a series of chapters that go in-depth into one particular small group of insects. The reader is encouraged to skip around and read chapters in any order, as each chapter is intended to stand mainly on its own. Start at the beginning, or pick a favorite and jump in.

  I have a confession to make. The writing is littered with numerical superscripts. These are references to the sources of information and can be and—I might argue—should be ignored unless something piques particular interest. I beg that these numbers not be too much of a nuisance. Let’s go. I hope you enjoy the ride as much as I did.

  THIS WRITING WOULD NOT have been possible without the help of numerous people. Throughout my career, I have enjoyed many engaging and fruitful discussions about biology and stinging insects with numerous colleagues and friends, especially Steve Buchmann, Bob Jacobson, Bill Overal, Roy Snelling, Hayward Spangler, Chris Starr, and Murray Blum. Their ideas and discussions have enriched this book. I am indebted to John Alcock, Craig Brabant, Mathias Buck, Jim Cane, Joe Coelho, Eric Eaton, Kevin O’Neill, and Rolf Ziegler for providing information and fact checking for sections of the writing. In addition to providing ideas and information, Denis Brothers, Deby Cassill, Bill McGrew, Jon Harrison, Chuck Holliday, Jenny Jandt, Bob Jacobson, and Richard Wrangham critically read and helped improve various chapters. Louise Shaler, Elizabeth Taylor, and Tom Wiewandt encouraged me and aided in numerous ways to improve clarity, understanding, and presentation of the writing. Particular thanks to Margarethe Brummermann, Jillian Cowles, and Graham Wise for sharing and permissions to use their photographs.

  I would be remiss not to mention my editors, especially Vincent J. Burke and the tremendously talented team at Johns Hopkins University Press. I am immensely grateful to Vincent for his unwavering encouragement, support, and toleration of me throughout the writing. Without him, neither this book nor my joy (most of the time) in writing it would have been possible. Finally, I am indebted to my personal editor, adviser, and colleague Bob Jacobson who greatly helped in all aspects of the writing from sentence structure and spelling to presentation of the manuscript.

  THE STING OF THE WILD

  1

  STUNG

  Children are born naturalists.

  CHILDREN AR
E BORN NATURALISTS whose play is exploration of the environment surrounding them. Throughout most of human history, that surrounding environment was nature itself, a nature filled with sights, sounds, and smells of plants, animals, and the landscape. To the child, the ant walking in the play area or nipping at a food scrap was an object of interest. Equally interesting was the nearby flower with its intriguing bee, busy collecting nectar and pollen, and the lurking crab spider on the flower’s edge. To the growing brain, these experiences were exciting and valuable. At this youngest stage of life, fear is muted. Fear is mostly learned by play experiences and from nearby parents and adults. For their part, the adults in the community realize that play and learning are crucial for the developing young mind and encourage or allow mostly unrestricted play for the first five years. Play transforms the young human into an aware, observant, analytical, and adaptable individual prepared to face the world as an experienced, functional adult. But ever watchful adults are vigilant in making the environment secure for children to explore and learn in safety.

  Should a snake appear on the scene, quick action is taken to protect the children and to reinforce a preexisting fear of snakes. Over thousands of generations, as studies by Lynn Isbell and others have shown, humans developed a strong genetic fear and aversion to snakes and an instinct to avoid them. This instinct is biologically rooted.1 Those individuals who lacked a fear of snakes, or who failed at avoiding snakes, frequently were bitten, with dire consequences, and sometimes died. Genes governing detection and fear of snakes were positively adaptive for individuals possessing the genes. Those with genes that did not confer strong detection and avoidance abilities were slowly eliminated from the gene pool.

  As natural scientists, children learn to appreciate and value many elements in nature and to avoid others. By observing, formulating hypotheses, testing these hypotheses, noting the results of the tests, and repeating the process, they are engaging in science. This process comes naturally to children. No teachers are needed to instruct them in the method. Sadly, teachers later are needed to reinstill the scientific method after children grow older and have had this natural talent driven out of them. A paradox? Yes and no. Modern parents inherently sense that children love and need nature. That is why baby clothes are frequently adorned with fuzzy motifs of bumble bees or honey bees, and children’s beds abound with stuffed animals, such as bears, tigers, and even sharks. Parents know these animals can all be dangerous in real life, so why encourage them as intimate parts of their children’s lives? Could it be that parents know these mascots of nature encourage children’s excitement, learning, and comfort?

  My own early childhood in Appalachian Pennsylvania was not much different from that of many children around the world. My parents, unbeknownst to me, allowed and encouraged my exploration under their watchful eye. Frogs would be placed in pockets, mud pies made, and lightning bugs put in jars. I suspect these activities were not enjoyed by my mother, though they were tolerated, perhaps with the hope that I would outgrow them. At about five years of age, my well-being was sometimes entrusted to the care of my seven-year-old brother, my ten-year-old sister, and groups of older kids. I, as the youngest, needed to prove my worth to the group. One pleasant spring day the gang happened to notice a large mound of thatching ants from the genus Formica. These ants have no sting but produce copious quantities of formic acid, the most corrosive and acidic of the aliphatic organic acids, which they spray from the tips of their abdomens. They also bite. The combination of a solid bite breaking the skin and formic acid sprayed into the wound yields a sting-like pain. Some of the older boys dared me to sit on the ant mound, a challenge and an opportunity to prove myself that could not be missed. The ants swarmed over and under my britches and started biting my posterior. Up from the mound, down with the pants, and frantic brushing to get rid of them. No long-term damage was done, but I had learned an important lesson: insects can fight back. I continued with the group on to other adventures, a bit wiser and more experienced. Thus, my beginnings as an entomologist.

  AS CHILDREN GROW, their play turns to honing skills that may be needed in later life. For our ancestors, some of these skills were hunting and solving mysteries of nature. To master hunting skills, physical strength and coordination need sharpening, and nature must be observed, explored, and tested, and its mysteries probed. Today, in economically developed societies, hunting skills are less important, but the urge is still strong, especially in boys. The time-honored rural Pennsylvania tradition of declaring the first day of deer hunting season a school holiday exemplifies the modern continuation of old instincts. Old fields, fencerows, small woodlands, and streams abounded in the area of my childhood—perfect places for refining skills. Other than the dusty ball field, not much entertainment was available. Our small neighborhood group of six to eight boys, ranging four years in age span, was always on the alert for new adventures, whether we were climbing a challenging tree or discovering a bumble bee or hornet nest. I, perpetually the youngest, became a skilled tree climber, and, as the lightest, soon became the best tree climber in the group. In terms of running speed and throwing ability, I was at the bottom. One June day, as we were walking along a fencerow, an older boy discovered a baldfaced hornet nest deep inside the branches of a long-neglected apple tree struggling to produce green apples. What an opportunity. What a challenge. If we threw rocks at the nest, would they attack? If they attacked, would we escape? If they stung, would it hurt? Mysteries. To solve these mysteries and to test predictions that we could escape unscathed, the oldest boy grabbed a rock and, with the rest of us watching warily behind him, hurled it toward the nest. Poor shot. Nothing happened. We all ran a short distance. A pecking order of bravery then emerged with each boy sequentially grabbing a rock, approaching closer, throwing it toward the hidden nest, and all of us running. The rocks all missed, resulting in only a few hornets flying out to investigate, and nobody got stung. Finally, it was my turn. I found the perfect rock, approached closer than anybody had dared, and gave my mightiest throw toward the nest. A direct hit. Half the nest fell to the ground. The gang, clustered about 15 feet behind me, had a head start, and I learned how the term “mad as hornets” originated. This time the hornets meant business, and I was the closest and the slowest runner. About all I remember beyond this point was that one hornet managed to sting the back of my neck several times. The exact number of stings eludes memory but was at least three or four. It felt like someone had repeatedly struck the back of my neck with a hot branding iron. This was my first experience with what would several decades later become a 2 on the insect-sting pain scale.

  About this time, I changed my approach to stinging insects from the recipient of the experiments to the designer. I was a small, skinny kid with tiny fingers and sharp eyes for close-up objects, traits that later became perfect adaptations for my training as an entomologist. I wasn’t proficient at baseball or football, and marbles, our favorite game, had been recently banned from school. I had little else to do during recess other than observe plants and tiny animals on the playground. One day I saw a honey bee on a dandelion. I had been told that they could sting, so I decided to see for myself. This time, rather than be the recipient of the test results, I decided to test the hypothesis on my teacher, who was watching over the playground. I picked up the bee and put it on my teacher’s forearm. I learned that honey bees can sting, and my teacher learned that honey bees can be picked up by hand. My innocent test was without malice, though it did become the topic of discussion between my parents and the teacher whenever they met, even decades later. Lessons learned from stings are remembered a long time.

  PROMINENT IN MOST INSECT GUIDEBOOKS, the “cow killer”—sometimes called the mule killer—is a frequent summer visitor to yards and parks throughout the southern United States and much of the Midwest. Nearly an inch long, covered with a soft, inviting red and black fur, the cow killer superficially resembles an oversized ant. The common name “velvet ants” for cow killers and other
members of this worldwide and immensely successful family of more than 8,000 species is derived from its ant-like appearance. In reality, velvet ants are wingless female wasps. Male velvet ants are winged and look much like other wasps, albeit fuzzier and furrier. Female velvet ants easily vie for entry into the Guinness World Records for the greatest number of defenses known for any insect. First is their stinger, the longest stinger relative to body length of any of the true stinging insects. This is the group called the Aculeata and includes the stinging wasps, ants, and bees but not the parasitic wasps. The parasitic wasps differ from true stinging insects in that their stingers serve primarily to lay eggs and only secondarily to inject venom. Enhancing the effectiveness of the cow killer’s stinger, which can be half the total insect length, is the insect’s ability to aim it widely, so that it can sting a person or predator grasping any part of its body, whether it’s the head, thorax, or abdomen. The pain is instantaneous and searing, much like sticking a red-hot glowing needle into your thumb. The thumb recoils, but not the pain, which continues unabated for 5–10 minutes before gradually easing. This is in addition to a rashy-nettly pain reminiscent of a nasty brush with stinging nettle plants alongside a path near a stream. A natural urge to rub the rashy sting area increases the pain and the itch, a combination just shy of torture.

  During my graduate studies at the University of Georgia in Athens, I was called to a golf course whose operators were in a panic over a large aggregation of cicada killer wasps that had taken a fancy to some of the sand bunkers. Male cicada killers were busily flying around looking for females and challenging anything moving in their territory, including golfers. Meanwhile, numbers of beautiful, colorful cow killers, Dasymutilla occidentalis, were entering cicada killer burrows and looking for the wasps’ young as food for the cow killers’ young. I captured several of the cow killers and took them to the lab where I was analyzing their defenses. A young undergraduate student who was helping care for them decided one Friday evening to give them some honey and water. I received an urgent call about 11:30 p.m. from the campus infirmary concerning what to do for my panicked student who was stung while handling a cow killer and was frightened that he would not survive the night. About all I could do was advise that the bark was far worse than the bite and that while the sting was among the most painful known, the venom was among the least toxic known. He had no chance of dying, and after a little antihistamine and some tender loving care, the student was back in the lab the next day.