Getting the Bugs out of Tom Sawyer

An Entomologist's View of a Classic

John D. Evans

I could tell that the gentleman sitting next to me was trying to see what I was reading. His head was pulled back and tilted slightly to the side to get a better view into the valley formed by the book in my lap. He was trying to be subtle but he failed miserably. I glanced over and acknowledged him with a polite smile. He nodded and smiled back, a little embarrassed at being caught. In that quick glance, I got the impression of a giant, benevolent bird--a stork perhaps. His arms and legs were long and thin, and the head above the equally thin neck was crowned with a crest of white unkempt hair. A pair of gold rimmed glasses perched at the end of a beak-like nose and his eyes twinkled intelligently behind them. The quick movement of his head as he nodded was decidedly bird-like--a robin listening for a worm.

As I resumed my reading, he resumed his attempt to peek into my book. I had been in enough airport waiting areas stuck in delays to know how to pass the time. A good book was always my first choice; casual conversation with a complete stranger, my second. The latter was risky, for there was always the possibility of becoming hopelessly entangled in a conversation about Aunt Alma's gall bladder operation or Cousin Twilly's rotten second marriage. On the other hand, I have met some interesting people with some equally interesting stories. This gentleman had a unique quality about him that made me decide to take a chance--I tilted the book open in his direction. His head snapped up, but the startled look melted into a smile as he saw that I was not offended by his curiosity. He then unashamedly leaned forward, his neck extending, as he cocked his head and stuck his beak into my book.

"Ahh, Tom Sawyer," he said, nodding his approval. "One of my favorites." His voice was soft and melodious, his enunciation precise. "You're reading it for the first time perhaps?"

I closed the book on my index finger. "For the hundredth," I exaggerated.

He looked at me silently--patiently. I don't know what reaction I was expecting--shock, surprise, awe, but I didn't get them. He simply waited for the explanation that was due after such a comment. Perhaps there were books he had read countless times.

"I'm a teacher," I explained, and he nodded his head in understanding. "I read it year after year with my classes." I rolled the book over in my hand to expose the title. "I try to find some new approach, a new focus every once in a while. It keeps me fresh. I've studied it from just about every angle. This year I'm leaning toward a biographical approach--many of those adventures were Twain's. Right now I'm just trying to get the bugs out."

He threw his head back and let out a short, explosive laugh of delight that startled me.

"Wonderful!" he chirped. "What a marvelous way to phrase it: 'Getting the bugs out.'" He stroked his chin as he turned that phrase over in his mind, perhaps storing it away for future use.

"Are you a teacher also?" I asked.

"No," he smiled, "I'm an entomologist--insects are my game."

We fell silent for an awkward moment, neither of us sure what to say next.

"I wouldn't think The Adventures of Tom Sawyer would be your kind of reading." I said picking up the thread of our mutual interest.

"Quite the contrary! Tom Sawyer is teeming with insect life of the most extraordinary variety!" He seemed shocked that one who has read Tom Sawyer so often could be blind to such an obvious fact.

In a race to preserve my professional integrity, my mind buzzed through the plot in search of this teeming horde of insects, but I came up woefully short.

"You must be referring to the tick Tom played with in school--the tick he traded his tooth for with Huckleberry Finn."

"Well, yes," he said softly and there was something in his tone that told me that I had blundered. "There was that tick, yes. Technically it isn't an insect--it's in the class arachnida. It's a spider of sorts. Interesting nevertheless. Huckleberry Finn must have captured a common wood tick, Dermacentor variabilis. They like to crawl out on the tips of leaves and then . . ." he extended his arms like a giant crab, spread the fingers of his hands out like talons, and gently rocked back and forth, "they wait for a host to brush by. They grab the host," (his fingers snapped into tight fists) "and they feed on the blood of the victim. Once a mated female has gorged herself, she drops from the host, lays her eggs, and crawls out on another leaf. If the victim is a human, there is always the danger of Rocky Mountain spotted fever and tularemia, or rabbit fever. Nasty diseases. Nasty."

He shook his head sadly for a moment and then his face lit. "But if you want a disease carrier, you have to go to that fly Tom caught in church just as the minister ended his prayer. It was probably a common house fly, Musca domestica. I guarantee that Tom didn't know what he had in his hand besides that fly. It's been calculated that a single house fly carries with it as many as 33 million microorganisms in its gut, and perhaps a half a billion more on its feet, legs, body. It's a wonder the damned thing can fly!" He chuckled softly to himself. I smiled weakly.

"But they do," he continued, "and at a top speed of about five miles per hour. That's quite a feat with all that cargo. They can't land anywhere without leaving some of those bacteria behind. Tuberculosis, typhoid, cholera, diarrhea and many other diseases can travel around with that fly, and they do travel--up to twenty miles from the place where they were born. And everywhere they land, they drop off some of those nasty little bacteria." He leaned in confidentially. "You see, the problem is that they can't chew."

I raised my eyebrows, and he smiled, "They can only suck up liquids. When they find some solid food, they must first dissolve it. They spit out some saliva which turns the solid into a liquid, and then they suck it up--most of it anyway. It's what they leave behind that contains the bacteria.

"Their feet present another problem. Their feet are equipped with sticky pads that give them the ability to walk on walls and ceilings. It also gives them the ability to pick up germs: leprosy, gonorrhea, scarlet fever, polio, gangrene--the list goes on. And flies have no social conscience. They'll land on a rotting carcass or piece of filth and then go directly to your sugar bowl. And in spite of all the filth they contact, they are rather meticulous about their personal grooming, always rubbing their legs together, smoothing out their wings, dusting off their heads. And, of course, that helps deposit more germs wherever they land."

He paused reflectively. "I was always sorry Aunt Polly made Tom let that fly go. That one fly could lay 100 to 150 eggs at a time. The maggots that hatch mature in about two weeks, and then the females can begin to reproduce. One scientist calculated that a single pair of flies have the potential to produce five and a half quintillion offspring in a single summer! That's a 55 with seventeen zeros after it. Of course, that's supposing that every single fly survives to reproduce."

He looked over his eyeglasses and leaned in close. "Imagine how many offspring that fly of Tom Sawyer's was responsible for over the last 150 years!

"Of course, not all the insects in Tom Sawyer are harmful to man. The cricket is relatively harmless."

"Cricket?" I asked. "There's a cricket in Tom Sawyer?"

"Oh, absolutely. A field cricket, most likely--Gryllus." He reached over and gently removed the book from my hand. "May I?"

I nodded and he leafed through the pages.

"There is a house cricket, Acheta domesticus, which was introduced from Europe. That's the one Dickens labeled the 'Cricket on the Hearth.' One would assume that a cricket found in the house would be a house cricket, but that's not necessarily the case. Most of the time, the crickets you find in your house are field crickets that sneak in in the autumn. Besides, I doubt if Acheta domesticus would have ranged into Mississippi by the 1840s, but you never know. My best guess is that it was a common field cricket--a male. Here it is," he said pointing to a passage in my book. "Chapter nine: 'And now the tiresome chirping of a cricket, that no human ingenuity could locate, began.' Actually, it doesn't take much ingenuity to locate a cricket, but it does take patience. You see, the difficulty in locating a cricket is that it is one of nature's great ventriloquists. The chirping is made using the same principle as the violin. The male has a rough surface on the edge of his wing on the underside. On the upper side is a scraper." He placed his hands together and, pivoting them at the wrist, he rubbed his palms together. "When the wings slide over each other it is like a bow drawing across a violin string. It produces that familiar chirp. Usually the field cricket holds his wings up at a 45 degree angle for maximum projection." He held his hand out flat and tilted it up and down like the flap of an airplane wing. "But it will also lower it to produce a more muffled, distant sound. To us humans, the cricket's songs sound pretty much alike, but the field cricket has two classes of song. One is a common song, a series of triple chirps, and the other is the all important courtship song, a continuous trill. When he wants to attract a female, he increases the vibration frequency from 4,900 cycles a second to 17,000 cycles a second. Only the males make the chirping (we call it stridulations). The female hears it through tiny holes in her forelegs--no ears. It would be like you listening to music through your wrists. Hard to imagine, isn't it?"

I nodded.

"The field cricket has a cousin, the snowy tree cricket whose chirp can be used to tell the temperature. Count the number of chirps it makes in 15 seconds, add 40, and you'll have the temperature with amazing accuracy."

"Fahrenheit or Celsius?" I asked.

"Oh, my! Fahrenheit, of course!" He seemed shocked. "Crickets only chirp when the temperature is above 55 degrees and below 100 degrees--Faherheit, that is. On the Celsius scale they would positively roast!".

He paused. My ignorance seemed to put him off for a moment and he returned to the book. He pointed to the same page as before and his face took on a serious cast. "There was another insect at work in Tom's bedroom that night." He lowered his head and craned his neck into the book as he read, 'Next the ghastly ticking of a death-watch in the wall at the bed's head made Tom shudder. It meant that somebody's days were numbered.'

He looked at me gravely. "It's easy to understand how that superstition arose. What Tom was hearing was a death-watch beetle in the family Anobiidae. They like seasoned wood--furniture or timber. The one in Tom's room may have been boring into the headboard itself. It emits a ticking sound in its burrow by bobbing its head up and down--tapping the wood in search of a mate. In an active house, this ticking goes unnoticed, drowned out by other noises."

He leaned closer, his eyes widened, and he whispered, "Imagine, now, sitting by the bedside of a gravely ill person. Quiet pervades the room as the relatives wait for death to come. And then," his eyes moved from side to side and he pulled his head into his shoulders, "Tick! . . . tick! . . . tick! A mysterious noise from the dark shadows of the room seems to be counting off the last minutes of the dying. Supernatural forces must be at work!"

His features relaxed, and he continued in a normal conversational tone, "Of course after the person has died, the death-watch beetle continues to bore. Later on when his clicks are noticed deep in the middle of some sleepless night, the active imagination would naturally assume that someone else's last minutes are being counted--'Somebody's days are numbered' as Twain put it."

His brow wrinkled as if a troublesome thought came to him. "It's a wonder Tom heard the death-watch beetle with that cricket chirping away. Of course, if it was a cool night, its stridulations would be minimal. I suppose he could have heard it."

That must have satisfied him, because his face lit once again, and he continued happily: "They make wonderful pets, crickets. Give them a little place to live, some water, and feed them anything. They are omnivorous. They have the same diet you do. They eat all the same food groups plus some things that you may not want to eat like rubber, leather, and other insects. In fact, they'll even eat other crickets. They eat all the time; they are constantly hungry. Constantly! You don't have to walk them, and they make wonderful music. The Chinese and the Japanese have made an art form of carving cricket cages just so they can enjoy their songs." He shifted in his seat and threw one long leg over the other. "I've seen cages with covers of carved ivory and jade, and the Chicago Museum of Natural History has one on display carved from a walnut shell!

"Of course, their songs are not the only reason crickets are kept. For centuries the Chinese used them for sport--fighting crickets. They even had weight classes and personal trainers to make sure they were in proper trim before a fight. And just like the professional athletes, their diets were strictly watched. They were fed boiled chestnuts, mosquitoes, and, of course, rice.

"Yes, the cricket is a marvelous insect. It would have made a much better pet than Tom's Lucanus elephus.

"Lucanus elephus?"

"The Pinchbug. The one he kept in the percussion cap box."

"Oh, yes. The one the dog sat on in church."

"You must excuse my use of scientific nomenclature. Habit, you know. Lucanus elephus is the giant stag beetle, so named for its enormous mandibles. '. . . a large black beetle with formidable jaws,' I think were Twain's words." He stuck his thumbs into his dimples and with extended fingers imitated the insect's snapping jaws by drawing his fingertips together. "The mandibles branch as the beetle matures, like the antlers of a stag--ergo stag beetle. Generally they can be found in the woods on the ground--or on sandy beaches. With all that heavy artillery up front, you'd think they hunted for live prey, but they don't. They live on sap." He removed his glasses and polished the lenses with a white handkerchief. A look of doubt passed over his face. "Now that I think about it, it could have been a reddish-brown stag beetle that Tom caught, Psuedolucanus capreolus. Both have formidable jaws. I prefer to believe that it was the giant stag beetle though. They have a devil of a time righting themselves if they land on their backs, and the one in Tom Sawyer did just that and 'lay there working its legs helplessly in the air.' That sounds like a giant stag beetle to me. Tom must have captured a female. They have smaller mandibles than the male. Oddly enough, those large mandibles on the male are fairly weak. He can't get enough leverage for an effective pinch way out there on the tips. It's the female with the short, stubbier mandibles that can draw blood. Since that dog that sat on the Pinchbug yipped and carried on so, it must have been a female. For the most part, those 'formidable jaws' are all show. Oh, they can deliver a very firm pinch and they come in handy for self defense, but hardly enough to do any real damage to a human. Mostly they scare the bejabbers out of their enemies. I know I was a little hesitant to pick up my first Lucanus elephus, I can tell you."

He took a deep breath and smiled as if he were remembering that fond day of his youth, savoring it. With a little jerk, he was back to the present with a new topic.

"But for interesting beetles, I don't think there are any that can compare to the tumblebug."

"The tumblebug! On Jackson's Island!" I was proud to be able to salvage a bit of my professional integrity by recognizing the source of his reference.

"Yes, probably Pinotus carolinus. What a marvelous little insect the scarab is! Sacred to the Egyptians as a symbol of the movements of the planets and rebirth. When the Egyptians saw this little creature pushing around its maternal ball of dung, they must have realized what a special little beast it was. Not many insects go to such trouble to prepare for their young, and the scarab is perhaps the only instance in the insect world where the male assumes some of the responsibility of parenting. Once a source of dung is located, the adult will use his clypeus--that's the shield of his broad head, to scrape and collect only the choicest morsels for its ball. When the adult beetles eat, they are not half so particular about quality, but for its young, only the best will do. The beetle then uses his back legs to shape a perfect ball. The legs are long and thin like a pair of calipers, and that is exactly how the tumblebug uses them--to shape the ball into a sphere whose diameter must be large enough to insure the right volume of nutritious matter to sustain the life of the larva. Once the ball is of suitable size, the beetle begins to push backwards with his hind feet against the ball and his head toward the ground as he maneuvers it to a safe place." He leaned out of his chair with surprising agility and began a backward walking gesture with his hands. "No obstacle will daunt him. He will push and push until his goal is reached." He sat back in his chair. "Should the ball roll back down a hill, he will try again and again until he succeeds. Talk about perseverance! Once the ball is out of harm's way, a vertical hole is dug to hide the ball, and a single egg is planted with it. Then, when the larva emerges from the egg, it finds itself surrounded by food that is highly nutritious. When it matures and leaves its tunnel, the remaining dung fertilizes the earth. It is a very beneficial insect, and a nice role model for parents where both the husbands and the wives take a hand in the welfare of the children."

After a brief pause, he shook his head disapprovingly. "That is more than can be said for Myrmeleon immaculatus, the antlion. The larva of the antlion must fend for itself. . . ."

I held up my finger to interrupt, and he paused.

"I don't remember an antlion in Tom Sawyer. I remember the fly, the tick, the tumblebug and the pinchbug, but an antlion?"

"The Doodlebug, remember?" He flipped frantically through the pages of my book. "Here it is: Tom 'searched around until he found a small sandy spot with a little funnel-shaped depression in it. He laid himself down and put his mouth close to this depression and called: Doodlebug, Doodlebug, tell me what I want to know.' Well, the insect Tom was addressing was a larval antlion. And as I was saying, the larva must capture its own food, and it is done in a most ingenious way. It finds a nice piece of sandy or loose soil and begins to walk backward in a circle. As it goes, it dips its head into the ground and flings sand out of the circle. Eventually, a cone-shaped pit is formed two or three inches across. When it is satisfied that the pit is ready, the antlion wiggles into the sand with only his mandibles sticking out. With any luck, an ant will come along and slide into the pit. The more the ant scampers to get out, the deeper into the pit it slides, closer to the waiting jaws. Sometimes, if the ant appears to be succeeding in his escape, the antlion will fling sand at the ant, barrage after barrage, until it falls within its reach. And then--it's lunch time!"

"As I remember," I interrupted, "Tom was trying to see if something interfered with one of his superstitions. When Tom spoke to it, it retreated. That told Tom that witches were at work!"

"I don't know about witches, but I do know Doodlebugs. I imagine the vibrations of Tom's voice made the antlion think that there was an ant in its trap. When it stuck its head up, it realized that it was a false alarm and retreated. Indeed, it may have been frightened by seeing a large mouth so close to its home. It is the same with the Ladybug, Hyppodamia convergens. When Tom says, 'Ladybug, Ladybug fly away home, your house is on fire, your children's alone,' he really believed that it was going to see about the fire and her children. Of course, we know that the only reason it took off is because his breath disturbed it."

There was a refreshing silence as he stared reflectively down at my book. He shook his head sadly.

"It's a shame to play such a mean trick on such a lovely insect. The ladybug is a true friend of the farmer." His face brightened again as he launched into his next topic. "They eat aphids, scale insects, and greenflies that can ruin a farmer's crop. One ladybug, or ladybird as they are sometimes called, was monitored as it ate 90 adult scale insects and over 3,000 larvae during its own larval stage. Some farmers even buy large numbers of them to protect their crops." He winked at me mischievously and nodded knowingly. "I'll bet you are wondering where you go to buy ladybugs and who supplies them. Well, they are really easy to collect. Hyppodamia convergens have a remarkable homing instinct and in the West they gather in great masses where their parents gathered for the winter. Horticulturists harvest them by the millions and store them for later on when the aphids show up in the fields. In the East, they gather in smaller masses under the weatherboarding of your house. It's not worth harvesting them in the East."

It was at this point that my long delayed flight was announced. My friend handed me my copy of Tom Sawyer and as we gathered our belongings he continued his enthusiastic chatter.

"There are many other insects mentioned in that book: inchworms measuring for Tom's pirate uniform, butterflies. . . ." He was standing now, and his face took on a troubled look. "Twain was shamefully vague in his description of them, and with over 12,000 species found in North America, there is no telling what species Tom was seeing."

He fell in beside me as I walked toward the boarding gate. "And then there was that procession of ants on Jackson's Island. According to Twain, one of those ants was struggling with a spider 'five times as big as itself' and 'lugged it straight up a tree trunk.' It was probably a procession of black carpenter ants, Camponotus pennsylvanicus. You see, most ants nest underground, but the carpenter ant will nest in the dead wood of a tree trunk.

"Twain really missed the boat there. If he had only concentrated more upon those ants and how they got that dead spider, he would have really had something!"

The attendant took out tickets and we marched down the covered ramp to the plane. I offered a silent prayer that our seats were far removed from each other.

"Now that inchworm that crawled on Tom's leg--it really wasn't a worm. It was the larva of a geometer moth, one of 1,200 species found all over North America. The reason they rear up and go 'sniffing around,' as Twain put it, is because. . . ."