Posts Tagged ‘entomology’
September 15th, 2011 | Meera
I have a small number of tracks that I follow through the halls of the Field Museum almost every time I go there. The museum, as those of you who have visited it will know, is a cavernous structure. Its walls contain more than a million square feet of floor space, less than half of which is devoted to publicly displayed exhibits—so if you have been there, imagine how big it seems to you when you’re standing in that enormous central atrium and then just go ahead and double that feeling.
I’m no mathematician, but I’m going to go out on a limb and say that even if all you ever wanted to do was travel back and forth between two spots in the entire building—say, the doors of the West entrance and the bird prep lab on the 3rd floor—you could probably devise a near-infinite number of different routes to take.
Some might whisk you through the plant hall, others past the ancient Americas; some would wind their way around the feet of dinosaurs, others plunge you deep inside the heart of minerals. If you had an all-access-granted ID pass, no staircase, door, or elevator would be closed to you; you could make the Field your only home, and walking it your only recreation, and still you’d likely need more than one lifetime to traverse each one of the possible passageways it contains.
Me, I’ve been there close to a hundred and fifty times in the past two and a half years. And almost every single time I enter its doors, I take one of perhaps three, or, at most, four paths to get where I am going. It’s embarrassing, actually. I feel like an ant following some set of strange, self-made, incredibly persuasive pheromone-laden tracks; each week I sniff out what I left there seven days before and lay down new markers in the same old places as I crawl.
All this, friends, to explain why I have certain very favorite objects at the Field. For the things in the museum that I adore the most just happen to be, besides inherently lovely and fascinating, also conveniently located right along my ant-tracks.
The one I thought I’d share with you today is a large pair of drawings, mounted together in a single frame on a wall on the ground level, near the McDonalds. Each depicts multiple whole and partial specimens of Rove beetles: a large group of beetles belonging to the family Staphylinidae that, as far as I can gather, get their name because they’re fond of getting places by scurrying inconspicuously across the ground instead of taking wing.
(Their other common characteristic is a pair of unusually short forewings that leaves their abdomens half exposed, like teenage girls wearing midriff-baring t-shirts. But unlike most teenage girls, they’re shy, sleek little things.)
I’ve admired these drawings dozens of times, but today was the first time I stopped to photograph them, and it was also the first time I noted the name of the person who created them. He was Alexander Bierig. He loved beetles. And, as we shall see, he had something to teach me.
Alexander Bierig was born in 1884 in Karlsruhe (the prettiest fan-shaped German city you’ve never heard of). He was the youngest of the four sons of the shoemaker Ludwig Georg Phillipp Bierig, who apparently spent his spare time writing plays and poems. Nice work, Ludwig.
What I love about Alexander’s life story is that it has a wonderful sort of pivot in the middle of it; the first half of his biography is entirely respectable and sedate and conventional, and then he meets someone who changes things for him forever, and suddenly he embarks on a life of adventure! And jungles! And insects! To wit:
Respectable: After studying to be a graphic artist in his home town, Bierig spent a few years living and working as an illustrator in Berlin, where he got married. Then he moved to Paris with his wife Katherine, taught a few private art classes, drew pictures for scientific articles and books, and had his only child, a son who would one day grow up to be an architect.
When World War I began, the Bierig family moved back to Karlsruhe, and Alexander was soon called up to serve in the German army. The end of the war also marked the beginning of the end of Bierig’s staid life, because it proved impossible for him to find work as an artist in a country whose economy had been so thoroughly devastated.
Pivot: What happens next seems to have been that in 1919, some Russian friends of the Bierigs decided to move to Havana in search of work. This was a sensible enough plan, since at the time Havana was just starting to undergo two huge booms: one in sugar and one in tourism. There was definitely more money flowing to it than to Karlsruhe. Inspired, Alexander decided to move his little family to Cuba too.
In Havana, Bierig walked down some old paths for a while. He freelanced as a graphic artist, became a teacher of drawing and natural sciences at the German School, and kept giving private art classes.
He also met the person who would be his pivot: an eminent Costa Rican entomologist named Ferdinand Nevermann. Bierig had become interested in beetles while he was in Paris, and had even written a scientific paper about two species of Carabidae after he moved back to Karlsruhe. But it was his friendship with Nevermann that ignited what would become a lifelong love affair with field work, collecting, and Rove beetles in particular.
(At some point in 1923, Katherine—who didn’t like Cuba or its climate at all—moved back to Germany with their son. I haven’t been able to determine whether she was also irritated with her husband’s growing obsession with beetles, but I wouldn’t rule it out. In any event, the marriage didn’t survive the separation. Alone in Havana, Bierig befriended several other zoologists, learned everything there was to learn about Rove beetles, and began publishing more scientific papers. But it wasn’t until 1938 that his second life really began.)
Adventure!: In 1938, Bierig went on his first field trip, an excursion with Nevermann to Costa Rica. I don’t know how the trip would have been graded by scientific criteria, but by all other benchmarks things did not go well. There was An Accident. I wish I could tell you with certainty exactly what this accident was, but the small amount of literature I’ve been able to find on the subject contains conflicting details.
One story is that Nevermann and Bierig were attacked by a jaguar which pounced on them from a treetop, and Nevermann was killed, while Bierig was severely wounded. Another is that Nevermann was out collecting insects at night, by headlamp, and was accidentally shot by a local hunter who mistook his light for the glowing eyes of a large animal. One version of this second story has Bierig there and wounded, too; another doesn’t mention Bierig at all.
What is clear is that Bierig’s first exposure to field work was extraordinarily traumatic. It resulted in the death of his scientific partner and good friend. It seems to have gravely injured him. Yet one year later—clearly intoxicated by the glorious, colorful, totally overwhelming world of tropical wildlife that he’d found in Costa Rica—he returned to the same country to continue his beetle collecting. And he never left.
In Costa Rica Bierig would become a professor of entomology in San José, author dozens of scientific papers, collect approximately 26,000 individual specimens, and describe over 150 new species and over 30 new genera of insects (most of which were Rove beetles and all of which, of course, he would also illustrate). He was a field biologist extraordinaire. He was also a celebrated and often exhibited artist in his adopted country, remembered till this day for his influence on an entire generation of Costa Rican painters and illustrators.
The final years of Bierig’s life were not easy ones, although they had some bright spots (like the happy discovery of a granddaughter he’d never known he had). He began to lose his eyesight, became rather solitary, and finally died in 1963 after a long and painful illness. With no one to maintain them, his drawings, papers, and the tens of thousands of type specimens he’d collected began to deteriorate in the tropical heat and humidity.
Fortunately for posterity, this is when they were scooped up by the Field. And very fortunately for me, a few of Alexander’s drawings happened to find themselves (nearly 50 years later) located on one of my three or four short and unimaginative ant-trails through the museum.
As far as I can tell, Alexander was pretty damned good at roving. In tribute to him, next time I go into the Field Museum, I’m going to experiment with some different routes to where I’m going. I bet I’ll find a new favorite object or two. And if today is anything to go by, I might also find another great story to tell you.
(This is a self-portrait Alexander drew. I think he looks fantastic.)
March 10th, 2011 | Meera
While preparing three fall birds, prosperous with pre-migratory feasting, something occurs to me that I’ve wondered about before, so I ask Mary about it.
“Mary, do the bugs* like fat?”
“Mmm, not really. If they’re eating well, they’ll go through anything; they’ll eat through cartilage, tendons, you know. But if they’re being fussy you’ll just come in and find big gobs of fat they’ve left behind.”
There is a pause while I consider the word “fussy” in relation to flesh-eating beetles.
“They’re spoiled,” I decide.
“Yeah. They are.”
Later, we have a conversation about whether it is theoretically possible for fat to be deposited between the two layers of fused bone that make up an adult bird’s skull. Mary says she’s seen what looks like exactly that in the course of cleaning out skeletons from the bug room, but she isn’t sure it’s a documented phenomenon.
It isn’t too long after both these chats that I take a break to enjoy the ham and cheese sandwich I’ve brought for lunch.
*Beetles aren’t true bugs, but everyone in Birds and Mammals calls the dermestids “the bugs,” and the room they live in is the bug room. I am not sure if the Entomology Division objects to this.
July 28th, 2010 | Meera
A small, straight twig, held steady between the spokes of a rotating bicycle wheel as it speeds up, slows down, speeds up, slows down, falls still, and then is set to spinning again.
The last gasps of an aerosol can, shaken and sprayed by a determined hand, liquid and air shunted out together through a tiny hole in ragged, pulsating bursts until nothing more remains to be ejected.
A wind-up car that you turn with a key, released at its tautest on a table and allowed to travel as far as it will go, the key in its back clicking down in lengthening ticks its brief, meandering adventure.
The world’s most precise drummer gently sweeping a metal brush back and forth, back and forth, back and forth across his snare, in a lull between the blare of the saxophone and the whalesong of the bass. His hand moves so fast you can hardly believe it, a blur to look at; but he slows. He stops. Gives over his gentle solo.
A bullet-shaped UFO, lights wavering, hovering in the dead silence of the night—approaching its landing spot, cutting its engine, and gliding to rest before my disbelieving eyes.
Superstrings, vibrating with the precise harmonics required to create the fundamental material constituents of our universe and all that it contains.
Sand slipping through an hourglass, each grain squeaking against the sides of that narrow channel before falling, with the clink of a coin, into the bottom chamber.
A stream of water dripped onto a hot stove. Sizzling. Silence. Water into air.
June 6th, 2010 | Meera
In the fall of 1889, just past the height of bug-season in his home state, Henry C. M’Cook—then-Vice-President of the Academy of Natural Sciences of Philadelphia and Vice-Director of the American Entomological Society—wrote a lively article for the North American Review in which he outlined ways of mitigating the reign of the pestilential mosquito. Four pages into his arguments, he found himself distracted (as we all are, from time to time) by a dragonfly.
I have read of a school—if memory serves me truly, it was situate in that highly-developed center of American civilization, New York City—whose session was broken up by the advent of an innocent dragon-fly through an open window. An alarm raised by one scholar passed through the entire room: “A devil’s darning needle! A devil’s darning needle!” The ominous phrase, piped in the shrill quaver of terrified childhood, alarmed the teacher, and the agitation became so general that the school had to be dismissed as an act of humanity.
I love the gentle sarcasm in that. “Act of humanity.” Dr. M’Cook, you were one sly scientist.
In their 2005 book A Dazzle of Dragonflies, Forrest Mitchell and James Lasswell explain that the dragonfly-epithet “devil’s darning needle” has its origins in the Europe of the Middle Ages. The long and slender shape of the insect’s body, combined with the superstitious belief that it, like the fly—consort of Beelzebub—was in league with the darkest of forces, produced a myth durable enough to make the journey with the colonists to the United States. Today in Iowa, the authors write, “devil’s darning needles sew together the fingers or toes of a person who falls asleep…in Kansas, they may sew up the mouths of scolding women, saucy children…and profane men.”
Dragonflies, of course, do no such thing. In fact, creatures belonging to the order Odonata—Latin for “toothed,” a reference to the chewing mandibles dragonflies share with most other insects—and the infraorder Anisoptera—Latin for “unequal wings,” because dragonflies have broader hindwings than forewings—have no sting, let alone needlepoint. They are perfectly harmless to humans, if not to their prey: smaller insects, including ants, bees, and the mosquitoes that so irritated M’Cook.
I tell you these things today because I spent the morning at Promontory Point, winding my way along the rocky strand where Lake Michigan hits Hyde Park—and, by the by, watching a levitation of dragonflies dart back and forth across the path and wheel between tall grasses. (I could find no consensus on the proper collective noun for dragonflies, if any exists. Mitchell and Lasswell offer dazzle; I went my own way.) Whatever you call them, they were magnificent: swift and glittering and alarmingly unpredictable—I had to duck, once, to get out of the way. So erratic were their flight paths that they seemed almost invulnerable to the greedy swoops of the ring-billed gulls that flew overhead.
I’m not sure which of the hundred or so species of dragonfly known to be seen in Illinois I was looking at. But there must have been at least two distinct kinds dancing in between each others’ wings, because all were fully grown, but some were large and some were small. Dragonflies, like almost all other winged insects, have already gone through their final molt by the time they are able to fly, and so every dragon in the air is an adult.
I saw a flash of blue, though I do not think what I saw was little enough to have been the impossibly wee Elfin Skimmer (Nannothemis bella). And it is a little late now for the Green Darner (Anax junius), a common sight around Chicago in the spring and fall. (The Darner is one of a tiny number of dragonflies that migrate seasonally. Recent study suggests that the most persevering of these creatures may cover round-trip distances as long as 16,000 kilometers. This is, coincidentally, nearly identical to the length of my own annual migration between Chicago and Singapore—a fact that floors me. When I get off that plane, I am bone-tired, dog-tired, dead-tired: but apparently not dragonfly-tired. I am shamed by insect-endurance.)
The other reason I tell you these things today is that the last time I got as close to an Anisopteran as I did this morning, I was in the New Orleans bayou, a year after Katrina. I remember being surprised then by their calm fearlessness: the way they would land on the edges of leaves right there under my nose, and turn their heads, set with eyes as heavy and faceted as precious stones. They let me come close enough to feel the air brush away from their wings as they took off again, and maybe their tranquility came from the sure and certain knowledge that they far outnumbered our curious band of swamp explorers. The coastal plains of Louisiana are dragonfly country. The air there is thick with the sound of their flight.
Which is why it is so hard to think of the way that country has changed over the past six weeks.
I. Oil Prevents Emergence
By the time we see a dragonfly, it has reached the end of its multifarious life cycle. Female dragonflies lay their eggs in or near water, and the nymph and larval stages both exist aquatically. The larvae of some species may spend a few months or as long as several years underwater before crawling above the surface to metamorphose into their final, satin-winged forms.
(I love thinking about this life, by the way—a life so focused on growth and preparation, in which the fulfillment of one’s basic plan for existence is vital, of course, but temporally inconsequential. I imagine myself like this right now, hunkered down, eating and growing and having no idea of what ultimate shape I will take, what satin wings I will have.)
But on the Gulf Coast, oil has flowed into the salt marshes where dragonflies lay their eggs—spread itself like a blanket over their underwater atmosphere. As long as its black covering remains, dragonfly larvae from eggs laid weeks or months or years ago will be unable to split the water’s surface without at once covering themselves in pitch.
II. Oil Looks Better Than Water
Like many other insects, fish, and mammals (though not humans), dragonflies are sensitive to the presence of polarized light. The light receptor cells in their retinas are full of the photoreceptive protein called rhodopsin. So are ours. But in the human eye, rhodopsin molecules within each cell are arranged haphazardly, with their axes running at random angles. As a result, our eyes collect light indiscriminately. We have no way of differentiating scattered light, whose waves vibrate in all directions, from polarized light—in which vibrations have been restricted to a single plane.
In dragonfly eyes, rhodopsin molecules within each light receptor cell are aligned in parallel. That means the molecules preferentially absorb beams of light whose waves are vibrating in the same direction and enter the eye in the same orientation: thus hitting all those neatly arranged rhodopsin molecules at just the angle towards which they collectively lean. In other words, dragonfly eyes are especially greedy for polarized light. And since large, flat bodies of water like ponds, lakes, and oceans polarize light as they reflect it, that’s a pretty helpful attribute for an insect that hunts, mates, and lay its eggs over water.
Except water isn’t the only thing that reflects polarized light. Not by a long shot. Dark-colored cars do it. Glossy black tombstones do it. Both have been shown to confuse insects like dragonflies, which often choose to mate above such objects instead of above water, and even attempt to lay their eggs on these strange, inhospitable surfaces.
And then there is crude oil. Thick, black, shiny crude oil, the kind covering vast swathes of the Gulf of Mexico at the moment. In the late 1990s, a group of Hungarian scientists found themselves intrigued by the odd behavior of dragonflies that hovered and mated around the shiny black surface of the open-air waste oil reservoir in Budapest. By comparing the number of dragonflies that were caught in traps containing plain water, salad oil, and crude oil, the researchers convincingly demonstrated that the glittering creatures “can be deceived by and attracted to crude and waste oil.” In fact, their results suggested dragonflies actually prefer crude oil to water, probably because oil more strongly polarizes light.
On the Gulf Coast, then, it seems more than likely that as we speak, dragonflies are taking oil for water.
We are oiling the devil’s darning needle—just when it would, perhaps, do very well to sew together our fingers and toes.
Photo: Gerald Herbert/AP