Nature’s Tricks and Treats

Giant water bug ~ Lethocerus americanus

Motionless, seemingly at rest above the shallow waters of a roadside ditch, the creature caught my eye — dark enough to be noticed; large enough to invite a closer look.

In time, I learned I’d found a giant water bug: the largest true bug in the United States. Nearly four inches in length with a flat, oval-shaped body, a short, pointed beak on the underside of its head, and overlapping wings at the end of its abdomen, the creature seemed entirely capable of living up to its nickname: the toe-biter.

Adapted to living in water, the giant water bug breathes through snorkel-like tubes located at the end of its abdomen. When extended to the surface of the water, the tubes collect air from the atmosphere, then add it to a bubble of air trapped beneath the insect’s wings. From that bubble, air enters its body through holes in its abdomen: one of the neatest bits of engineering in the insect world.

Using its flattened hind legs as oars, the water bug skulls over to a plant growing near the surface of a pond or stream and secures itself. After snatching an unfortunate victim with the hook-shaped claws of its forelegs, it pierces the prey with its beak, injecting powerful toxins which paralyze and liquify the victim — bones and all — for easy consumption.

Able to catch and consume creatures fifty times its size, the giant water bug’s menu is extensive; it feasts on aquatic insects, crustaceans, tadpoles, salamanders, fish, and frogs.

Especially active in late summer and early fall, giant water bugs begin moving from shallow water to deep, where they can continue to hunt during the cooler months and bury themselves in mud during cold spells. This season of movement is the time that they’re most likely to be seen by humans.

One of the more memorable passages from poet and naturalist Annie Dillard’s Pilgrim at Tinker Creek involves her own encounter with a giant water bug, and the frog that became its victim. The tale seems entirely suitable for Halloween, and far more haunting than a grimacing jack-o-lantern or bed-sheeted ghost.

A couple of summers ago I was walking along the edge of the island to see what I could see in the water, and mainly to scare frogs… As I walked along the grassy edge of the island, I got better and better at seeing frogs both in and out of the water. I learned to recognize the difference in texture of the light reflected from mud bank, water, grass, or frog.
Frogs were flying all around me. At the end of the island I noticed a small green frog. He was exactly half in and half out of the water, looking like a schematic diagram of an amphibian, and he didn’t jump.
He didn’t jump; I crept closer. At last I knelt on the island’s winter-killed grass, lost, dumbstruck, staring at the frog in the creek just four feet away. He was a very small frog with wide, dull eyes. And just as I looked at him, he slowly crumpled and began to sag. The spirit vanished from his eyes as if snuffed. His skin emptied and drooped; his very skull seemed to collapse and settle like a kicked tent. He was shrinking before my eyes like a deflating football.
I watched the taut, glistening skin on his shoulders ruck, and rumple, and fall. Soon, part of his skin, formless as a pricked balloon, lay in floating folds like bright scum on top of the water: it was a monstrous and terrifying thing. I gaped bewildered, appalled. An oval shadow hung in the water behind the drained frog; then the shadow glided away. The frog skin bag started to sink.
I had read about the giant water bug, but never seen one. “Giant water bug” is really the name of the creature, which is an enormous, heavy-bodied brown bug. It eats insects, tadpoles, fish, and frogs. Its grasping forelegs are mighty and hooked inward. It seizes a victim with these legs, hugs it tight, and paralyzes it with enzymes injected during a vicious bite.
That one bite is the only bite it ever takes. Through the puncture shoot the poisons that dissolve the victim’s muscles and bones and organs — all but the skin — and through it the giant water bug sucks out the victim’s body, reduced to a juice. This event is quite common in warm fresh water. The frog I saw was being sucked by a giant water bug.
Of course, many carnivorous animals devour their prey alive. The usual method seems to be to subdue the victim by downing or grasping it so it can’t flee, then eating it whole or in a series of bloody bites. Frogs eat everything whole, stuffing prey into their mouths with their thumbs. People have seen frogs with their jaws so full of live dragonflies they couldn’t close them. Ants don’t even have to catch their prey: in the spring they swarm over newly hatched, featherless birds in the nest and eat them tiny bite by bite.
That it’s rough out there and chancy is no surprise. Every living thing is a survivor on a kind of extended emergency bivouac. But at the same time we are also created. In the Koran, Allah asks, “The heaven and the earth and all in between, thinkest thou I made them in jest?”
It’s a good question. What do we think of the created universe, spanning an unthinkable void with an unthinkable profusion of forms? Or what do we think of nothingness, those sickening reaches of time in either direction? If the giant water bug was not made in jest, was it then made in earnest?
If we describe a world to compass these things, a world that is a long, brute game, then we bump against another mystery: the inrush of power and light.Unless all ages and races of men have been deluded by the same mass hypnotist, there seems to be such a thing as beauty, a grace wholly gratuitous.
About five years ago I saw a mockingbird make a straight vertical descent from the roof gutter of a four-story building. It was an act as careless and spontaneous as the curl of a stem or the kindling of a star.
The mockingbird took a single step into the air and dropped. His wings were still folded against his sides as though he were singing from a limb and not falling, accelerating thirty-two feet per second per second, through empty air. Just a breath before he would have been dashed to the ground, he unfurled his wings with exact, deliberate care, revealed the broad bars of white, spread his elegant, white-banded tail, and floated onto the grass.
I had just rounded a corner when his insouciant step caught my eye; there was no one else in sight. The fact of his free fall was like the old philosophical conundrum about the tree that falls in the forest. The answer must be, I think, that beauty and grace are performed whether or not we will or sense them. The least we can do is try to be there.

 

Comments always are welcome.
For the complete passage from which Dillard’s tale was excerpted, please click here.

Rest Stop

Not far from the spot where I discovered salt marsh morning glories abloom, this dragonfly paused at the edge of a water-filled ditch while dozens more of its species continued to buzz over the water.

I’ve tentatively identified it as a black setwing (Dythemis nigrescens), a dragonfly native to Texas, New Mexico, Arizona, and parts of Mexico. Sometimes confused with the slaty skimmer (Libellula incesta), the black setwing is smaller, with a more slender abdomen.

According to Odonata Central, these setwings enjoy perching atop twigs near the water, generally in open areas. That fits the behavior of this dragonfly, except that it hadn’t chosen a twig for its perch. This expanded view shows its resting spot for what it is: the four-inch long seed pod of a slim milkweed plant (Asclepias linearis).

Though obscured in the photo above, the delicate flowers of this milkweed are eye-catching: perhaps to the eyes of a dragonfly, the pods are equally attractive, and even more useful.

Slim milkweed (Asclepias linearis) in bloom

 

Comments always are welcome.

Some Friends for the Big Green Guy

The Big Green Guy ~ photo by Steven Schwartzman

This little marvel munching away on a gaura leaf, clearly unwilling to interrupt his meal in order to tidy up for the camera, has been tentatively identified as the larva of a white-lined sphinx moth (Hyles lineata): the same moth I featured recently on The Task at Hand.

The first time I saw the creature, I dissolved into giggles and immediately dubbed him the Big Green Guy. His vulnerable chubbiness, his tiny, multi-purpose feet, his air of concentration, his apparent lack of embarassment at being revealed as a messy eater: all evoked a response of absurd protectiveness.

Unable to help myself, I emailed his image to friends. Despite mixed reviews, everyone recognized it as a caterpillar, although some less sensitive souls deemed it ‘just’ a caterpillar. “Yes,” I said. “It is a caterpillar. But it’s not just any caterpillar. It’s an Alice in Wonderland, ‘Let me look you in the eye and ask you some questions’ caterpillar.”

Eventually, I purchased and hung a print of the creature on my wall. A neighbor said, “You might as well have mounted a collection of cockroaches.” I considered her judgment unnecessarily harsh, and said so. “To each her own,” she said.

Over the months, I began to wonder why I never had found a caterpillar. I saw monarchs being raised here and there, and occasionally a friend would find a chrysalis hanging from a lawn chair or a shrub, but caterpillars of any sort evaded me.

Then, in late October of this year, I noticed yellow tape along a roadside, attached somewhat casually to stakes. Suspecting that someone might have marked a milkweed patch, I stopped to explore. When I did, I not only found milkweed plants, I found a group of monarch larvae happily feeding: as plump and adorable as the Big Green Guy.

This one appeared to be sampling a stem.

A second was making short work of what seemed to be an especially tasty plant. At the time, I didn’t notice what appears to be an empty chrysalis nearby.

Focused on eating as much milkweed as they could, as quickly as possible, the group clearly wasn’t interested in posing, but they provided a wonderful hour’s entertainment.

In a recent post on his Learn Fun Facts blog, Edmark M. Law offered this quotation from Charles Dickens’s 1850 novel, David Copperfield:

Indifference to all the actions and passions of mankind was not supposed to be such a distinguished quality at that time, I think.
Yet I have known it very fashionable indeed. I have seen it displayed with such success that I have encountered some fine ladies and gentlemen who might as well have been born caterpillars.

Dickens might have sought a different analogy, had he met the Big Green Guy and his friends.

Comments always are welcome.