Showing posts with label metamorphosis. Show all posts
Showing posts with label metamorphosis. Show all posts

Tuesday, August 23, 2011

Have you seen...

I had just made the last trip outside for the night, flipping on the porch light and grabbing the few remaining items from the clothesline across the yard. Glad that I’d caught them before the heavy summer night could leave its cool dampness with them once more, clothes in hand, I moved mindlessly toward the back door, already falling into sleep.
The sounds from the woods and field, strong and rhythmic, buzzy, buggy--on any other night would have lured me into the darkness for one last pass on the trails before bedtime. But an early morning had already left me salivating for a delicious sleep to the tune of nighttime noises.
At my feet, frozen mid-stride in the light of the back porch, a small and muddied, wide-eyed bug paused on the concrete slab.

Not an insect drawn to light, he stumbled clumsily along on over-sized forelegs more suited for digging than walking and with a rounded profile that gave him an appearance less like a beetle, more like a bullet—a very slow one—poorly aimed and off course to arrive beside my back door.
In the several seconds that it took me to stoop and scoop the dirt-clad vagabond into my hand for a closer look, I had already come to recognize just what he was. The context was what, at first, had stumped me.

cicada nymph emergence hole in ground

By mid-summer, lifeless hulls of annual cicadas garnish every vertical surface around my yard—tree trunks, garden plants, even the cedar shakes of the house. In their metamorphosis from subterranean, root-feeding nymphs to noisy, sap-sucking songsters of a heated afternoon, these large, loud relatives of tree hoppers and aphids emerge as adults, leaving behind translucent shed skins, still holding fast with clawed feet to their upright post.

molted skin of cicada adhering to tree bark

The molted skins, split up the back and empty of their residents, are as common by July as the day is strong with song.
And, though I find their small exit holes scattered between blades of grass across the lawn, I’ve never found a nymph alive and walking—trundling in the dark from a life underground to a winged life in the sky.

He sat barely moving, caked with clay in my curled hand, deep shades of green peeking through the golden brown shell where dirt from his underground passage had been brushed bare. Then, stepping past the laundry basket and off the well-lit porch, I carried him into the darkness of the yard and set him at the base of Mother Maple.

cicada nymph scaling tree
11:43 pm

Slowly and steadily he climbed to a lichen-covered knob of bark on the old, trusted tree, his heavy body seemingly quite a challenge for legs that lift little, knowing only a life underground.

12:18 am

Then, from the dirty, dusted shell, a peek of color as his newly-minted form emerged—an emerald-trimmed body with still-curled, turquoise wings, a face studded with 3 spots of gold, 2 widely-set eyes of jade.

12:19 am
See the 3 spots of gold in the center of his face?
They're tiny additional eyes (ocelli) which lie between his larger, widely set eyes!


12:23 am


12:30 am


12:32 am


1:07 am





"Have you seen...." is an effort to discover the unusual beauty in things not usually appreciated for their beauty.

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Monday, June 20, 2011

Hope... and things with wings...from a naturalist's notebook

January 18th was a day for winter walking.
Light rain mid-morning had given way to blue skies, which, in a season best described as a string of predictably gray flannel afternoons that stretches from November to March, was in itself reason to make note. But in the woods where I stood looking up, admiring the unusual brilliance from beneath a tangle of bare limbs, I discovered something even better--a small package tethered to a branch. Just above my head, encased in the barest brown wrapper and tied to the very tip of a twig at the furthest reach of slender arm off the large maple, was the cocoon of a Cecropia moth.
Gently, I broke the twig free and its small brown package, tucked into my pocket.
Beneath the date in my notebook, I wrote, “Cecropia cocoon!”

The Cecropia moth, Hyalophora cecropia, is the largest member of the Saturniidae family native to North America. Giant silkworm moths, whose members also include the Luna and Promethea, emerge in the spring from cocoons left to overwinter by last summer’s 5-inch long, ravenous caterpillars. Constructed inside a covering of leaves which falls away in the winter weather, this strong silken pouch, within which the transformation takes place, is seldom seen against the backdrop of winter’s brown and gray.

On my back porch, I carefully propped the prized cocoon against one side of a small, glass tank and secured the lid. From there, while winter’s temperatures moved the cocoon slowly toward an eagerly awaited spring, I could easily keep an eye on any change.
But could I really?

•••

April 1st brought with it a series of doubts.
Had I been correct in my hasty assumption months ago that this was really a cecropia cocoon?
And if so, was it even still alive? There was no way to see beyond the leathery brown wrapper. Perhaps the silken sac was years past holding anything viable.
Had my high hopes steered my perception to the point that I was now guarding an imagined treasure that would turn out to be nothing at all?
Had I fallen to nature’s trickery on this day of jokes and pranks?

The Cecropia spins a 2-layered cocoon--
a leathery outer layer which fits loosely
and a dense inner chamber inside which he pupates.
Added all up...4000 to 5000 feet of silk!

In the sunshine of the front stoop, I slowly opened the small package. A fine pair of scissors and steady hand made only the least slit necessary through which to steal a glimpse of what treasure might lie inside. Beyond the silken pouch was another—a fuzzier encasement more obviously oval, more shaped like the fat, squat body that I had hoped to find. Gingerly, I peeled back just the very end of it, taking care not to squeeze or bruise the precious contents in any way.


I tipped it out onto my hand, and there he was…revealed in sunlight, the dark-clad form, perfect face, plumose antennae, forelegs folded, his still, unfurled wings…patiently waiting.

Look!
Abdominal segments to the left, folded forewings to the right,
and antennae wrapping his face!
It's a boy!


In the warmth of my hand he turned, spinning circles with his abdomen as one would spin to keep a hula-hoop aloft.
Yes, there was life in this plain brown wrapper—life yet somewhere between caterpillar and moth.

Exactly as he had been, I put him back.
With a needle and thread, I drew closed the opening in the fuzzy, oval case, then set it back inside the silken pouch. A papier-mâché patch sealed it snuggly shut.



•••

June 8th began as a day like any other.
By now, at 142 days of waiting, each pass I made across the back porch, whether coming or going, had evolved into an elaborate sort of curtsy at the back door. With one hand on the doorknob, I bowed and peeked below the lid of the glass tank to be sure the moth hadn’t yet emerged to rest unseen on the underside of the lid.
It had been a long and slowly passing spring.

By noon, I left to run errands. The day warmed vigorously, the air becoming heavy and heated beneath strong sunshine as the afternoon hours unfurled. With a load of groceries, I returned home, strode up the walk and paused to curtsy beside the back door.


Broad, fresh wings fanned slowly inside the tank. Already spread to their full 6-inch span, they pumped strongly and steadily, back and forth, their water-colored rims just barely dimpled.


Furry forelegs held fast to the tip of his makeshift branch. Released from their dark wrapper, his antennae stood proudly like plumes above his perfect face.


And for the first time, I saw a tiny eye--all that is needed by one who will be guided by scent, and who patiently waits for nightfall…to fly.




Scales covering the forewing are actually modified hairs

Cecropia moths emerge from their cocoons through loose valves at the end. Once free, they hang to inflate their folded wings, using a pumping action to press lymphatic fluid into them from an oversized abdomen. Living only a brief 7-10 days, cecropia moths have no mouthparts and are unable to feed. Their sole purpose in this time is to complete the reproductive cycle. Sometimes flying more than 7 miles, males locate females using their more developed antennae to pick up her scent (pheromones) in the warm night air. Cecropia moths are univoltine—in the course of a year, only one breeding cycle takes place. Eggs left by the female will hatch this summer, feed as caterpillars and pupate to overwinter within a cocoon and emerge next spring.
Squirrels sometimes eat overwintering pupae.
Tree trimming may be detrimental as well, as cocoons are fastened to the outermost ends of branches.





Hair-like receptors for detecting odors line his antennae...look closely!

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Sunday, August 24, 2008

Poor Literacy Skills and Mathematical Ability in Butterflies

Black Swallowtail Butterfly wing scales

I’ve never written an article for a scientific journal or, for that matter, any other serious piece of literature, but from time to time, the discoveries made in my laboratory (the kitchen table) seem worthy of mention.

Take, for example, the Black Swallowtail chrysalis I had been watching for 13 days, every morning noting color changes, as it hung suspended from a vase of flowers in the center of the table. For much of the 2-week span, I had returned it to a spot in my garden, hoping the humidity and temperature outdoors would be most like its natural setting. Only at day 9, did I bring it indoors, and prepare to capture the emergence with my camera.

The internet is full of caterpillar raising guidelines, a manual of sorts, as the metamorphosis of Black Swallowtails is both educational and inspiring to witness. And my hope to catch it “live,” on a weekend day while I would be home, seemed realistic. By the end of last week, the chrysalis had begun to darken.

Timing is everything.
And being prepared to record an extraordinary event meant a little more homework and a plan.

Consulting the manual, I learned that once the color had changed from brown or, in my case, green to black, the emergence would soon follow. Behind the now translucent cover, the details of the large black butterfly within had become visible.

Before bed last evening, I recharged the battery, cleaned the lens, and chose a spot outdoors with good light. The forecast for the next morning was perfect.
I would easily be ready by 10:00 am—the time most butterflies emerge.

We wake early, and enjoy fresh coffee at the kitchen table and laptops until sunrise. The darkened room makes photo editing easy—a quiet world, less distracting. In the center of it all, the chrysalis, still black, just inches beyond my open screen. Camera, at my side, I watched. With every warm sip, I waited, becoming increasingly convinced that all accounts of a 10:00 arrival would be, indeed, accurate.

One last check of email, just a minute’s lapse…
And I missed it.
8:15 am--the most important moment in his life.

I have concluded that this demonstrates one or both of these possibilities:
1. Butterflies cannot read.
2. Butterflies cannot tell time.


All photos enlarge with a click








Newly emerged Black Swallowtail on Ironweed



Empty Black Swallowtail chrysalis

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Wednesday, August 13, 2008

Metamorphosis

It’s that time of year again. When they dust off the school buses, and the elementary building up the road begins to show signs of life once more.
It is time to go back to school.

I remember first-day jitters and my favorite lunch box. Kickball and the Pledge of Allegiance. And of course, hoping my desk would be close enough to the window ledge to be able to watch the caterpillars in glass boxes.
There were always caterpillars on the first day of school.


I found a small Black Swallowtail caterpillar on Queen Anne’s Lace in the field, recently hatched and still wearing his white saddle. Days later his plump green body nibbled hungrily beneath another umbel--the changes already beginning.


I snipped several stems of his favorite and carried them with me, home. A small glass vase keeps them fresh, as he eats and eats …and eats on our kitchen table.





Black Swallowtail caterpillar tethered to Ironweed

A day of stillness brings another change.


This time, his lovely chrysalis tethered by thin silken strands where his striped body hung the night before, as a newly furled leaf along the stem.


Shed caterpillar skin like a bunched up sock beneath him.
Faint lines upon green, trace the life changing within.


I see wings and eyes on a butterfly’s face.


Metamorphosis, a beautiful form evolving from behind the thinnest curtain, a child’s lesson never old.
A wonder of life to witness, each time, new.

Black Swallowtail chrysalis on Ironweed


Click photos to enlarge
Can you see his face and wings?




Shed skin showing head capsule

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