Thursday, September 24, 2009

AUTUMN LIGHTS

The pinpoint of green in the driveway gravel stopped me in my tracks. I'd just rolled the trash toter up the hill to the roadside for the morning's pickup, and was on my way back down to the cottage when I thought I saw a tiny gleam.
At first I wondered whether it might have been a bit of glass or metal foil reflecting some light source. But what light? There'd been a thick cloud cover all day, and the low overcast had stayed around, wrapping the night in an extra-deep cloak of darkness. Any hint of moon or stars had been blotted out. I could barely make out the white areas of Moon the dog's fur from five feet away. A thick screen of leafy trees and brushy undergrowth blocked the back door's weak porch light from reaching the slope of the drive.
Had I simply imagined the green?
No, there it was again—though not quite where I thought it had been the first time. Then I saw another glimmer of green a few yards away…and a third, just the merest hint, coming from the grass bordering the drive. I thought then the light's maker had to be some sort of bioluminescent insect. Curious to know more, I retrieved a flashlight from the cottage and returned to the hillside.
Lightening bugs aren't the only insects around sporting bioluminescence—that ability to generate light by mixing chemicals in their body. While fireflies are beetles which belong to the family Lampyridae, another group of bioluminescent beetles belong to the family Phengodidae, the glow-worm beetles. I wanted to catch a specimen of whatever was giving me an emerald wink, have a close look, and maybe try and key the insect down to see what I'd found.
One thing for sure, whatever they were their gleam wasn't nearly as bright as the flash from a typical backyard lightening bug. Even given the intense darkness, you had to be within a few yards to see one emit its brief glow. Their light was soft and green—a green the shade of a fresh lime, or the tips of certain spruce needles in the spring. Plus the miniscule light was often partially obscured by a blade or grass or some other bit of debris. It took a minute or two to located a glow I could quick-follow to the source with the flashlight's bright beam.
Eventually I captured my prey—several, in fact. The creatures, while identical in appearance, did vary slightly in length—ranging from about 12mm to possibly 20mm. They were quite active and would crawl across the palm of my hand in a moment. I put them in an empty pill bottle and took them to the desk for further research.
I still don't know—at the specie level—exactly what I have, but I do know they are firefly larvae. They began life as an egg, deposited on or slightly below the surface of the ground, by the winged female adult a few days after mating; doubtless the offspring of a pair of those dancing lightening bugs that twinkled like fallen stars over the yard's lawn and bushes on summer evenings. Three or four weeks after laying, the eggs hatched into this larval stage.
Firefly larvae feed all summer and into the warmer weeks of autumn, before burrowing underground or beneath a bit of tree bark where they'll overwinter until spring. From what I've read, firefly larvae are predators, preying on small animals such as snails and slugs.
After making a few (not particularly good) photos, I returned the captured firefly larvae back to their chosen hunting territory and sent them on their way. Once my eyes had readjusted to the night, I stood for another quarter-hour, watching, as all around the brethren of my captured larvae turned their muted neon-green lamps on and off…tiny bioluminescence embers burning amid the rich darkness of the changing season.

22 comments:

Jenn Jilks said...

You're a good man.

Take only photos, leave only footprints!

Great shots. I remember only yesterday - it was June - when they were looking for love!

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Jenn…

I can't remember when I last saw lightening bugs in the yard winking in the twilight…but I don't think it was more than a few weeks ago. Sometime in August, for sure.

Thank you…

Debbie said...

We can learn something new every day if we try. Thanks for the information on this. I had absolutely no education on one of my favorites, fireflies. I did have a horrible experience once with something called a 'dobson fly'. Nasty creatures. These look peaceful and don't have pincers.
I wonder what I miss because I just don't notice OR I'm not out at the right time of day.
Debbie

Gail said...

HI GRIZZ-

Oh my, I learn SO much here from you. I know of the green luminescent bugs of which you write and pictured. Well, perhaps a cousin to it. the one that happened in here was a lighter green, like the color of snow peas and it glowed brightly and was a good four or five inches long with bent legs and large wings. I wqas actually scared of it - my husband covered it gently with a cloth and put it outside. It glowed in the dark night on the ledge of our upper deck. Eerie!!

I love your world and being able to visit you.

Love Gail
peace......

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Debbie…

Hey, I probably would never have noticed these glowing larvae if I hadn't had to take the trash barrel up the hill after dark because I forgot to do it earlier. Moreover, I didn't know what the insects were until I did some research—just knew they were bugs with built-in night lights.

I do know about Dobson flies, though—mostly about them in their hellgrammite stage. Hellgrammites are seined from rocky riffles in local streams and used as bait for smallmouth bass. They're common in the river a dozen feet from my front door. If you got pinched by the insect in its adult form, it was a female…the male's mandibles are much longer than the female's, but actually too long to be capable of pinching. I know this seems counter-intuitive. However, it's the gals with their shorter jaws that can achieve the real leverage and draw blood.

(Okay, for any of you out there who've just had a sudden urge to smirk…yes, I'm sure a male chauvinist could draw some sexist parallel from this odd entomological fact. We riverbankers are of better stock and raising, however—so let's just pass quickly along and not stoop to such sophomoric quips.)

Kelly said...

well...that first photo stopped me in my tracks, and then I was locked into your research! Very interesting and very cool...thanks for teaching me about the larvae of the little winking bugs of summer.

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Gail…

Well, you learned about this critter only hours after I learned about it—but I'm glad to share my recent education… or should that be enlightenment?

I have no idea what you might have found and placed outside, though. Actually, I know embarrassingly little about almost all insects—except for mayflies and caddis flies and similar trout fare (for piscatorial reasons, obviously) and the more common things we all know a bit about.

I am, however, trying to become marginally less ignorant about bugs before reaching my dotage.

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Kelly…

Not the best photo, but frankly, it shows about all there was to see on those larvae. (No, that's just an excuse; I could have/should have done better.)

Well, I didn't know enough about them to recognize one in my hand last night—just knew it was a bioluminescent larvae of some sort. I'm still learning, too…and there's a long road ahead. :-)

Bonnie, Original Art Studio said...

Oh - it's so hard - you bring out the sophomoric in me. But I digress.

A very interesting post. Feel like I'm attending a tutorial here - your knowledge of all things natural is boundless or so it seems to one as unschooled in this area as I.

Nice to visit a blog with lots of meat on its bones!

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Bonnie…

I bring out the sophomoric in me, too…along with the occasionally moronic.

My "boundless" outdoor knowledge is derived from a rather misspent life of doing my level best to avoid meaningful work by frittering away endless hours rambling woods and waters and back-of-beyond paths with a fly rod, shotgun, canoe paddle and camera—then trying to figure out how to get paid for it afterwards. But I assure you, what I do know is not even a drop in the bucket to what I don't know—much of which, I have yet to even suspect I don't know. (Ignorance is bliss! And there are many days when I'm mighty blissful.)

While I'm not sure this is meaty blog—I can absolutely assure you it is the work of a meaty blogger.

Jayne said...

Amazing find there!

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Jayne…

A neat, interesting bug, for sure—though I didn't so much find it as it gave itself away. Now it's on the blog! Seen by millions (well, dozens, perhaps.) Famous!

Yup, it pays to advertise.

Squirrel said...

Is this what they call a glow worm? I enjoyed reading your narative.

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Squirrel…

The answer to your question is one of those scientific hairsplitting deals—yes…and sorta yes.

Here's what I think I understand…

Among the various species of Lampyridae—the family name of the beetles we call fireflies or lightening bugs—many of the larvae and adults are bioluminescent. They can make their own light. In America, the glowing larvae are all called "glow worms." (That's the unadorned "yes" part of your answer.)

In many parts of Europe, however, a glow worm is a particular Lampyridae species of lightening bug larvae—not the collective. (That's part of the "sorta yes" answer.)

Now, to further muddle the issue (and finish out on the rest of your "sorta yes" answer) there is also a second family of beetles—the Phengodidae—which are collectively known as the "glow worm beetles." They also sport bioluminescence capabilities in both adults and larvae, and in their larvae stage are also called glow worms.

Hey, glad you liked the piece—and happy you wandered over to the riverbank. Hope you make it a habit. You're always welcome.

Bernie said...

Your intrest and research is amazing to me. I love visiting your blog Grizz, it is full of warmth and so eductational...: love and enjoy this lovely place you call home.......:-)Hugs

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Bernie…

And love hearing how much you enjoy visiting. I'm so glad you like the riverbank! Thank you.

Squirrel said...

Thanks, you have given me some things to look up. Always learning because it is so much fun! I'll definately be back. Drop over to Squirrel's View anytime. I love to share information.
Regards.

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Squirrel…

Hey, learning about the world around you is endlessly fascinating. I'm always curious about things. Insects are quite interesting, and come in all shapes and colors, with strange, complicated habits and features. Don't know whether you saw it or not, but a perfect example would be the post I did a few weeks ago…

(http://riverdaze.blogspot.com/2009/08/candystripers.html)

…on candystripe leafhoppers. They're about the size of a sesame seed and extremely colorful. Most folks have never seen one in their life, though they're quite common.

Incidentally, one of the best places I've found on the Internet to identify and learn about an insect (which you probably know already) is:

http://bugguide.net/node/view/15740

Anyway, glad you'll be regularly stopping by the riverbank. And I will, indeed, visit your place.

The Weaver of Grass said...

I love the idea of those little green lamps turning on and off Scribe - you are so lucky to have such creatures. That luminous colouring is so beautiful isn't it. Here we have Dor beetles and they have purple luminous parts which, if they catch the sunlight, are exquisite.

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Weaver…

I should have taken the time make a photo of one of these larvae "lighting up" their tiny green lamp. That would have been a neat shot.

However, unlike the insect in its winged adult "firefly" form, who keep right on flashing when captured, whether held in your hand or placed in a jar, these larvae never flashed a single time once I brought them inside. (In the larvae, it is really more a brief, soft glow; not nearly as much light—though a very pretty and intense green.)

To get a "lit up" shot, it might be necessary to build a natural "set" and wait for them to become comfortable. I just made a few shots outside, brought the larvae in for handy reference while I keyed them down and figured out what they were…then took them back out and turned them loose.

Which is probably just a long way of saying I got lazy…

Squirrel said...

Yes, I have seen the candystripe leafhoppers but didn't know that was the common name. During the summer lots of really cool stuff comes to my porch light. I went to your blog and enjoyed the great photos and write up. I can I have a lot of catching up to do on your blog. Thanks for the feedback.

The-Grizzled-But-Still-Incorrigible-Scribe-Himself! said...

Squirrel…

Hey, you're quite welcome. I'm glad you've found some stuff here you like. We're not much on pretension here, but we're big on hospitality…plus we generally try and have a good time.