Tuesday, February 12, 2008

Fighting Collembola!

Rainy day bug blogging:

If I can't get outside because of the weather, I can always bring the outside in. I went to the edge of the garden and collected a cupful of topsoil, brought it in and inspected it.

It's still too cold for baby slugs and spiders, but the springtails were swarming. I popped them under a bright light and aimed the camera at them.

Aren't they cute?

This family of springtails, the Onychiuridae, doesn't spring. Most springtails have an appendage at the tail that they carry clipped underneath the body. When they release the bond, it snaps back, popping the owner high into the air. These little guys don't have one, so they just run about.

They are also blind and colorless. (In the photo above, the white balance is off, but I didn't correct it because they became so bright that the segments weren't visible.)

No eyes.

Lack of vision doesn't seem to slow them down any. When I disturb the soil and other tiny soil residents make themselves scarce or freeze in place, these Collembola keep on going, around and about, under and over, back and forth, ignoring me and my works.

And something weird; they float. They bounce up to the top of any amount of water like tiny white corks. Squirming corks, that is. They are unwettable, unsinkable.

I added a litre of water to my cup of soil, and poured it out into a shallow tray. The springtails clumped on the surface, all together, and could be scooped out with a spoon.

Here they are, on 1/2 inch of water.

On the water, the mass of springtails squirms, moving constantly, but with no grip on the surface, they just jitter from spot to spot. I video'd them at it; check this out:

video

These aren't the only Collembola in my patch of soil; the Entomobryidae show up sometimes. These do jump, and are not blind.

I was filming a handful of the Onychiuridae on a wet leaf, when a little brown springtail came around the corner. Cute little guy. But I was quite taken aback by what happened next. Watch this video; keep your eyes on the little dark one at the tip of the stick. The big white springtail that attacks him fights rather like a cat, and leaves the poor little one in tough shape.

(Blogger was driving me crazy tonight. It wouldn't accept the good copy of this video. So I loaded it onto my website; here. A blurry, dark, abbreviated copy, all that Blogger would allow, is below.)

video

Unfortunately, a couple of the beasties in this video are belly up, and others seem a bit disoriented. I had the hot light just a few inches away, and I'd been decanting them from cup to pot to tray to leaf; with that, even a springtail loses his oomph. Can't have that; I carefully put them back in the garden where I found them, with my apologies.

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6 comments:

Tim Eisele said...

They are cute. I need to get some pictures of the ones we have around here - there are a lot of the ones that have a metallic sivery sheen and definitely have the spring mechanism.

Wanderin' Weeta said...

Tim;

I wonder if yours float, or if that's a characteristic only of Onychiuridae.

Let us know if you do the test.

Hugh said...

That was great! The videos are fascinating.

I used to have a small pond in the yard, and several times found its surface covered in, I'm guessing, onychiurids. They were alive and mobile. I'm not sure what attracted them. Perhaps each other.


Hugh

Wanderin' Weeta said...

I was thinking about their floating abilities; I guess, in BC's climate, it's a handy trait. They don't have to climb to the top of the soil when it rains; they bounce. I'll be looking at ponds more carefully from now on.

Domingo Zungri said...

My take on this episode is that the small dark springtail and the larger white springtail, both of them blind, stumbled into each other by accident; this frightened the white one and caused it to secrete toxic defensive chemicals that irritated and disabled the dark one. A Google search revealed the following link which shows that some springtails secrete toxic chemicals for defensive purposes:
http://www.springerlink.com/
content/v45v47273643612n/
(I had to insert a break after ".com/" and "content" to get the link to fit.)

Wanderin' Weeta said...

Thanks, Domingo,

Very interesting!

The link, to make it a bit easier to follow, is here.

From the abstract: they tested the chemicals on ground beetles, and "the pseudocellular fluid evokes a total disorientation and cleansing behavior". The brown springtail was certainly disoriented!