Wednesday, January 9, 2013

Snow Fleas (you read that correctly)

Cedar Bog, snowy and dormant on a cold winter day. I had a meeting in Dayton last Sunday, and took the opportunity to make a quick stop at "the bog" (which is actually a fen) on the return trip. It's always good to become familiar with various habitats at all seasons, so I popped in to Ohio's favorite fen to make a few wintertime photos and a circuit of the boardwalk.

The famous Y-split in the trail, which was blanketed by several inches of snow. As I paused here to compose an image, I was surprised to spot a small spider balloon by on a silken strand. The arachnid siphoned off my attention, and I paused to watch the animal swing over to a sapling, alight, and slowly clamber up the branch. This made me recall an exchange that I'd had a few days before with Jim Dolan, about the various insects and spiders that can sometimes be rather plentiful in snowy wintertime woodlands.

Seeing the spider reminded me to peel my eyes for one of the strangest insectlike animals of winter, so I shifted from landscape mode to macro mode.

Boom! Not eight feet from where I saw the spider, the crystalline surface of the snow appeared to be dusted with pepper. Snow Fleas!

They may be small, but Snow Fleas rank high on the scale of intriguing "bugs". When I made these photos, the air temperature was 31 degrees and the "fleas" were hopping about like Mexican jumping beans. This find was just too good to pass up photographically, so I galoshed my way back to the car and rigged up the macro lens and flash unit. Upon returning to the scene of the fleas, I threw my coat down on the boardwalk to serve as a snow blanket, and prostrated myself before the tiny animals. These arthropods measure only a millimeter or so, and are too wee for even Canon's very competent 100 mm macro lens. I did the best that I could, and thought expensive thoughts regarding this BIZARRE LENS.

Snow Fleas, of course, are NOT fleas at all. They will not hop on you or your dog, bite, or otherwise annoy you in any way, shape or form. These curious critters are springtails, in the Class Collembola. And they're not  technically insects, although they once were placed in the Class Insecta. Apparently there are two species in these parts, both in the genus Hypogastrura, and I believe this is H. nivicola. We'll just call 'em Snow Fleas. They're referred to as springtails because of a barlike appendage on the animal's undersurface that is held under tension. When suddenly released this bar snaps the springtail high into the air, in a rather out of control fashion.

So why are they hopping around on the surface of the snow, on a subfreezing day? Good question. Snow Fleas are decomposers, feeding primarily on decaying leaf litter and apparently are active throughout the winter, snow or not. For reasons unclear to me, they are well known for their habitat of massing atop the snow's crust, as seen in these photos.

Scientists have looked into the physical mechanisms that allow Snow Fleas to operate in the dead of winter. Their bodies are infused with a glycine-rich protein - an antifreeze of sorts. Apparently Snow Flea protein is utterly unique, and is being studied for possible synthesized spin-offs that could have utility to humans, such as cryo-preservation of organs.

Snow Fleas are common enough, and if you find yourself traipsing around a snowy woods, keep an eye out for the Lilliputian beasts. They're easy to miss - from afar or even near their collective masses look like niger seed sprinkled across the snow. They often seem to collect around the bases of trees or along logs.

After watching the Snow Fleas for a while - there were probably thousands - my thoughts turned back to that cold spider that I had seen. I wonder if it, and perhaps other predators unexpected in winter's midst, remain active and prey on the "fleas".


Lisa at Greenbow said...

I have heard of these little beasties but I have never seen them before.

Sharkbytes said...

Gotta love 'em. I did a post on them at

zippiknits said...

I'm agog. Snow Fleas. My grandmother used to tell me they were out there in the snowy Ohio woods that backed into my grandparent's farm, but I thought they could bite. lol She wanted me to stay out of those woods, me thinks.

Jim McCormac said...

Thanks for your comments, everybody, and very nice post and video Sharkbytes!

jaredmizanin said...

Very interesting...will have to keep an eye out for them now. Good question on whether or not the spiders would actively prey on these fleas. I'm wondering how the digestive system of a spider might work, and if the process of digestion would take too long in the cold weather.

And if you think the mp-e 65mm is expensive, consider the fact that you'd likely end up shelling out another few hundred bucks for a ring flash to use with it!

Jim McCormac said...

Just got the ring flash Tuesday, Jared, and can't wait to put it to work!

Emily S said...

A question: If these critters are not technically insects, what are they?

Jim McCormac said...

Hi Emily. Springtails were once placed with insects- Class Insecta- but are now usually placed in their own Class, Collembola. Type springtail into Wikipedia; its got a pretty good explanation.