Monday, February 28, 2011

Winter Stonefly's Snowy Scurry

Today was a good day for the winter stoneflies.  They were scurrying all over the snow in search of mates.

Small winter stonefly    Capniidae
There were at least two different kinds climbing all over the yard, the picnic table, and the house.

Winter stonefly        Taeniopterygidae
  You'll remember I posted about the snow midges which have the same ability to be out and about this time of year.  If I would crawl across the snow like that, I'd have frost bite in a jiffy.  I am almost jealous of their cryoprotective (anti-freeze) compounds.  That ability is supercool!  I've used supercool as an expression before, but it is a word that basically means cooling below the freezing point without freezing.
   Of course, there is more to the life of a winter snowfly than running around on the snow.  These guys are freshly "hatched" from their aquatic larvae.  They were formerly a part of the benthos and occasionally they went driftin'. Since they hatched, it means they survived the Driftin' Diner.  I should clarify that the stonefly nymphs were part of the benthic drift I posted about, but the stonefly adults were riding rafts or climbing on shore. These nymphs hatch after climbing out of the water, as compared to some other insects like midges and mayflies, that hatch on the water.

Winter stonefly nymph
   These stonefly nymphs live on the stream bed, shredding leaves or CPOM (coarse particulate organic matter) for food.  Some of them may graze on periphyton as well.
   When their shredding days are accomplished the nymphs are ready to be delivered from the benthos.


Stonefly nymph exoskeleton
  The stonefly nymphs crawl out of the water and onto some object like a log or a rock.  Shortly, their exoskeleton splits open down the back and out crawls an adult stonefly.

Then comes my favorite part.
 I'm thinking about a satellite unfurling its solar panels once it reaches orbit.

 Just think

 of the engineering

 and "computer programming"

 necessary to perform this unfurling of wings.

Well, there you have it.  A mature winter stonefly.

Small but sophisticated.


More to explore:

Friday, February 25, 2011

Snow Midges

  The other day when I saw the Mallards feasting on the benthic drift being carried along in the strong current, I decided to investigate a nearby stream bank and see what hatch might be happening.

I wasn't disappointed, for as you can see, the stream bank was lined with multitudes of midges. 
 You could pass off the stream bank as dirty snow, but it was actually pure white snow covered with winter-emergent chironomidae (snow midges).   

 Somehow the view in this picture made me momentarily think of Pickett's Charge.

Mostly I had to think of the magnitude of what was on display there.
Snow Midge
    First, I had to think about the midge's cold-hardiness, which is a survival mechanism enabled by cryoprotectants. That's a big deal for such a tiny critter
Also the chironomid life cycle came to mind.
 Here is a midge larva in a drop of water.
 These midge larvae live on the substrate of cold flowing streams eating periphyton or detritus.

This larva made a great subject for my second attempt at microphotography.
 Here is a microscopic view of a larva clinging to a bit algae with its short proleg. Notice the dual eyespots.
  Here is a microscopic view of the terminal prolegs and brushes.
The larvae mature as pupae then float to the surface and hatch. The other day must have been a big hatch because the ducks were going crazy feeding on the drift. I'm assuming the current was full of midge pupae and exuviae. I should have tried to catch some of those pupae or cast pupal skins with my kick-net
Back to the life cycle, those matured larvae hatch and emerge from their pupae as cryoprotected adults ready to fly, mate, and lay eggs.
  " Talk about complete metamorphosis".
Those flying adult midges even come complete with "gyroscopes" which are really called halteres.  You can see them in the picture above (look like knobs on stalks)  located under the midge's wings.

Those little aquatic "worms" that live on the slimy stream rocks come out onto the snow ready TO FLY!
Just an ordinary day along the stream bank, eh?

More to explore:

Wednesday, February 23, 2011

Driftin' Diner

Yesterday was no ordinary day for the Mallards.
 With their necks outstretched, they paddled hard into the current.

 Then with desperate power turns they would snap up their driftin' dinner.

 No, there was no dabbling for the ducks yesterday because a benthic drift smorgasboard was being served up at the Driftin' Diner.

 So what was in the drift to defer their dabbling?
I waded into an eddy to let the current bring me a sampling.


 Stonefly nymphs.

That was my sampling of the Driftin' Diner menu.

The Diner was apparently open most of yesterday, but today the Mallards are back to dabbling for dinner along the shore.
More to explore:

Monday, February 21, 2011

Spring? Don't get used to it.

   We had a few days of warm springlike weather.  Folks around here were talking spring.  Of course some of us said "yep, its nice, but don't get used to it"
I did photograph some evidence that winter was losing its grip.
 The 'Scootac is free again.  Free to babble again instead of murmur.

 The jaws of winter lost their icy grip.

 The ice went out of our rivers and streams over the weekend.

 The sun was hard at work pulling back the blanket of snow.

 You could see an almost forgotten world being revealed in the melted rings around the tree trunks.

 Since snow reflects sunlight so well, the melting happening here was caused by the darker objects absorbing the sunlight and radiating heat into the snowpack.

 Bit by bit, around this twig, around that tree, and around that leaf, the snow was leaving. 

The sun almost had the snow blanket pulled back,
but it snowed 8 inches last night, so the winter world is still here.

 The snow is still boot deep.
 Hiking might still be easier on snowshoes.

There was talk among our family about going canoeing soon.  I think its best if we leave the canoes buried.
 Spring?  Don't get used to it yet.  It's not quite time to hang up the snowshoes.


 More to explore:

Thursday, February 17, 2011

Hackberry Haven Hotel

There are insects hidden in plain sight on this hackberry. 
   These insects are overwintering inside the hackberry petiole galls. 
    As I drive down the road and notice the hackberry trees covered with galls, I like to think of them as a chain of hotels called "Hackberry Haven Hotels".  The reason I call them hotels is because the galls contain numerous compartments. I have found up to six nymphs spending the winter inside a gall, each in their own white wax-lined "room".

   In this picture you can see some of those galls on a hackberry that is growing at the edge of the woods behind the wood pile at a place we call, "the Landing". 
    In order to make the Hackberry and its galls less inconspicuous and make it stand out from the brush, I used a camera flash in the dark.  Similarly, the hackberry gall psyllids are rather inconspicuous but there are four outstanding things about them that I would like to spotlight.

Hackberry Petiole Galls
    First, the hackberry petiole gall is caused by an insect named Pachypsylla venusta. In other words, the gall insect has information encoded in its DNA that gives it the ability to induce the tree to grow the gall.  The gall provides a food source and a sheltered home for the developing nymphs.
    The second thing that is worth noting is how the psyillid manages to live on the nutrient-poor tree sap. To round out its diet, the psyllid has a symbiotic relationship with endosymbiotic bacteria. The psyllid's DNA has a "computer program" that grows a specially designed structure called a bacteriome where its symbiotic bacteria live.

Here is a macro photo of a last instar nymph standing on the edge of its gall.  Note the white wax-lined compartments visible on the right
       The third item of note is the nymphs overwintering ability. When I opened up a gall one very cold winter day (near 0 F.) the nymphs were squishy(unfrozen) and in minutes were walking around.  I'm guessing the nymphs avoid freezing by producing their own antifreeze.  That's super cool.

A Microscopic Hole-saw
   I took the photo above by attaching my DSLR to my microscope which is similar to this one.  This a first for me, so stand by for more microphotography! 
   The fourth thing I'll spotlight is that the gall psyllid nymphs have an almost microscopic hole-saw that they use to cut escape holes out of their woody galls. They saw the holes by "wagging their tail".  The very first psyllid must have come with DNA instructions for forming teeth on the tip of its abdomen, otherwise it could not have gotten out of its gall, thus turning its gall home into a wax-lined coffin.

  The escape hole with a pencil tip for scale.

So, after all that gall growing, symbiotic sap sucking, waiting out the winter, and tail wagging, look at what shows up in the spring to start the process all over again. 
The adult hackberry petiole gall psyllid, which looks like a very tiny cicada.
Adult Hackberry Petiole Gall Psyllid, Pachypsylla venusta.

The Creator that wrote those DNA instructions packed some amazing abilities into that tiny creature.
I'm impressed.
 There is more going on at Hackberry Haven Hotel than meets the eye.

More to explore:
  • A website on the Hackberry gall psyllids and other pages about insects.
  • news release about the insect's symbiotic bacteria.
  • An MP3 on symbiosis from Institute for Creation Research.