Tuesday, October 30, 2012

A wasp hunkering down for the winter?

   I was examining a moss-covered, fallen log when I noticed an orange ichneumon wasp with a black head and banded wings.  I suspect this wasp, a Acrotaphus wiltii, was searching for its winter hibernation site.  I'm going with this theory, because this late in October, it seems too late for the wasp to be hunting for an orb-weaver spider to parasitize.
  I was down on my knees looking closely at this well-rotted log covered with moss when I saw this ichneumon wasp.  I was in a valley were the winter sun hardly shines. The lack of sunlight in combination with the thick moss covering the punky wood, makes the log a place where moisture would remain fairly constant.  There are various species of ichneumon wasps that choose localities like this for a place to spend the winter months.
   Contrast this old soggy log with the site where other species of hibernating ichneumon wasps (I wrote about last winter) were spending the long, cold winter under moss on rocks of ridge top.  Ichneumon wasps have a variety of settings for their hibernacula.
   The cool, late October weather was taking a toll on this wasp.  It groggily crawled along, allowing me to snap a few pictures.
This slender, orange wasp's body is about a half inch long.  With antennae and ovipositor, it measures about an inch.
The wasp didn't pose nicely for me, but did kindly display its translucent, black-banded wings.
I wonder if there are other ichneumon wasps hunkering down for the winter under the moss of this log?
There's a good chance... and the log holds many other marvels to sidetrack the hiker.

Monday, October 29, 2012

Imbricated

   This summer's low water is gone... now that the big storm, Sandy, has hit the area with lots of rain.  With the rising water, the lowest stream terraces will be submerged, and so will the ubiquitous pattern of the imbricated stream rocks that line the stream banks.
 This natural texture of the stream substrate is commonplace, unless the rocks are moved around by other causes, such as boys looking for aquatic life.
 Imbricated stream rocks are inclined toward the upstream side and stacked on the backs of the downstream rocks... somewhat like fish scales.
 In this photo the current is from the left.
 The other day, as I was stream walking, the afternoon sunlight accentuated the texture of the imbricated rocks.  I snapped a few shots.  The upstream side is to the right.
imbricated stream rocks
 You can see the rocks are all tilted the same direction... with their flat sides dipping upstream.
  This is the most stable position for platy rocks in stream flow.
imbricated stream rocks
 I looked through my files and found some photos where imbricated rocks happen to be visible.
This photo of a waterfall shows a definite pattern in the rocks surrounding the plunge pool.

Here the rocks are mostly submerged, but with the knowledge of this stream process, you can see that the rocks are inclined basinward.

Here is a photo of a stream bed with a little water trickling among the imbricated rocks.   It would take a much higher flow to mobilize the bed load in this streambed.
   Have you ever stood by a roaring, flooded stream and heard the clunking and booming of rocks as they were rolled along?  The sound of bedload transport in a rocky, mountain stream is an unforgettable sound.
   I suspect Hurricane Sandy will rearrange the bed load of our streams and rivers around here.  She'll probably "re-imbricate" some rocks that have been moved around by people and things other than stream processes.
Even if the imbricated rocks are mostly submerged, we know they are there!

Friday, October 26, 2012

If only this tree could talk... Part II

   I've been past this ancient, old-growth hemlock many times.  Somehow, I never thought about the tree being hundreds of years old, and that it witnessed a tragic event in 1864.
  The hemlock tree can't tell me whether it was one of the trees on which bodies were found.
   On September 10, 1864, the Westmoreland (a 4-4-0 Bury boiler steam locomotive) had just left the sawmill and was pulling the gentle grade out 'Scootac with 4 people on board the locomotive.
   This hemlock tree stood between the two railroad grades... the ill-fated locomotive was on the upper one, just out of sight to the right in the picture below.
    About half past 10 o'clock, and about a mile from the sawmill, the locomotive boiler exploded.  No one survived to give any details.  I'll spare you the gory details from the newspaper accounts of the aftermath.  I will say that the accounts give indication of shrapnel.

  There's a real good chance the locomotive, La Copiapo is a sister engine (same year, same builder) to the Westmoreland, so click here, here ,or here for a better idea of exactly how the engine looked.
Here is a photo of a model of a similar engine.  Well, one with a Bury boiler.

 Here is a photo of a boiler fragment from the Westmoreland.  It was found on the mountainside across the valley from the locomotive explosion.
  I have found other pieces of the locomotive over there on that mountainside...
like the rusty piece on the left side of the photo below... probably part of the spring safety valve


 I theorize that the engineer was showing off to his passengers.... by keeping the spring safety valve from doing its job... just to show them what the old girl could do


 Unfortunately, that's one way to have a boiler end up as shrapnel.


   About a hundred yards or so from the spot where the boiler fragment landed there are some more old-growth hemlock trees.
 These hemlocks have a certain ancient look... rugged, scruffy, craggy.

This photo is looking past one old-growth hemlock toward the locomotive boiler explosion site.

   Until recently I didn't think about the trees that were in the way of flying debris from the boiler explosion. In light of the fact that I've found pieces of the locomotive boiler clear on the other side of the valley, I wonder how many trees intercepted shrapnel?
I'd love to piece together the story of the Westmoreland.  Since it happened almost one hundred and fifty years ago, there's not much to go on.
Just some widely scattered fragments, a few newspaper articles, and some silent witnesses.  I almost missed this one...

I realized I might find some clues when I saw the tree rings... a record of a long history.
Perhaps the hemlock has wounds from locomotive explosion... perhaps it bears silent record of that accident... If the tree does, I haven't seen it yet...but, I'm still looking. 
If only this tree could talk.
At any rate, it's a historical tree and that's how I get to weave some history into a nature website.

Wednesday, October 24, 2012

If only this tree could talk...

Sometimes you think of something when its almost too late.
I've passed this spot many times.  I remember this old, ugly hemlock tree very well.
 Now it's gone.
 But, I guess it took its logs laying there by the roadside for me to realize it was an old-growth hemlock.
It's an ancient tree... count the rings!
I wonder if this tree bears record of what happened beside it on September 10, 1864?
If only this tree could talk...
Part two coming soon!

Monday, October 22, 2012

A strange moth that lives in a bag

What's hanging out here?
At first glance it could pass for a pine cone...  or a well camouflaged cocoon...
bagworm case - looks like a camouflaged cocoon
... but on closer examination it turns out to be a cocoon-like silk bag covered with bits of leaves, needles, and twigs.  This is the bag, or case, of a bagworm moth larva.
cocoon-like silk bag of bagworm
    The Evergreen Bagworm Moth (Thyridopteryx ephemeraeformis) has a very unusual life-cycle.  The bagworm moth caterpillars spend their life in these camouflaged bags, dragging their decorated homes about as they feed.  The caterpillars enlarge their cases as they grow. The female Evergreen Bagworm Moths never leave their cases.
   Earlier this summer, a young bagworm was feeding on a young aspen in our backyard.
When I first noticed the small bagworm case, it was less than half an inch long.  As the summer progressed, the caterpillar added to the bag until it was over two inches long.
 The bagworm caterpillar fastened its bag to a twig and stretched its head out of its bag to feed.
(Excuse the photo, I took the pic through a mesh bag I had placed over the bagworm in order to keep it from wandering away.)
   Here is a photo of the fully developed bagworm larva's case fastened to a twig of our aspen tree.
Since this photo was taken late in the season, the caterpillar has already pupated.  This case likely containes a female moth...as I mentioned before, the flightless female moths never leave their own bags.
   Sure enough, when I cut open the bagworm's case, it contained what looks like a pupa.

Here is another picture of the pupa.  Notice how the bagworm pupated head down.
   Now, some references say the worm-like female bagworm moth lays her eggs within her case. Since I found no eggs, I cut open the pupal skin.  There were all the eggs, as well as some tawny hairs that the moth probably rubbed off of its body to help protect the eggs. I have the "head" to the right in the picture below.
I've read some places that the bagworm moth retains the eggs in her body, while others say the eggs are laid within the pupal skin.  I can see either scenario in these photo, although if the female left the pupal case, I found no exit holes.  Whatever the case, she was mostly eggs, eh?

The male bagworm moths are another story.
After they are finished pupating, they wiggle partially out of the bottom of the bag.  Then the pupal case splits up the back and the male moth emerges.
The males leave their pupal skin hanging out of the bottom of their old home.  Incidentally, this makes a convenient marker of which bags likely contain eggs.
Evergreen Bagworm Moth case (Thyridopteryx ephemeraeformis)
The male bagworm moths then leave their larval home and fly around... visiting the flightless females which are emitting pheromones to attract the males from within their own bags.
   Here is a photo of bagworm cases.  The one in the foreground obviously contained a male bagworm moth, while the one in the background likely contained a female.
cases of the Evergreen Bagworm Moth (Thyridopteryx ephemeraeformis)He's been out on the town....
... she never got to dance at a street light.

Saturday, October 20, 2012

Seek no further, there's a Nature Post around here somewhere

 I took this ugly photo of a fencerow corner because I saw a Nature Post here.
   The main focus of this picture is an overgrown hulk of a fallen apple tree.  This dead tree is obscured by a growth of vines, weeds, and saplings.  Since I was right there, I could examine the tree from different angles and see through all the extras to better determine what I was looking at.  A photograph doesn't allow a person to do that.  Therefore, in order to strip away the peripheral vegetation and to illustrate what I saw beneath the overgrowth, I sketched our subject.
   I normally use my camera for my nature observations, but it was kinda fun to dust off the sketch book. I guess this could look like a page from a nature journal.
   This next photo is taken from the other side of the downed apple tree.  Notice the dark, dead branches of the tree and a few apple saplings growing at the far left. (far right in the sketch).
 Eric Sloane described a "Seek-no-further" apple tree which was about like this one.
He says, on page 41 of  A Reverence for Wood"Resting on a bed of leaves and young shoots was the hulk of an old apple tree well over three feet in diameter.  It had fallen from old age, yet some of the branches which were still living when the old tree fell had struck into the ground and miraculously taken root to become offspring of the parent tree".
Eric Sloane continued to describe a tree similar to the one pictured here by saying,  "As the fallen trunk decayed, new apple saplings had rooted all about it, giving the appearance of a family gathered around a dead giant on his bier,  The old tree had dug its branches like fingers into the earth, a strange and striking sequence of resurrection."   Well said!
   This is just an ugly, overgrown, dead apple tree in the corner of a fencerow, but, I thought it was worth appreciating the tenacity of the tree.
   Besides, I too, have a reverence for wood... and trees.