Saturday, November 23, 2013

"Two-headed" caterpillar with black and white pinstripes

  Today I walked past a vine where back in early October I saw a caterpillar which looked like it had two heads.  Each end of the caterpillar looked like a black head with white spots.  The caterpillar, which is called a Turbulent Phospila (Phosphila turbulenta), has a whole lot of black and white pinstripes with a bit of yellow  on its sides just above its legs.
  Here is a photo of the caterpillar of a Phosphila turbulenta on a Greenbrier vine.  Notice the upper end (the fake head end) is swollen and has white spots and markings to make it look almost exactly like the caterpillar's real head.
Turbulent Phospila (Phosphila turbulenta) on greenbrier vine
     A head on each end... I wonder if bird's brains can figure out which end is up?  I suspect a fake head could give the caterpillar a fighting chance should a bird choose to peck its hinder end instead of its head.  I wish now that I would have acted bird-brained and "pinched" the wrong end just to see if this caterpillar was chemically defended in some way.  As smartly colored and brightly patterned as the caterpillar is, I suspect it is chemically defended and therefore distasteful to birds.  It follows that they have little need to hide... perhaps that is why I spotted the caterpillars as I was walking trail.
   The photo below shows another Turbulent Phosphila caterpillar that was feeding on a leaf elsewhere on the same Greenbrier vine. 
caterpillar of Turbulent Phosphila feeding on greenbrier
In fact, there were many of these gregarious caterpillars scattered around on the Greenbrier vine.  When the caterpillars were young they would have been feeding on the Greenbrier in close proximity to each other - feeding in groups - probably for safety in numbers.  As they grow they must wander off on their own, at least on their preferred host plant, the Greenbrier.

   I encountered these black-and-white striped caterpillars back in October.  Now, in late November with winter fast approaching, what are these caterpillars doing?  Well, in the leaf-litter on the ground nearby a Greenbrier vine you might find a withered, lumpy, folded-over leaf that feels a bit heavy for a dried leaf...
In the photo below, you can see I pulled the leaf slightly apart to reveal a pupating Turbulent Phosphila.  Within the enclosing leaf the pupa was encircled with a ring of silk and "junk" which formed a "cell" or partial cocoon.
pupa of Turbulent Phosphila
Barring unfavorable environmental conditions, predators, or parasites, that pupa should turn into a rather nondescript, camouflaged, grayish-brown moth come spring.  I think I have a photo of one of these moths that I had taken last spring but can't seem to find it... too plain-looking, eh?

   On the same Greenbrier vine as these caterpillars I also noticed a little pile of trash that was moving... there was a tiny trash collector sidling along the vine.  Can you tell that I, like always, didn't get very far on my nature walk?  Oh well, that little creature will make the subject matter of my next post and so we will continue this nature walk/field trip on a vine with tiny camouflaged trash collectors hiding out nearby where flashy, pinstripe-wearing "two-headed" Turbulent Phosphila caterpillars are feeding contentedly.
 

Wednesday, November 20, 2013

A Fallen Leaf Story

I reckon a fallen leaf can tell a story.

   When I saw a Catalpa leaf that had fallen in our yard, I was reminded of a phenomenon that happens during the summer.

Can you see what I saw?  Can you picture what happened on this leaf last summer?
dark spots are extrafloral neactaries on catalpa leaf
   See those dark spots along the midrib or main veins of the leaf?  Those spots are the extrafloral nectaries on the catalpa leaf.  During the summer those nectaries attract quite a variety of insects.  I can see them now.... Ladybugs, little iridescent bees, ants, yellow jackets, and so on.  Why does a tree attract these insects to its leaves?  Well, many of them are predators and while they are hanging around enjoying the nectar on the leaf they might encounter some caterpillars or other insects that are feeding on the leaves.  I went into much greater detail in an earlier post about the extrafloral nectaries on catalpa leaves.
   I reckon that fallen leaf, with its outstanding spots, reminds me of how lively a place it was a few weeks ago.

BTY, last fall I wrote a post about another fallen leaf... an aspen leaf with a cute little stem gall.

Saturday, November 2, 2013

A Fall-blooming Orchid

   We were driving down a forsaken stretch of dirt road recently when I spotted some ladies'-tresses orchids that were growing by the side of the road.  I exclaimed to the boys, "Hey, orchids!" as I slammed on the brakes and backed up to have a look.
Yes!
Ladies'-tresses orchid - Spiranthes sp.
   Yes, there they were.... a couple of ladies'-tresses orchids with their spiraling spikes of small white flowers.  After getting out and exploring the vicinity, we found quite a number of these orchids growing on a wasteland of old stripping piles through which the road had been cut.
   Here is a photo of my camera and tripod set up to take photos of the orchids. 
   There's not much of a road.  Perhaps it's good it was practically an abandoned road, for a few yards down the road, I knelt to take some of the photographs and to take in the faint, pleasant scent of the orchids.  I wish I could describe their sweet scent.

Ladies'-tresses orchid - Spiranthes sp.
   There are many species of ladies'-tresses and they are hard to tell apart.  I think these might be Yellow ladies-tresses (Spiranthes ochroleuca) because of the habitat where they were growing and the time of year they were blooming.
Ladies'-tresses orchid - Spiranthes sp.

A ladies'-tresses orchid pollination system.

   You may know that I am fascinated with the variety of pollination mechanisms that orchids employ to insure cross-pollination.  These particular ladies'-tresses orchids are no exception, so I might as well share with you, my worldwide readers, what I pointed out to the boys (and others).
   First, notice how the flowers spiral up the stem.  The lowest flowers on the spike open first, so the ones further up are 'younger'.  As the flowers 'age', the internal structure of the flower changes and they effectively turn from male flowers into female flowers. That means the younger, male flowers are near the top of the spike.
Now, let's picture how that works to help insure cross-pollination.  Generally, the visiting bees (bumble bees) will work their way up the flower spike... thereby visiting the older (female) flowers first with pollen from another ladies'-tresses.  Then, when the bee visits the higher, younger, male flowers, some pollinia are strategically lurking where they can be glued to the bee's probing proboscis.... to be carried away to another ladies'-tresses growing elsewhere.

I labeled the orchid's pollination system in this photo of a cross-sectioned orchid.
ladies'-tresses orchid pollination
   In a young flower, the viscidium (basically a strip of glue) is positioned close to the 'throat' of the flower where it will easily come in contact, and adhere to, the bee's 'tongue' as the bee sips nectar.  The viscidium is connected to the pollinia, or packages of pollen, as a way to attach the pollinia to a transport mechanism.
   As the flower ages, the viscidium grows farther away from the 'throat' of the flower (more out of the way) and the stigma is better exposed to contact from pollinia from other flowers.
  Simple, yet genius!
ladies'-tresses orchid - Spiranthes sp.
   These ladies'-tresses orchids may have been growing in a forsaken location, but now perhaps, they have been appreciated all over the world.  How cool is that?  I guess that's what happens when a blogger sees an ingeniously designed ladies'-tresses orchid growing by the side of the road. 

Monday, October 28, 2013

More Deer Sign In The Pokeberry Patch

Have you ever seen deer antlers stained pokeberry purple?
   When we saw plentiful deer sign in a pokeberry patch recently, we were a bit surprised to find that deer seem very fond of using purple pokeweed stems for buck-rubs.  Besides seeing evidence of deer browsing on the poisonous plant, we noticed numerous buck-rubs on the purple stalks.
   We would have liked to see a buck running around with purple-stained antlers. 
   The pokeweed stalks are about the same size as the saplings that bucks normally use for "buck-rubs", however, the stalks are much 'fleshier' and not near as sturdy.  We have tried to think of any other explanation for the 'buck-rubs' but haven't been successful.
The photo below shows a closer view of a pokeweed stalk showing evidence of the antler bashing the stalk received.
Buck-rub seems to be a good explanation, eh?
   Thinking along those lines, I tried to simulate a pokeberry purple-stained antler by rubbing a stick on a pokeweed stalk... see this stick in the photo below.
Maybe pokeweed stalks give the deer a gentler rub....
Maybe, just maybe, the deer use the stalks to apply war paint...

Thursday, October 24, 2013

Pokeweed Deer Browse

   We are sitting in a patch of Pokeweed watching for wildlife.  We saw plenty of deer sign here among the pokeweeds and realized that deer had been browsing extensively on the Pokeweed.
Pokeweed or Poke Berry
    Now, Pokeweed, or Poke Berry is a poisonous plant.  We were somewhat surprised to see the evidence of this unusual food choice.  We reckoned that the deer add them into their diet just to spice up their life because the patch of pokeweed is in the middle of a field with plenty of grass to feed on.  Not only that, but the field is surrounded by an oak forest with acorns galore along with every other kind of deer browse.
   Here is a photo of pokeweed with sign of deer browsing in the upper right of the photo.
Sign of deer browsing on pokeweed

Here are two more photos of the poke berry stems showing signs of deer browsing.
deer browse on pokeweed

Deer browse on poke berry
  Perhaps if we wait long enough, we'll see some deer feeding on the pokeweed and I'll be able to snap a picture of the deer adding a bit of 'zing' to their diet.
  See evidence that deer used the pokeweed stalks for buck-rubs.

Monday, October 21, 2013

Surrounded by Maggots

   My boys and I were hiking along a woods-road the other day.  When we sat down for a rest, one of the boys pointed out a "weird caterpillar".  I pointed out that there were more around us.... we were surrounded by 'maggots'.  Really, it wasn't that bad, because the larvae we saw looked more like odd-looking caterpillars rather than maggots.  What we saw were flower fly larvae (Syrphid sp.) which are also known as hover flies. 
   Here is a photo of one of the many flower fly larvae we saw on the forest floor.
Flower fly larva - syrphid sp.
I suspect these flower fly larvae may have made their way to the ground in preparation of pupating.  The flower fly larvae were 'crawling' on fallen twigs and leaves in their unique way.  Also, they have this habit of swinging their front half around like an elephant's trunk.
flower fly or hover fly larva
Here is a video of a flower fly larva as it 'crawls' along. 
video

Some flower fly larvae are know as 'aphid killers'.  
flower fly larva feeding on aphid
The ones we encountered there in the woods were obviously predatory larvae, since I noticed that some of them were preying on Giant Aphids.

Flower fly larva - syrphid fly larva
About the larvae, one boy said,  "They are not exactly maggo-nificent", but since it seems we are surrounded by maggots, we might as well take note of some of them...
I think I'd rather be surrounded by hover flies.

Tuesday, October 15, 2013

Squirrel Eating Leaves. Seriously

Who has been stripping the leaves from our Daisies?
You probably won't believe it, soooooo, here's a photo showing the leaf thief.... and, yes, this is a photo of a squirrel eating a leaf.
The squirrel pulls off a leaf and eats it stem first.  Nibble, nibble, nibble... in goes the leaf, stem-end first... nibble, nibble, nibble right down to the leaf tip.
Seriously, that squirrel is nuts about Daisy leaves.

Monday, October 14, 2013

Ole Bumpy-wings... A Meadow Katydid

   On a recent Sunday stroll in western Pennsylvania, we heard the 'tic-tic-tic-buzzzzzzzzz' of some meadow katydids calling in broad daylight from the tall grasses along the edge of a wetland area.  Their calling-song caught our attention since we don't seem to have this particular meadow katydid in our home area.  We searched awhile to locate these singing katydids.  When we did, we found this green, grasshopper-like insect with bumpy wings and a peach-colored head - the Black-legged Meadow Katydid (Orchelimum nigripes).
Black-legged Meadow Katydid - Orchelimum nigripes
    We soon discovered the reason these katydids were hard to find... they managed to hide by deftly spinning around to the backside of their perches as we approached.  My sharp-eyed son eventually spotted one in a bush.... and by fooling the katydid into thinking another intruder was approaching from a different direction, it rotated around into position for me to take photos.  I even took a video of this intriguing insect.
   Here is a video of a Black-legged Meadow Katydid (Orchelimum nigripes) as it sings from a bush near the margins of a wetland.  This is the calling-song I described as 'tic-tic-tic-buzzzzzzzzz'.
video
   Notice how the left tegmen (fore-wing) overlaps the right one in front of those unusual peaks in the middle of the fore-wings.  The calling-song is produced from vibrations of the fore-wings when the row of teeth on the one tegmen is swept across a 'scraper' on the other tegmen.
   You all know I think there's more to enjoying nature than simply identifying a newly encountered something. Therefore, when I encountered the Black-legged Meadow Katydid, my mind began to whirl... for I saw the unusual-looking peaked wing-covers (tegmina) of the meadow katydid males....
Black-legged Meadow Katydid - Orchelimum nigripes
 ... Why are they designed with that unusual shape?   Are those 'peaks' specialized structures that are part of the katydid's sound-producing mechanism?  Do those 'humps' function as part of a resonance chamber?   Etc.
Black-legged Meadow Katydid - Orchelimum nigripes
    Those are curious-looking wings, eh?  At least they sure have made me curious.  I reckon I will go searching for other members of the the meadow katydids (Orchelimum) which might be singing near the 'swamp' just up the road from home.  I wouldn't mind taking a closer look at those fore-wings.

   All that, and more... from hearing a  'tic-tic-tic-buzzzzzzzz' emanating from the tall grass beside a swamp.

Thursday, October 10, 2013

A Little Scientific Discovery

Could something new to science be found in your backyard... or mine?
Perhaps I may have made such a discovery - a very small one - as I drove along a woods road not far from home.
coltsfoot patch along the road
As I drove along (looking for a property corner pin), I spotted some leaf mines on Coltsfoot leaves.  I stopped to take a look and thought to myself, "Those larvae make such long, torturous leaf mines... I wonder what mines those leaves?"
roadside coltsfoot patch
  "Wouldn't it be fun to see what makes those twisting tunnels on the coltsfoot leaves?"
leaf mines of Phyllocnistis insignis on coltsfoot leaf
Well, in hopes of rearing an adult from the leaf mines, I picked a couple leaves and put each leaf in its own container.  A few days later I noticed there were several tiny, shiny micromoths zipping around in their rearing containers.  These moths were a shiny metallic color that, in the right light, are a subtle blue-grey.  The moths have orange racing-stripes decorating their wings as you can see in the photo below.  Here is a photo of the flashy little moth,  Phyllocnistis insignis.
Phyllocnistis insignis - reared from coltsfoot leaf mineAgain, these are very small moths.  P. insignis would be dwarfed by a grain of rice.

 I puzzled over these coltsfoot dwellers for awhile and couldn't find answers, so emailed an expert and here is a portion of his reply. 
"... There is, however, no published record of this moth mining in coltsfoot, and you may well be the first person to have reared it from this plant.  I have been seeing these mines for some time, and had assumed they must be P. insignis, but it's great to have this confirmation."
   Ahhh, so my coltsfoot dwellers are well known, just not documented in association with the plant from which I reared them.  Therefore, I'll publish this little discovery here in hopes that it counts as a 'published record' and adds a tiny bit of info to the body of scientific knowledge.
   First, here is a photo of a leafmine typical of the many I have found on coltsfoot leaves (Tussilago farfara).  The twisting tunnel of the P. insignis larva is on the upper surface of the leaf.
long, twisting leaf mine of Phyllocnistis insignis on coltsfoot leaf

   Here is a photo of a leaf miner larva, P. insignis, as it feeds on a coltsfoot leaf.   The mines are exceptionally long because these particular leaf miners feed solely on sap from the damaged leaf tissue.
larva of Phyllocnistis insignis mining coltsfoot (Tussilago farfara)

   When the leaf mining larvae are finished feeding and are ready to pupate, they make a kind of three-sided chamber right there on the leaf surface at the end of their feeding tunnels.
pupal chamber of Phyllocnistis insignis on coltsfoot leaf

  The pupal chamber on the coltsfoot leaf pictured below, is very near where the leaf miner started mining the leaf.  See the thin trace of the early mine on the lower left of the pupating leaf miner?
leaf mine and pupal chamber of Phyllocnistis insignis on coltsfoot leaf
Here is a close-up photo of a silken pupal chamber.
pupal chamber of Phyllocnistis insignis on coltsfoot leaf
The photo below shows a pupal chamber with a spent pupal case protruding out the end.
spent pupal case of Phyllocnistis insignis on coltsfoot
The photo below shows the freshly emerged moth.
Phyllocnistis insignis reared from leaf mine on coltfoot
Most of the life story of this flashy little moth is shown in the photo below.
long, twisting leaf mine on coltsfoot leaf
A story that starts out as a thin squiggly line and ends in a pupal chamber after traveling over various parts of a leafy world.
Here is another 'volume' written by P. insignis.
squiggly tunnels on coltsfoot leaf
Amazing isn't it?  A resume... a life story... written on a leaf.  A leaf story, which in my 'backyard', was written a on coltsfoot leaf... and may have gone undocumented until now.

Tuesday, October 1, 2013

Discovery In A Coltsfoot Patch

Could a patch of coltsfoot along a woods-road be a good spot for a new discovery ?
Coltsfoot along a woods-road
Yes, even though coltsfoot patches are quite common (at least around here), it seems I may have documented something 'new'.  Now, it's nothing big like a new species... but click here to see what I found in the coltsfoot patch  (next post).

Thursday, September 26, 2013

Violet Seed's Ballistic Seed Dispersal

Violets have a ballistic seed dispersal system that I enjoy seeing in action.
   Whenever I see a that violet seed capsule has just opened, I pause to watch as it launches its volley of seeds. This particular time I was able to grab my camera and take some photos and video as I watched the violet's explosive seed dispersal event.
   Here is a photo of the violet's recently opened seed pod.
Violet seed dispersal

Here is a video of violet seed being dispersed... a video of violet's ballistic seed dispersal in action.  Watch as one seed pops out on the right... then another from the left.
video
This video of the violet seed dispersal was cut to include just two seeds being shot...  Also, I slowed down the speed a bit.
Here is another video of the violet seed dispersal event.  The video shows a violet seed being fired, and if you listen, you can hear the seed hit the camera.
video

Here is a series of photos showing violet seed dispersal.
The seed dispersal began soon after the fully-developed seed pod was raised up where where it could dry out in the sun.
unopened violet seed capsule

 As the violet seed capsule started to dry out, it split open into three boat-shaped sections that revealed the seeds and pointed them toward the sky... ready for launch.
violet seeds ready to be launched
Then, as the seed capsule continued to dry, the seeds were squeezed from both sides of their boat-shaped launch pad until they started popping out.
violet seed dispersion

After a few minutes of shooting seeds, the seed pod looked like this...
Here is another photo showing the violet seeds part-way through the dispersal event.

 Here is a photo showing a violet's seed capsule after all the seeds have been shot onto the surrounding landscape.
empty violet seed capsule

   Now, the story is not over, because after the violet seeds were scattered to a reasonable distance by that ballistic dispersal system, another seed dispersal mechanism is ready to take over.  The violet seed are further dispersed and planted by ants...
   Here is a photo of one of the violet seeds.  See the white elaiosome on the left side of the seed?  That is ant bait... designed to lure ants into dragging the seed off to their nest.  There the elaiosome will be eaten and the seed discarded - well, for the seed that's transporting it to new location and also the convenience of being planted.
violet seed waiting to be dispersed by ants
   I don't have a good photo of mymecochory (seed dispersal by ants) in action. Chasing a scurrying ant with a macro lens isn't exactly easy, although I can't say I didn't try...  I'll have to wait to post on that until another time I encounter ants transporting the violet seeds (when I have my camera) and, more importantly, if my photos turn out to be acceptable.
   It's likely this happens in your backyard as well.  I hope you have had the privilege of witnessing violet's seed dispersal methods while it happens.