Tuesday, July 31, 2012

Leaf Cutter Bees And Neat Round Holes In Rose Leaves

 I always marvel at the neat, round holes in the rose leaves... precision cut by leafcutter bees.
   The small leafcutter bee removes these leaf cut-outs, leaving holes neat enough to look almost like they were made with a hole-punch or a cookie cutter.  The bees roll up the leaf pieces, fly them to their nests.... which are (preexisting) tunnels in wood, or in the ground. The leaf circlets are used to line the bee's nest cells.
I've never had the good fortune of having a camera in hand when the leafcutter bees were doing their leaf shearing, so all I have to illustrate the leaf cutter's fantastic actions is a picture after the fact.
Here is a photo of a leafcutter bee gathering nectar and pollen from a thistle flower-head.
   The bee in the picture above is not necessarily the kind of bee which cut the holes in the rose leaves (top picture).  But, it is one of the many species of bees which are leaf cutters.
   At the bottom of the picture below, there is a leafcutter bee nest which was removed intact from a hole in a barn board. Notice the various leaf pieces which are fashioned into the cylindrical nest-lining.  One of my children placed their finger in the photo for scale.

   The other object in the picture above, is a cross-section of the leafcutter bee's nest material which shows part of a leaf-liner containing the mixture of pollen and nectar she places inside her leaf-lined tunnel.  The white "grub" is a leafcutter bee larva which had been feeding on that yellow/orange pasty mass of pollen.
Leafcutter bees are smaller than honey bees.  Their heads seem to be extra large for the rest of their bodies.
Leaf cutter bees gather pollen on the pollen brush on the underside of their abdomens, rather than in pollen baskets on their legs like some other species of bees.
The leaf cutter bee in the photo below has pollen from Vetch flowers collected on its pollen brush
I like to watch the leafcutter bees on thistle flowers... they seem to "swim" among the florets.
They also hold their abdomens in an unusual position
I suspect the reason for her comical position is... she doesn't want to accidentally brush off any of that precious purple pollen.
    Presently, a leafcutter bee is making a nest in a small hole in the edge of a piece of plywood shelf in my shop.  The bee is rather elusive, so I haven't snapped any pictures of it...  it is so quick at approaching and disappearing down its hole as it brings supplies to its nest.  Oh well, at least we can envision what its doing in there, as well as picture its signature leaf-holes somewhere out in the fencerow.
   If we would have some solitary bee nesting tubes mounted in a bee house in our backyard, I reckon it would be easier to observe and photograph these interesting bees.

Wednesday, July 25, 2012

Something's in the air! Part II

Something is calling these little yellow ants out of their underground nest.
What signals are these ants detecting?  It sure looks like they hear, smell, or feel something... something big!
    What a sight to see... these swarms of ants clustered around their holes, all facing outwards with antennae waving... it really looks as if a war is going to break out.
Charge!
No, it's not a battle formation, but rather, an assemblage in preparation for the "flight of the queens".  These pictures show the beginning of a mating flight of a Citronella Ant colony.  This is when crowds of queens and males leave the ant nest and fly away to start new colonies.
    From the appearance of the ants, I can't decide if they are waiting for a signal... something blowing in the wind, or, are they are so used to their dark, underground habitat that they are very timidly approaching the bright world above ground.
  As I mentioned in my previous post, these citronella ants are subterranean farmers... farming aphids and mealybugs down there in their hidden world.  Here is a photo of a tiny yellow ant sipping a droplet of honeydew from one of its "cows".
 I suspect the citronella ants left their "cows" out to pasture during this momentous occasion. 
  Whatever triggers the swarming of these yellow ants, it's a yearly thing for them to send off their winged ants to start other new ant colonies.
  The first noticeable part of their nupital flights are the cavernous holes (at the scale of these tiny ants) into the ant nests that show up in the yard.  I presume these are probably excavated for the occasion of this yearly sending-out party.
I've noticed these holes, with their attendant ant horde, in the afternoons and early evenings.  The little yellow ant workers gather around the entrance like guards with the winged ants waiting in the wing... waiting for something.
   Soon, with seemingly much trepidation, the winged ants start to emerge from the nest.  The ant queens don't leave right away... some just show up and play the waiting game with the workers. 
   Notice that some kind of communication is happening among all those ants.
Each ant must know what part it plays in this huge undertaking, but I haven't totally figured out what their individual jobs are...  except maybe the ant on the pebble in the foreground (below).  It was playing "king of the mountain" for a while. 
   During this waiting stage of the "flight of the queens" there seems to be alot of kissing up, along with much grooming.  Then, there are all the farewells.  Perhaps there are encouraging words like, "You go girl!" and, "Go for it!".  At least, that's what I get from the picture below.  Oh, of course there are the pre-flight checks.
   Eventually the signal they were waiting for arrived... I didn't hear it or smell it.  Towards evening, at some signal (or mob mood) they pour forth....
 and the flight of the queens (and males) begins!
 The place is all a frenzied flutter.
Patches of ground are busy with activity. The air is littered with the new flyers... the young ants with wings, and also filled with the smell of citronella.  The citronella smell could be from ants I inadvertently stepped on.
Yes, something's in the air: flying ants and their signals.

    Incidentally, these boys aren't sluggards, but there is still wisdom to be had by considering the ways of the ant.  In the context of this event, I suppose one thing they could learn is... that there is a right time to leave home and start a new one (I might add "Hopefully, not far away").
  BTW, this "flight of the queens" took place in the same sand volleyball court where I took some pictures of ground-nesting solitary wasps with their nests and prey.

Saturday, July 21, 2012

Something's in the air!


   Something is calling these Citronella Ants out of their subterranean home.  They have left their aphid farms down below, and with much foreboding (at least that's what it looked like to me, and I saw it all happen from mere inches away) are leaving their underground dwelling and entering the bright world of a summer afternoon.
See my next post about these Citronella Ants to learn what happened.

Friday, July 20, 2012

An American Crow Using A Tool

   I have a new fascination with crows because of what happened in our backyard.  I saw a crow use a tool to retrieve some food.  I've heard of crows making and using tools, but I never really thought I'd get to observe that phenomenon... right from my desk chair.
   I watched the crow's impressive feat while I was sitting at my desk.  I glanced out the window and saw a crow trying to pull a hard pretzel (old, stale ones) out of a plastic bag.  What caught my eye was the antics of the crow as it tried to pull a whole pretzel out through hole in the plastic bag... it was bouncing up and down, jerking on the pretzel... but to no avail.  Then, the crow let go of the stubborn pretzel, and of all things, picked up (in its beak) a piece of broken pretzel that was shaped like a hook... and used it as a tool!  The crow hooked the pretzel-tool into the plastic bag and tore the hole bigger!  Before I even had time to think about snapping a photo, the crow dropped the hook-shaped pretzel, pulled out the whole pretzel through the enlarged hole, and flew away.  I reckon crows are smart birds.
    Here is a link to a video of a crow fashioning a tool and using it to retrieve some out-of-reach food.
   Our backyard tool-wielding crow had some companions.  They are regulars around here.  I'm thinking of ways to set up a camera to photograph them using tools.  I would love to snap some pictures of a tool-wielding American crow (hopefully without taking pictures through two window screens and a glass window). Hmmm... maybe a trail cam  facing a tall, clear container with some pretzels at the bottom... and a handy piece of wire nearby.
  Somehow, crows don't seem so boring anymore.

Tuesday, July 17, 2012

From Bird Poop To A Butterfly

   When I first saw this caterpillar I thought, "Wow, that caterpillar looks like bird poop".
    Not only was the caterpillar camouflaged to mimic a bird dropping (with a disgusting-looking smear of white and green), but it had this strange habit of hanging its head down below the branch... as if... part of the "bird dropping" was about to drip off the branch.  It didn't immediately cross my mind that the ugly caterpillar would soon turn into a beautiful butterfly.
   Later, I took notice of all those spikes on the caterpillar's head as well as those odd bumps all over its body.  Simply ugly. This is the caterpillar of the White Admiral butterfly... and there is no similarity between the two.
    Needless to say, I decided to keep watch over the caterpillar. It's not everyday that I run into a caterpillar disguised as bird droppings... plus, it was right at eye level on a branch of a young aspen in our backyard.
   The caterpillar's bird-dropping disguise wasn't its only defense.  It also had a rather unusual defensive posture.  When I poked the caterpillar it drew itself into the position pictured below.  Perhaps this position is somehow part of its disguise. Or maybe it makes the caterpillar look dangerous or more unappetizing.
  The caterpillar seemed to rest in a similar position.  I often saw the caterpillar in the position pictured below... unless it was eating aspen leaves.  Maybe this pose is just a safe way for it to rest (spiked horns lowered and ready to swing an an approaching enemy).
See what happened when an ant came along...



 The ant fled.  I reckon it fled all those spikes and bristles.
   If I were the size of an ant... facing that caterpillar's menacing face would be like coming face to face with an angry moose.
   Since the caterpillar was so unusual, and also so conveniently located, I covered the aspen branch with mesh to protect the caterpillar from any sharp-eyed birds or parasitic wasps.  The thought was to keep it safe (and confined) until it turned into a butterfly.  Shortly thereafter the ugly caterpillar pupated. 
In other words, that ugly, disgusting, bird-dropping mimic caterpillar turned into this odd-shaped chrysalis. 
   One week later, the metamorphosis was complete... when a beautiful White Admiral butterfly emerged from that strange-looking chrysalis.  Lovely butterfly, isn't it?
The White Admiral, Limentis arthemis, is a medium-sized butterfly that I would describe as a black and white butterfly with orange and blue spots.  The White Admiral butterfly is one of the brush-footed butterflies... see how it acts like it only has four legs?
  I snapped a photo of the upper side of butterfly's wings seconds before it flew away.  The photo shows the circling band of white spots, or bars, against the black wings that are highlighted with iridescent blue.
   I'm slightly disappointed I didn't get to witness the whole life-cycle of this butterfly.  Somehow I  missed spotting the butterfly egg and even the caterpillar when it was young.  However, I (we) did get to see that  bird-poop-looking blob of a caterpillar turn into a beautiful butterfly... now that's complete metamorphosis on display!

Saturday, July 14, 2012

Pip Galls = Pandemonium in the Pin Oak

Recently there has been a small uproar in the Pin Oak over some honeydew-exuding pip galls.
   The yellow-jackets and ants have been all in a frenzy over the glistening globules of honeydew oozing from the tiny galls.  I'm pleased to have this drama playing out in our backyard.  As you can tell, I too, am going to make a fuss over these oak galls, because what is happening within (and without) those galls is profound!
   In my opinion, the picture of the honeydew droplets on the acorn pip gall (above) represents one of the most amazing things I've posted about so far in all 200 of my Nature Posts.
   Think about it... a wasp larva hidden inside this small gall has caused the oak tree to grow the gall to feed and shelter the larva.  Not only that, but the gall-maker also causes the gall to ooze honeydew which attracts yellowjackets and ants.  These in turn, protect the gall as a food source, and in doing so, are unwittingly protecting the gall's inhabitant from parasitic insects.
 The fact that these wasp larvae can cause their oak galls to ooze honeydew is, I think, the most incredible thing about these pip galls.

Now, it is amazing how the Cynipid gall wasp larva causes its host plant to grow a structure that houses it and also feeds it,

but, hey, gall-makers do that kind of stuff all the time.

   What this larva is programed to do is bordering on awesome.... the wasp larva can cause its host oak tree to turn the larva's larder/shelter into something like the nectary of a flower whose job is attracting guards (protectors) instead of pollinators.  Profound!

 Check out the photo below and you'll see what I mean.  Who would argue with this guy... when you can see it claims the gall... and says, "It's mine.. all mine... and if you stick that big thing any closer... I'll..."
Ants slip in for a sip of the honeydew when they get a chance.
Ants are protective of their honeydew sources as well.  I didn't try this with the ants on the pip galls, but with ants milking honeydew from aphids, a finger placed nearby will soon be covered with agitated, biting ants.
 Our Pin oak was bustling with prowling yellowjackets and scurrying ants hunting for the honeydew droplets.
  Pin Oak's lower branches characteristically droop, so as I walked past, these amazing galls were right at eye level and easy to observe.  Finding information on the galls wasn't quite as easy.  I found little written about these acorn galls.
I did find, on page 100 of Lewis Hart Weld's Cynipid Galls Of Eastern United States, a brief description of the acorn pip gall of Callirhytis balanacea.  These galls seem to be a match....
They are small, round, green galls which grow on the stems beside (or out of) the young acorns.  They secrete honeydew.  They drop off the Pin Oak tree in late June.
   Over the time I was taking the photos of the galls and the honeydew seekers, I noticed that the galls were disappearing.  Since the pip galls drop off when they mature... and because I wanted to confirm in my mind that there were many more galls up higher in the Pin Oak tree... I laid a small tarp under a portion of the Pin Oak in order to catch the dropped galls.
About a dozen of the detached galls landed on the tarp over the period of two or three days.  Then the galls quit dropping.  The dropped galls quickly turned black.  I guess the pip party's over for this year.

   Ahhh, if only honeydew galls were really big (I'm thinking big enough for a good human-sized sip of honeydew) and there were always lots of them!  Well, a moderate amount of them... we need acorns as well.

Maybe I just wish... that there would always be some pip galls in the pin oak.

BTW... I doubt many people purposefully search the web for acorn pip galls.  Perhaps you, my regular readers, would pass this post along (via email, etc) to some folks you know who would enjoy these pictures of yellowjacket-protected pip galls.  Wouldn't it be great to perpetrate some online pandemonium over pip galls in the pin oak?