Cool Dragonflies

 

Normally dragonflies perch with their tails lying perpendicular to the ground as seen on the left.  The dragonfly on the right has its tail pointing straight up.  Why?  This is one of the ways that dragonflies stay cool, especially during our hot Southeast Texas summers.  With its tail pointing upward it reduces the amount of surface area exposed to the sun thereby reducing body temperature.

Dragonfly Down

 

While the wife and I were relaxing outside on the patio, this male green darner came crashing to the ground in front of us.  The first thing that was obvious about it was its missing tail or what is really known as the abdomen.  (Note that a portion of the abdomen left behind is violet in color- this indicates a juvenile male.)  I'm pretty sure I know what happened.  As I have stated before I have a purple martin colony and these birds love dragonflies (as do many other birds) and there was a few martins flying above us.   I'm thinking that possibly one of my martins had this dragonfly in its beak and it wriggled trying to free itself, which then severed its abdomen and sent it to the ground.

Asp

Known around these parts of Southeast Texas as an “asp”, the caterpillar of the Southern flannel moth (Megalopyge opercularis) hides poisonous spines within the pelt of hairs that cover it.  Labeled as the most venomous caterpillar in the US, this harmless looking caterpillar has a sting from that packs a wallop, which I have experienced personally. If I were to try and describe its severity- it's akin to placing the business end of a lit cigarette against your skin.  I’ve read that a good way to ease the pain is to remove any spines that were left behind in your skin with a piece of cellophane tape.

Kinsey's Wasps

Check this new episode of Shelf Life from the American Museum of Natural History on Alfred Kinsey's gall wasp collection.

Searching For Nature Treasures

"Most children have a bug period, and I never outgrew mine.  Hands-on experience at the critical time, not systematic knowledge, is what counts in the making of a naturalist.  Better to be an untutored savage for a while, not to know the names or anatomical detail.  Better to spend long stretches of time just searching and dreaming."       E.O. Wilson

"The most effective way to connect our children with nature is to connect ourselves with nature.  If mothers, fathers, grandparents, or guardians already spend time outdoors, they can spend more; they can become birders, anglers, hikers, or gardeners.  If children sense genuine adult enthusiasm, they'll want to emulate that interest..."      Richard Louv

The circular area around the base of the large oak in our vacant lot is covered in desiccated leaves- the same leaves that were created by this very tree.   This detritus is also a mish mash of small branches, acorns, bark, and the gnawed upon shells of peanuts from a nearby squirrel feeder.   This spot has gotten the undivided attention of my 7-year old grand-daughter.  She is on her hands and knees looking for something that most people would either not notice or would wonder why she is looking for them in the first place.  “Here’s another one paw paw!” she cries excitedly- an excitement that only a child or a nature-obsessed old man can savor. I take the crinkly remains from her and add it to the rising pile inside a large plastic peanut butter jar. “That’s number 25”, I reply, as if we’re trying to break some sort of record.

Cicadas (in this case the annual or "dog day" cicada) emerge from their chambers in the ground as nymphs, latching themselves to a tree or any other nearby object.  They then, over a course of several hours, emerge from their nymph exoskeleton, dry their wings out and then fly away to find a cicada of the opposite sex to mate with.  This exoskeleton is what she is looking for.   Just another treasure to add to her nature collection.

Seeing them amongst the leaf litter isn’t easy, especially for my old eyes.  It’s greatly due to their color which allows them to blend in quite nicely with the leafy surroundings.  For some odd reason their color and consistency remind me of fried pork skins.  yum..........

Mason Wasp

 Granddaughter told me of a mud wasp nest her Dad had found that was attached to their bbq pit.  We harvested it and began opening the cells to see what type of prey the adult had gathered and stored for its prodigy.  When we opened the first cell a fully developed mason wasp (Euodynerus apopkensis) began to crawl out.  It flew a short distance and landed nearby, and began twitching its thin, cellophane-like wings to and fro as if to stretch them following its long nap inside the lump of dirt, before flying away.

In another cell though we found another wasp that was not quite developed.  Its white form almost appeared ghost-like. 

We both felt a sense of guilt for disturbing it, so we decided to placed it back into its cell and then we collected some dirt, which we wetted and sealed the hole enclosing the pupa inside.  We then took the nest and placed it in one of her bug boxes. We’re hoping that it will continue to develop and then dig its way out, then we’ll release it.

I’ve seen this particular wasp in other areas, once in our firewood pile.  We had been rummaging around in the wood for geckos when we spotted one halfway into what appeared to be the exit hole of a wood-boring beetle. 

Not sure what it was looking for.  I later found out that these wasps will utilize or “repurpose” paper wasp nests.  Maybe it was repurposing the exit hole/tunnel of the beetle. 

Black and Yellow Mud Dauber Nest

I found this mud dauber nest underneath an awning that’s attached to my house and as you can see from the holes the wasps that had developed there ate their way out once they became adults.

I opened up the globbed mass and found the remnants of cocoons in the empty cells that had contained developing wasps.  This particular solitary wasp is a black and yellow mud-dauber which gets its name from its black and yellow coloration.  It, like most mud-daubers, hunts, paralyzes and stores spiders in the cells of their mud nests where upon an egg is laid and then the cell sealed.  Once the egg hatches the resulting larvae feeds on the spiders and eventually develops into an adult wasp.

Inside I also found two fully developed individuals who apparently were unable to free themselves and ultimately died where they were born.

Chrysalis vs. Chalcid Wasp

Back on August 17th my granddaughter and I were out in the front yard trying to get a photograph of a hummingbird that was feeding on some turk's caps.  All of a sudden I hear her cry out "paw paw look!"  I turn to see the chrysalis of a spicebush butterfly attached to a metal birdhouse we have hanging in one of our flower gardens under a camphor tree which, by the way, is one of this butterfly's  host plants.  I had been standing right next to it and  never noticed.  I'm constantly amazed how she has become adapted at observing things, most times before I do.

We decided to keep an eye on it day to day to see if we might be lucky enough to be around when the butterfly emerged.  That was to never be.  What I should have done was placed it in a jar protecting it from its natural enemies.

Today we found that it had a tiny hole in it.  And when I saw this I knew it meant trouble.  This is the workings of a chalcid wasp.  These tiny wasps lay eggs into the chrysalis during the time that it is formed when the tissue is soft.  The eggs hatch and the resulting larva consume the insides of the chrysalis and eventually develop into wasps which then bore a hole, as seen above, to escape.

Note in the first photo how the back end of the chrysalis is relatively straight.  In the second photo it is bent.   This is one of the signs of chalcid infestation.  Once the eggs of the wasp develops inside and begins to consume the developing butterfly within, the chrysalis dies and the muscles that once held it straight relax causing the bend to form. 

Check out this cool video showing how this wasp develops:


References and Suggested Reading:

1) Spicebush Butterfly Post
2) Chalcid Wasp Links  (a), (b)
3) Caterpillars of Eastern North America

Hackberry Emperor Butterfly Eggs

Granddaughter and I went to check on the turtle eggs we witnessed being laid back on July 2 near a hackberry tree, to see if they had begun to hatch.  So far there's no evidence that they have dug their way out just yet.  While we were looking we discovered a leaf on the hackberry tree that had seven tiny jewels upon its surface.  These were the eggs of the hackberry emperor butterfly.  This tree is the host plant for this particular species of butterfly.  When butterfly eggs are laid the female attaches them using a naturally produced glue-like substance to keep them in place.  The eggs are laid either singularly, in small clusters, or in a mass.

If you were able to look at these eggs under a microscope you would notice a spot known as a "micropyle", which is a "little door" where the spermatozoa of the male enter to fertilize the egg.  The micropyle also allows water and air to enter the egg as it develops.  Just like a chicken egg, there is yolk inside which nourishes the growing caterpillar.

As the caterpillar reaches maturity it frees itself by eating its way out of the egg and then feeds upon the host plant's leaves until its ready to transform by metamorphosis into a chrysalis or pupa and then eventually into a new butterfly.  What a nice find!