Flower Spider on White Donkey Orchid

Flower Spider on White Donkey Orchid
Diaea evanida on Diuris punctata (alba)

A Member of the Nature Blog Network

Nature Blog Network

PHOTO SIZES REDUCED FOR QUICKER DOWNLOAD

HAVING SEEN THAT MY BLOG IS SLOW TO DOWNLOAD ON A FRIEND'S COMPUTER,
EVEN THOUGH HE IS ON BROADBAND,
I HAVE DECIDED TO UPLOAD MY IMAGES AT MUCH LOWER COMPRESSION THAN PREVIOUSLY.
THE IMAGE SIZES WILL STILL BE STANDARD IMAGE SIZES.
1000 PIXELS WIDE, OR 600 PIXELS FOR SMALLER IMAGES.
THE FILE SIZES WILL BE ABOUT 100 Kb.

HOPEFULLY THIS WILL ALLOW MUCH FASTER DOWNLOAD SPEEDS.
BUT WITH REASONABLE QUALITY.

Comment Moderation Upgraded

In view of a recent outbreak of Spamming,
I have been forced to add in "character recognition" (verification) software,
to minimise the chance of computer generated spam messages.

.
I apologise to real people reading my blog if it makes it harder for you to comment.
I find if I close one eye and squint at the funny letters,
that usually makes it easier to read the mysterious jumbled letters.
You need to copy them into the space provided in the "Comments" form.
I RESERVE THE RIGHT TO CONTINUE TO EXPLORE ISSUES OF PUBLIC ACCOUNTABILITY.

Wednesday, May 13, 2009

Stonefly larvae in pools on the sandstone.

Here is a tiny pond creature I found in a pool of water beside a track, out on a sandstone plateau. It was only about 0,5cm long (5mm). It is equipped with a formidable set of jaws, and its other most noticeable feature is the prominent paired cerci (tail appendages). I knew enough to know that Mayflies have distinctive triple cerci. So what was this? Obviously not a Mayfly larva.

Here is one of these tiny creatures photographed from the underside.
Another image of the same specimen. Unfortunately, some pool debris is attached to the tail, confusing me as to its proper shape. Fortunately the dual tail antennae are clearly visible in the first shot.

"Stoneflies, order Plecoptera, are distinguished by two long thin tails projecting from the rear of the abdomen. The body is somewhat flattened, and there are two claws that extend from the three pairs of segmented legs. Stoneflies are considered crawlers and crawl around looking for food. They are not tolerant of water pollution."
Links courtesy of the St John's Water Management District, Florida USA.

After some time studying this pool, it was obvious that there are other far smaller creatures moving around in there, which I would need a laboratory magnifying lens or microscope to study. Stonefly larvae are classed as "crawlers" by people who study pond life.What surprises me about finding many of these tiny larva is that I have only once identified an adult Stonefly.
It was a moderately large flying insect (as large as an average Dragonfly). This one was found beside the Wingecarribee Swamp in November 2007. But here were lots of Stonefly larvae out on the sandstone plateau, but I have never seen adult Stoneflies there. A puzzle to me.

3 comments:

Tyto Tony said...

Do they try to avoid danger by making transition from pond to foliage at night, perhaps after drying new wings in late afternoon?

Denis Wilson said...

Hi Tony
Good question. I wish I knew.
Obviously these guys are very young, or else a different, far smaller species than the one I have seen as an adult.
Cheers
Denis

Mingfei said...

Interesting insects!

SiteMeter