Newly emerged male Orthetrum sabina sabina (Drury, 1770) on 25 January 2007

 杜松蜻蜓/狭腹灰蜻

Shortly after emerged from his  exuvia.

Dragonflies usually emerge at night to avoid predation during this vulnerable time.  Some species wait for sunrise. This larva I collected a few days ago has completed its growth  Every evening it will stay at the water surface with out moving.  I knew he is waiting for right circumstances to  leave its aquatic environment and start a new life. For 3 nights I kept on guide and check on him  every 2 hours but he did not emerge.  Only on the 4th night he choose a moment when I was completely not around.

Some species of odonates can emerge on a flat surface (Gomphidae for example and most damselflies). But this need a vertical grass or reed  stem to climbs up  until it is well out of the water, and affixes itself firmly by means of its claws.

After a pause, the larval skeleton  breaks at the back of the head and laboriously, the adult dragonflies emerges. Emerged first the head, then the thorax, then the legs, and then the wings. Soon the newly emerged dragonfly is able to fly. The process takes about two hours.

'Blood' is then pumped strenuously round the body to  expands the body and wing, transforming them into a full beautiful flying insect.

Most dragonflies after emerging immediately head away from water and fly off into the surrounding green bushes to hide for a dispersal period of  few days to few weeks to go through a period of maturation of about one month During this  period  the newly emerged insects attain  sexual maturity and the body color brightens.  This male Orthetrum sabina sabina already has 90% of his color and patterns developed as soon as he emerged.

After they matured they will then make their way to back to the water where they came from to mate.

So for this little male,  instead of freeing him  to the drain. I release him to a garden 100 meters from the drain.  This backyard has a patch of tall green plants where other species of dragonflies also came here for the dispersal period.

 
25-1-2007 10:36 PM
1 hour after emerged		 26-1-2007 9:47 AM
11 hours after emerged

The wings are still in upright folding position and tenderly soft

The face, as can be seen from above image, is still flat.

The wings are spread out to both direction and are elastic by now.

The face is round and extended out now.
Dragonflies can't fold their wings, but  baby dragonflies fold their wings at birth.

The images at left shown this male Orthetrum sabina has his 2 wings folded in upright position for a bout 2 hours after emerged.

Exuvia of above male Orthetrum sabina sabina (Drury, 1770)

This is the exuvia left over by above male Orthetrum sabina

The size of the exuvia is 2cm in length and 1 cm width at abdomen
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Click here for detail images of Exuvia of Orthetrum sabina sabina (Drury, 1770)

 

Photo on 20 Jan 2007 morning, location of the the larva of this male Orthetrum sabina. (5 days before emerged).  From the picture can see the drain was very shallow with only 2 to 3 inches of water without rain for the past several days. The upper part of the drain was already dried up with a small patch of water trapped with hundred of tadpole and this larva.  

The emerged male Orthetrum sabina was released here on 26 Jan 2007 morning. A small bush of plants 100 meters from the above drain.  This back yard has been a sanctuary for several species of dragonflies. Young emerged dragonflies found the way here to hide and feed during their period of maturity.

9:51 AM. The next moment, he flew up above  into the air.