Monday, 22 June 2009

Macro Monday

Lantana camera

This is a close up of a flower bud of the alien-invasive, Lantana camara in my garden. The flowers of this plant attract a lot of butterflies.

Macro Monday HQ is at Lisa's Chaos.

Thursday, 4 June 2009

Dawn of a Dropwing

The front covers of the only two books dedicated to the dragonflies and damselflies of Sri Lanka has one thing in common. They both feature a widespread Oriental dragonfly Dawn Droping Trithemis aurora. Sri Lanka is home to 117 species of dragonflies and damselflies out of which a whopping 53 54 are endemic. Some of these endemics too are strikingly coloured. How then can you explain this species of dragonfly being chosen to adorn the front covers of the said books? They say not to judge a book from its cover. But, on this, it is hard not to.


I am happy to announce that my dragonfly pond has produced the desired results—attracting more dragonflies, getting them to breed in the pond, and photographing them.

Of the numerous dragonflies that have shown interest at my pond, the Dawn Dropwing has shown a remarkable breeding success during April and May. Its emergence, as most other dragonflies, happen at night, in the cover of darkness—typically at around 8.00 p.m—when I do not like anything to come between me and prime time news.

Dragonflies and Damselflies lay their eggs in fresh water where their larva (aka. nymph/naid) grow. To transform into a dragonfly, the nymph should to leave the aquatic world, and attach itself to a leaf, rock or twig near the water. In my pond, the cradle often takes the form of the outer wall of the raised rectangular rim.

This is how the nymph of Dawn Dropwing looks like when it has surfaced out to the open.

Dawn Dropwing Nymph
Would it ever make to a front cover of a popular natural history book on dragonflies?
Sorry, I am being mean.

Most of these photographs were taken in April, which is the hottest month here. Even working at night made no difference as it was very humid. This was made worse by the mosquitoes, which forced me to be fully clothed in outdoor wear to prevent them from causing havoc. From the moment the dragonfly nymph surfaces out of the water to the time it ends its metamorphosis as a teneral or a young dragonfly can take several hours. So I can tell you that these pictures were obtained in pretty sweaty circumstances.

Anyway, this is how it looks when the teneral dragonfly begins to emerge breaking the larval skin during the early stages of its final metamorphosis.

Dawn Dropwing emerging
The sand particles sticking on the nymph's moist body give it a good camouflague by disguising its real profile against potential predators. But, the ghostly teneral that emerges is pale in comparison, and could be easily spotted by predators. This is a critical stage of its metamorphosis. As the helpless teneral emerge, it becomes easy prey for predators lurking near the water. Look how the ants gang up against one sorry teneral Dawn Dropwing—which never saw the light of the dawn. (Kim, it was too late when I found this!)

Dawn Dropwing emerging
Post-mortem: the ants have punctured a hole the young dragonfly's body in the thorax as its blood (hemolymph) was being pumped during the process of metamorphosis. This drained vital supplies needed for its body to expand and halted the process of growth. Click on the image below to view a large image to see a drop of its blood in the back of its thorax.

Dawn Dropwing
Eventually, the ants succeeded in inflicting a slow death on the teneral through this fatal bite. They marched away with their prized catch soon after.

Coming back to regular cases of metamorphosis, as the nymph works its way out of the exoskeleton the end of the abdomen remains inside the exoskeleton. The dragonfly then flips itself upward by a move that is similar to an upside down sit-up. It then grabs onto the lifeless exoskeleton, and pulls out the remainder of its abdomen. After a while it looks like this.

Dawn Dropwing emerging
The wings, when the dragonfly first emerges, are shriveled and opaque. The wings are pumped full of fluid to expand them, and when fully expanded, they harden and finally become transparent.

Dawn Dropwing emerging
Here's a different angle of the above.

Dawn Dropwing emerging
The young male Dawn Dropwing obelisking below looks similar to the female in colours. It takes several days before it assumes the guady colours of the adult males as in the very first picture.

Dawn Dropwing juvenile male

By the way, this water lily species (?a hybrid of Nymphaea nouchali) is doing very well in my pond. Here's a close up of its anthers.

Blue Water-lily
I conclude this post with an abstract of a male Dawn Dropwing that I photographed sometime ago. It doesn't show its real life colour though, which is why it is an abstract! I am looking forward for more captures of the adult showing its real life colours. The one shown at the very top was taken way back in the ancient history using a Nikon Coolpix 4500—my first digital camera that I got for digiscoping birds.

Dawn Dropwing

Monday, 1 June 2009

Related Posts with Thumbnails