Sunday 17 October 2010

Holding Your Breath

 

The current Southwest monsoon season can be a bit of a damper for dragonfly excursions.  Sometimes. 

Some days start out nice and sunny in the morning but the weather suddenly changes.  It then starts raining and the sky is overcast for most of the day after that.  Sometimes, the weather would be really nice but I would be tied up with work and other stuff instead.

Also, I have to admit to being a bit lazy sometimes, not wanting to do anything at all, even on a day when it is really nice but maybe a bit too hot as I have already been out in the sun quite enough during the week.

Ahhh... humans!  We are such complaining souls!  Without the sun and the rain, we would not have this beautiful, big blue marble!

Anyway, I have been wanting to share with you an observation about the ovipositing behaviour of these damselflies but for some reason, I have been putting it off till now.  These damselflies are of the Pseudagrion spp, Pseudagrion australasiae if I am correct.

There was this one afternoon a few months ago when I was at this pond filled with murky-looking stagnant water.  Yet, it was buzzing with activities. 

It's like there's been a mass wedding! 

There were lots of dragonflies and damselflies flying around.  A few were in tandem and in wheel, and even more were ovipositing in the pond.

With the P. australasiae, the male is in tandem or contact guarding while the female oviposits.  The reason for this behaviour is to ensure that the female can complete laying the eggs that have been fertilized with his sperm. 

In most species of dragonflies and damselfies, both the males and females may mate repeatedly.  Therefore, due to sperm competition, the males maintain tandem contact to prevent other males from displacing their sperm from the female damselfly before ovipositing is complete.  Contact guarding during oviposition also increases the probability of the female laying a complete clutch of eggs.

Sometimes, other male damselflies may attempt to disengage a pair in tandem to disrupt the copulation or oviposition process, clamoring to be her next suitor.

What do you think the male damselfly would do?

 

Here's a pair of damselfly with the male in tandem guarding during oviposition.

 

There was another male damselfly hovering around, so the female was pushed deeper into the pond.

 

And they kept going deeper till the female is now completely submerged.

 

As the place was still buzzing, they kept descending.

 

Until the male is also submerged and the female can now oviposit in peace.

 

This must be a favourite spot for these damselflies... another pair of damselflies started ovipositing here as well.

 

That female damselfly was submerged for quite a few minutes.  Most people can't even hold their breath underwater for that long!

Fascinating creatures!

 

 

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