Monday, June 09, 2008

Heart-broken and happy about it

A few minutes ago, this pair formed a pretty heart.

Along the bottom of the White Rock bluffs, creeklets trickle into a ditch running along the railroad track and emptying onto the beach. There is never much water in it; the weeds grow almost to the bottom. In wider spots, pondweed and brooklime flourish. This Saturday, the damselflies were providing the sparkles.

I caught this couple in an odd pose.

Lined up, head to tip of tail, the one in the rear curving under ...

... and dipping her tail in the water.

What was going on?

I knew that damselflies mate in a "wheel", although it looks more like a heart to me. The male clasps the female behind the head, using claspers on the end of his long abdomen. She then curls around and under, bringing the tip of her abdomen to his genitalia at the bottom of his middle section. (There's a clear image here, in BugGuide.)

But this was no "wheel" or "heart". Were they confused? Oh, Google!

They're Western Red Damsels, Amphiagrion abbreviatum*, and they're laying eggs. The male retains his hold on the female's upper thorax while they search for a good home for the next generation. Then she dips the ovopositor at the tip of her abdomen into the water and deposits the eggs.

Why he holds her during this process is uncertain. He may just be making sure that no other male gets a chance at her until his contribution is dealt with. My Field Guide mentions that in some damselflies, the male actually lifts her from the water when she is finished laying. A rescue operation, as it were.

*These are the only BC damselflies where both the female and male are red.

1 comment:

  1. I weeta, thanks for this interesting info, makes me want to get into macro photos now...I learn a lot about BC from your posts too (and I live here!!!). Cheers.


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