Dragonfly Sex

One of the cool things about WordPress is that it tells you what people typed into a search engine to find your blog.  Somebody out there has been typing “dragonfly eggs” for the past couple of weeks and finding me…  but I’m sure they have been disappointed.  Up until now, I have had posts about dragonflies and posts about eggs… Now, finally, here’s a post about dragonfly eggs.

Ashy Clubtail - Male - by Jennifer SchlickAll dragonflies have 10 segments in their abdomen.  The one closest to the thorax is called segment 1.  Segment 2 on a male dragonfly is enlarged and contains sexual organs.  Segment 10 on the male also contains sexual organs.  Before finding a female, the male transfers sperm from segment 10 to segment 2.

Dusky Dancers - Tandem Pair - by Jeremy MartinOnce a male finds a female, he will use segment 10 to clasp a her behind the neck.  When you see two dragonflies or damselflies flying like this, it is said they are in tandem.

Next, the female will swing segment 10 of her abdomen up to the male’s segment 2 to retrieve the sperm.  At this point the pair is said to be copulating and may be described as a mating wheel.  On our dragonfly survey sheets, there are checkboxes for reproductive behavior.  Mating Wheel - Crimson-ringed Whiteface - by Jeremy MartinWe check “tandem” for any observances of tandem flight, “copulating” for any mating wheels, and “ovipositing” when we observe egg-laying.

There are a few possible ways that eggs will be deposited.  Some species will remain in tandem as the female oviposits.  Other species may separate, but the male stays nearby guarding the female from other males.  Still others simply go their merry ways…

Common Green Darners Ovipositing while in Tandem - by Kevin ArdinSome females deposit eggs by tapping their tails on the surface of the water, washing the eggs off, which then sink to the bottom of the pond.  Some land on vegetation and may even use specially designed ovipositors to pierce the surface of plant material so they can place their eggs inside.  If you want to see a wide variety of ovipositing methods, just go to Flickr.com and search everyone’s pictures for dragonflies ovipositing.  You’ll see all possible methods!

Finally, the eggs…  When I was at my very first Dragonfly Survey training in 2005, the Common Baskettails were putting on the whole show at the pond at Rheinstrom Hill.  We saw all manner of reproductive behavior.  What’s really cool about this species is that after ovipositing, their eggs expand into strings that resemble minature toad egg strings.  I was new to photography and only had my little Kodak Easyshare camera.  Still, I was able to capture this image of dragonfly eggs – for one species, at least:

Common Baskettail Eggs - by Jennifer Schlick

So, there you have it fellow web surfer: some dragonfly eggs. Enjoy!

Exuvia - by Jennifer SchlickI was pretty surprised when I first learned that dragonflies may spend as long as 7 years on the bottom of the pond as nymphs or naiads.  When they are big enough to emerge as adults, they crawl up out of the pond, their backs crack open, and the adult simply crawls out of the exoskeleton of the naiad form.  (Because there is no pupal stage, this is called Incomplete Metamorphosis.)  As adults, they spend only one season eating other insects, finding a mate, and laying eggs.  Sometimes you can find the shed exoskeletons (or exuviae) in the vegetation near ponds.

P.S.  Many thanks to Flickr friends for the use of their photos for this blog posting.  I hope you will all click on over to their photostreams to see their other amazing work.

Update:  click here for more on dragonfly eggs.

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11 thoughts on “Dragonfly Sex

  1. Pingback: Dragonfly Eggs « A Passion for Nature

  2. I thank you as well as I’m writing an interpretation of a poem “Last Night” which uses the dragonfly as a metaphor. Thanks it really helped me pull it together.

  3. I’ve been told that its possible to identify the sex of an exuvia from ‘a depression on the second segment’ of the abdomen’. Is that correct and Is there a helpful photo? I’ve collected about 20 Libellula exuvia from a wall next to my pond.

    • Wow. You are hard-core! I had not heard that. But I’ll pass the question on to a buddy who might know. The second segment of the adult is where you can tell gender… and I suppose there could be a difference on the exuvia. But I’ve never looked.

      • I’m definitely not ‘hard core’. I know next to nothing about dragonflies other than what happens at my pond. I noticed that all the emerging dragonflies were the same greenish yellow, while the male that commandeered my pond later was blue. A knowlegeable friend explained and told me that male and female exuvia could be distinguished. But I’ve noticed almost no differences on segment two of the 20-odd exuvia I’ve collected..

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