[Odonata-l] nymph dying in pond

[Kathy &/or Dave Biggs]

  I'm hoping someone can help this woman who is finding dead nymph in 
her pond.
I'll paste in her messages:

    Hello Kathy,

    As I re-read your book "Common Dragonflies of California", this time
    I noticed your website on the back cover.

    I have had a small pond for about 7 years now, and have enjoyed
    gradually discovering the lifecycle of the dragonflies that have
    come to my pond.  The very disheartening problem I am seeing this
    year, more than ever before, is that most of the nymphs are dying,
    just when it looks like they are mature enough to climb up on a stem
    and transform themselves into dragonflies.

    So far this year I have found only 2 exoskeletons, while this
    morning alone, I fished out 3 dead little bodies floating in the
    water.  In an attempt to figure out why, I have tried the following:

    I have 7 pots in the pond, but only two of them have stems that
    stick out of the water (papyrus and water iris).  Is it possible
    that the nymphs cannot find an appropriate stem when they are ready
    to climb out?  I added 2 rough, weathered sticks into each of the
    other 5 pots.  So far, I have found nothing to indicate that any
    nymphs have climbed on the sticks.

    I use San Jose city water to "top off" the pond each morning. 
    Thinking that perhaps the chemicals in the water were killing the
    nymphs, for one week I used Aquarium AmQuel, a detoxifier that says
    it removes ammonia, chloramines, toxic pheromones and chlorine, each
    morning as I topped off the pond.  The nymphs continued dying on a
    daily basis.

    To clear cloudy water, I use Acurel E.  For the many years that I
    kept aquarium fish, I used the companion product, Acurel F, and
    swore by it, for keeping aquaiurm water clear and healthy.

    Have you encountered this problem?  Any ideas you have will be much
    appreciated!

    Sincerely,
    Gloria McClain

    Hi Kathy,

    Thank you for your very quick reply. Unfortunately, there is meat
    inside, and on their back it looks like rudimentary wings have
    started to come out. But they are quite dead --- I have tried
    putting them on a stem in case they might continue evolving, or
    crawl slowly back into the water. They don't. Their underside has
    turned kind of a pink color, and depending on how dead they are,
    their odor is left on my hands even though I did not squash them.
    The dogs find them to be a very tasty tidbit, if I leave them where
    the dogs can sniff them out and reach them. But they are not
    interested in the empty exoskeleton.

    My pond is in a very protected area of my back yard, and stays
    warmer than a more open area would. This spring I've seen orange
    dragonflies (sorry I can't be more accurate about which orange
    ones). Just a couple of days ago I watched one deposit eggs while
    hovering over the water. Its the first time I have seen that. All
    the others I have watched (in previous years) have landed on a
    stalk, just close enough to the surface of the water to stick their
    tail beneath the surface and it looked like they were sticking their
    eggs on the stalk, below the surface.

    Gloria

If you can help, please reply to whole group so we can all learn.
Thanks!!
Kathy

-- 
California Dragonflies	       http://www.sonic.net/dragonfly
Southwest Dragonflies		    http://southwestdragonflies.net/
Bigsnest Wildlife Pond	       http://www.bigsnestpond.net/
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Kathy and Dave Biggs	         bigsnest at sonic.net      707-823-2911
308 Bloomfield Rd.               Sebastopol, CA  95472 
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dba Azalea Creek Publishing      azalea at sonic.net   fax: 707-823-2911
http://www.sonic.net/~bigsnest/azaleacreekpublishing/ 
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