[Odonata-l] Tail-dipping Female Octogomphus (Grappletail)

[Jim Johnson]

Hi Glenn,

Kennedy's description of ovipositing Octogomphus--being entirely aerial
while tapping the water, is what I think of as typical behavior for the
species and not something intermediate.

I received a response from Steve Rottenborn of Los Gatos, California, who
stated that he recently saw a female exhibiting the same behavior as the
Gold Lake females, but he couldn't see if she was ovipositing since she
flushed as he approached. He described the Octogomphus densities on the
stream as very low (three individuals over several hundred meters of
creek--which is less than what I think of typical density over most of its
range in the Northwest). So that suggests that the behavior is not the
result of very crowded conditions.

Jim Johnson
Vancouver, Washington
jt_johnson at comcast.net
http://odonata.bogfoot.net/
 

-----Original Message-----
From: Glenn Corbiere [mailto:gcorbiere at dragonhunter.net] 
Sent: Tuesday, July 21, 2009 11:58 AM
To: Jim Johnson
Cc: Odonata-L
Subject: Re: [Odonata-l] Tail-dipping Female Octogomphus (Grappletail)


Hello Everyone,

What better way to pass a rainy vacation day than pondering the life
histories of dragonflies.

It can be extremely difficult to find various life history details on so
many dragonflies. It's frustrating looking at old books and finding almost
nothing other than descriptions.

After spending an hour or so looking at various refrence works, I could not
find any mention of Octogomphus specularis ovipositing by dropping eggs
while in flight, at least not exactly. I did find this quote from Clarence
Kennedy from an article published in 1917 entitled "Notes on the Life
History and Ecology of the Dragonlfies of Central California and Nevada". It
describes a behavior not quite what Nick Donnely and Jim Johnson observed,
but somewhere between what they observed and dropping eggs in flight.

"After having spent various days wading down mountain streams observing
Octogomphus more often than catching them, I was rewarded on July 7 by
seeing a female oviposit. She came volplaning down through an opening in the
canopy of alders and, while going through evolutions involving several
figures, 8's and S's, she touched the surface lightly with the tip of her
abdomen at intervals of 2 to 6 feet. After 20 seconds of this she airily
spiraled up and out into the sunshine, where she alighted on a bush on the
hillside above the creek."

Incredible prose, isn't it? Makes you want to read the entire article. You
can find it online in Google Books, which is itself an incredible resource
for old books and articles. (Volplaning sent me to the dictionary.)

I've been waiting for some time for a discussion along these lines.
Supposedly, the Ophiogomphus clan oviposits in a similar way to what
Clarence Kennedy described for Octogomphus.  Believe it or not, the only
description I could find about this came from the same 1917 article by
Kennedy.

"In ovipositing the female deposits the eggs in swift water, usually on
rapids, where she flies back and forth dipping the tip of her abdomen in the
stream."

By the way, both of the above quotes are reproduced in Needham and Heywoods'
"Handbook of the Dragonflies of North America" published in 1929, the
forerunner of Needham, Westfall and May's "Dragonflies of North America",
Revised Edition of 2000.

I want to relate what I observed with Ophiogomphus mainensis six years ago.
I was at beautiful stretch of the rocky West Branch of the Westfield River
here in Chester, Massachusetts. I was watching a snaketail flyh about when
to my surprise, it suddenly plunged into the river and started floating
downstream on the swift current. I had no idea what was going on here, and
thought it was a very strange behavior. The dragonfly floated with the
stream between two rocks, and paused there for perhaps a half minute or so,
at which time I snapped a couple photos. At that point I could see it was a
female. Then the water seemed to win out again, and she continued floating
downstream. She washed up against and over/around small rounded and
protruding rock, and she held on. The front part of her body was on the
rock, her abdomen trailing in the water. I snapped a few more photos before
she sprung up and flew on her way. When I looked at the photos later, both
 when she was stuck (or so I though) between the two rocks, and hanging on
to the small rounded rock, I could see eggs drifting back from her abdomen,
trailing strings. I've had a photo posted on my web site since then, but I
sized it up a little for older eyes (not unlike my own). The photo is not as
sharp as I would like, but if you look closely I think you'll see an egg
trailing from her abdomen:

http://www.dragonhunter.net/ogomphus_mainensis_f_ov_lg.html

What I don't know, since I didn't manage any photos while she was
freefloating with the current, but I suspect, is that she was ovipositing
during her entire journey on the water.

Every year since I am often in areas with abundent Ophiogomphids of a few
different species, but I have never observed this behavior again. I don't
know if it is a usual way for them to oviposit, or if this was somewhat of
an anomoly. I can only speculate here, but my speculation is that it was not
an anomoly.



Glenn Corbiere 
100 Prospect St. 
Chester, MA. 01011-9657 

www.dragonhunter.net