[Odonata-l] Absent nymphs
Wed, 18 Jun 2003 09:24:49 -0700
Joe Ackerman wrote:
>I have been sampling retention ponds for Odonata for 2 full summers.
>This spring, a large pond is completly void of all forms of Odonata
>nymphs. The pond is 2 meters deep and about 4 acres in size with
>cattails around the shoreline. Over the last 2 years 7 species of
>Zygoptera and 6 of Anisoptera have been found, and always by this
>time of year.
>The only thing I can think of is winter kill due to a hard winter
>but the rest of the insect population seems intact as does the fish
>Has anyone seen this sort of complete change from one year to the next?
Joe, I've never heard of such a thing. If the fish and other insects
are still there, I can't imagine a reason the odonates aren't; it
obviously didn't dry up. It represents a real anomaly to me, and I'd
be interested to hear what transpires during the rest of the summer.
Dennis Paulson, Director phone 253-879-3798
Slater Museum of Natural History fax 253-879-3352
University of Puget Sound e-mail email@example.com
1500 N. Warner, #1088
Tacoma, WA 98416-1088