This gallery — named “practice oviposition” (egg-laying) — features a six-photo time series of a female Great Spreadwing damselfly (Archilestes grandis).
03 OCT 2017 | Huntley Meadows Park | Great Spreadwing (female)
Female Great Spreadwing damselflies, like all female odonates, have two cerci (sing. cercus), superior appendages that have little or no function. Also notice two styli (sing. stylus), structures that serve as sensors (like “curb feelers“) in egg positioning during oviposition.
03 OCT 2017 | Huntley Meadows Park | Great Spreadwing (female)
(See a full-size version of the original photo, without annotation.)
The female uses her styli to guide the ovipositor into position, as shown in the next two photos.
03 OCT 2017 | Huntley Meadows Park | Great Spreadwing (female)
03 OCT 2017 | Huntley Meadows Park | Great Spreadwing (female)
In this case, I saw no evidence that the ovipositor actually penetrated the tree twig. I think this was a practice run in preparation for the real thing, as the title of this blog post says.
03 OCT 2017 | Huntley Meadows Park | Great Spreadwing (female)
03 OCT 2017 | Huntley Meadows Park | Great Spreadwing (female)
Copyright © 2017 Walter Sanford. All rights reserved.
Tags: Archilestes grandis, cerci, Family Lestidae (Spreadwings), female, Great Spreadwing damselfly, Huntley Meadows Park, oviposition, ovipositor, styli, terminal appendages, vernal pool
walter sanford's photoblog 
October 15, 2017 at 6:11 am |
Wonderful series of shots and great explanation, Walter, of what you observed and were able to capture so beautifully.
October 15, 2017 at 8:31 am |
Thanks, Mike. If I hadn’t watched this damselfly for a long time then I wouldn’t have witnessed the unusual behavior.