The following gallery of photos features a Slender Spreadwing damselfly (Lestes rectangularis) spotted near a vernal pool at Huntley Meadows Park (HMP). This individual is a female, as indicated by its terminal appendages and the ovipositor located on the underside of the posterior abdomen. The ovipositor is used to insert eggs into vegetation (endophytic oviposition).
See a full-size version of the preceding photo, without annotation.
Look closely at the tip of the female’s abdomen. Notice a couple of anatomical structures: two cerci (sing. cercus), superior appendages that have little or no function; and two styli (sing. stylus), structures that serve as sensors (like “curb feelers“) in egg positioning during oviposition.
See a full-size version of the preceding photo, without annotation. Adobe Photoshop was used to remove a couple of small distracting elements from the photo.
The last two photos provide a good side view of the ovipositor.
Related Resource: Odonate Terminal Appendages.
Copyright © 2015 Walter Sanford. All rights reserved.
Tags: cerci, Family Lestidae (Spreadwings), female, Huntley Meadows Park, Lestes rectangularis, oviposition, ovipositor, Slender Spreadwing damselfly, styli, terminal appendages, vernal pool, wildlife photography