A Southern Fortnight, Part 2 – Damselfly terminal appendages (male)

The Backstory: A Southern Fortnight

For the first two weeks during May 2015, Southern Spreadwing damselflies (Lestes australis) were observed at a vernal pool and nearby drainage ditch in the forest at Huntley Meadows Park. I spotted approximately six males and several females during the fortnight. Their sudden disappearance seemed to coincide with a population explosion of Eastern Pondhawk dragonflies (Erythemis simplicicollis) in mid-May. Eastern Pondhawks, especially females, are voracious predators with a penchant for preying upon damselflies.

All male damselflies have four terminal appendages, collectively called “claspers.” Male damselfly terminal appendages don’t look exactly the same for all species of damselflies, but their function is identical.

Claspers are used to grab and hold female damselflies during mating: an upper pair of cerci (“superior appendages”) and a lower pair of paraprocts (“inferior appendages”).

Damselflies, including the larger members of the Spreadwing Family, are smaller than dragonflies. Please look at the full-size version of each annotated image in order to see critical details that cannot be seen in the preceding thumbnail versions.

For example, the first image shows the male hamules, …

paired structures that project from pocket under the second segment and hold female abdomen in place during copulation. Source Credit: Glossary [of] Some Dragonfly Terms, by Dennis R. Paulson.

The hamules are key field marks for differentiating some species of similar-looking damselflies, such as Southern Spreadwing (Lestes australis) and Sweetflag Spreadwing (Lestes forcipatus).

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Copyright © 2015 Walter Sanford. All rights reserved.

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6 Responses to “A Southern Fortnight, Part 2 – Damselfly terminal appendages (male)”

  1. Southern- or Sweetflag Spreadwing? | walter sanford's photoblog Says:

    […] Spreadwing damselfly (Lestes forcipatus). It is a male, as indicated by its terminal appendages: Southern Spreadwing; Sweetflag […]

  2. Voltinism | walter sanford's photoblog Says:

    […] The following photo shows the only Southern Spreadwing observed at the study site during Spring 2016. This individual is a male, as indicated by his coloration and terminal appendages. […]

  3. Southern Spreadwing at MNWP | walter sanford's photoblog Says:

    […] The next two photos show a couple of males, as indicated by their coloration and terminal appendages. […]

  4. Top 10 Photos of 2016 | walter sanford's photoblog Says:

    […] 27 SEP 2016 | MNWP | Southern Spreadwing (male) […]

  5. Voltinism, revisited | walter sanford's photoblog Says:

    […] 18 APR 2017 | Mason Neck West Park | Southern Spreadwing (male) […]

  6. Pop quiz answer key | walter sanford's photoblog Says:

    […] Neck West Park, Fairfax County, Virginia USA. Both individuals are male, as indicated by their terminal appendages and blue […]

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