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.

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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.

08 MAY 2015 | Huntley Meadows Park | Southern Spreadwing (male)

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”).

08 MAY 2015 | Huntley Meadows Park | Southern Spreadwing (male)

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).

Related Resources:

• Another new species of spreadwing damselfly…
• A Southern Fortnight, Part 1 – Year-long mystery solved!
• A Southern Fortnight, Part 2 – Damselfly terminal appendages (male)
• A Southern Fortnight, Part 3 – Southern Spreadwing damselfly (male)
• A Southern Fortnight, Part 4 – Southern Spreadwing damselfly (female)
• A Southern Fortnight, Part 5 – Southern Spreadwing damselflies (mating pairs, in tandem)
• A Southern Fortnight, Part 6 – Damselfly reproductive anatomy
• A Southern Fortnight, Part 7 – “Arty”

Copyright © 2015 Walter Sanford. All rights reserved.

Tags: cerci, claspers, Eastern Pondhawk dragonfly, Erythemis simplicicollis, Family Lestidae (Spreadwings), hamules, Huntley Meadows Park, Lestes australis, Lestes forcipatus, male, paraprocts, predator, prey, Southern Spreadwing damselfly, Sweetflag Spreadwing damselfly, terminal appendages, wildlife photography