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Dragonfly Claspers & Genitalia

In-hand examination of the genitalia and abdominal appendages is necessary for identification of some of the hard to identify species, as kinky as it might sound! To do this takes some practice, patience, a magnifying lens, and some basics of dragonfly anatomy. Many field guides incorporate illustrations of appendages  to make this easier. Dragonflies of North America, by Westfall and May, has scans of most species.

Dorsal and lateral view of the abdominal claspers of a Shadow Darner, Aeshna umbrosa

The tip of the male abdomen has appendages, often called claspers, that are diagnostic for most species, especially the Darners, Clubtails and Emeralds.  Females have terminal appendages but these are rarely of use in ID except in a few cases where their length may be significant.





Scans of secondary genitalia of a Whiffling Meandowhawk and a Sniffling Meadowhawk

In a number of species, especially among the Skimmer family, these terminal appendages don't vary much between the species. In some of these, the secondary genitalia under abdominal segments 1&2 may be of some help.  But learning to see them with a hand lens can take a bit of practice and even then some species are frustratingly similar or show variation within the species.

Ovipositor of a Fine-lined Emerald with eggs

Female dragonflies: Some females canbe identified by the shape of the sub-genital plate or ovipositor under abdominal segments 8&9.

To learn more about the names and function of these body parts, you can visit our biology pages.

© 2021 Sheryl Chacon Search