Some species of dragonflies display sexual dimorphism; females are polymorphic for a smaller subset of those species. Andromorph females are male-like in color; heteromorph females are duller in color than males.
Terminal appendages are important field markers that may be used to differentiate adult males and adult andromorph females of the same species.
Andromorph female Blue-faced Meadowhawk dragonflies (Sympetrum ambiguum), like the one shown below, are less common than heteromorph females. Andromorphs have a red abdomen with black rings, like male Blue-faced Meadowhawks; unlike males, most female faces are tan and their terminal appendages look different than male appendages.
The following photo shows a heteromorph female Blue-faced Meadowhawk dragonfly. Heteromorphs have a tan abdomen with black rings.
Polychromatism has often (inappropriately) been termed polymorphism. I follow the terminology recommended by Don Hilton (1987), in which the female coloration is termed gynochromatypic and that of the male androchromatypic. Source Credit: Corbet, Phillip S (2004). Dragonflies: Behaviour and Ecology of Odonata. [The 1962 edition of the book is available online: A Biology of Dragonflies.]
- Dragonfly terminal appendages (male, female) [Painted Skimmer]
- A sampler of male dragonfly claspers (Part 1)
- A sampler of male dragonfly claspers (Part 2)
- Odonate Terminal Appendages
Copyright © 2015 Walter Sanford. All rights reserved.