While those of us working in the Beatty Collection love featuring some of the really interesting specimens we encounter, we also enjoy sharing some of the basics of Odonata morphology with others who may not be fortunate enough to work with them everyday. This week we will be having a brief discussion of a defining character of dragonflies and damselflies, their wings.

While I could devote an entire series of blog posts to the selective pressures upon odonate wing shape evolution, I will instead focus today on the major morphological differences between the Anisoptera and Zygoptera wings. While both have fore- and hindwings, there are some obvious differences that enable identification even by an amateur odonatologist.

1. Orientation When encountering an odonate in the field, the quickest way to determine if it is a dragonfly or a damselfly is to observe the wing position at rest. A dragonfly will be at rest with wings spread laterally, perpendicular to the rest of the body. A damselfly will usually be at rest with wings together and in line with the abdomen (Dudley 2000).

2. Wing Size Anisoptera have basally expanded hindwings with smaller forewings, while Zygoptera typically have fore- and hindwings of a similar shape and size (Wootton 1992).

3. Motion Dragonflies in flight look strong and intentional, while damselflies tend to look delicate and fluttery (Wakeling & Ellington 1996). Hear the sound of the dragonfly in flight here. It might surprise you with how fast and strong it sounds!

I hope that this has been helpful as a basic guide for those readers who have always wondered about how to tell the difference between dragonflies and damselflies!