Damselflies

Definition

A suborder (Zygoptera) of predatory, aerial insects in the order Odonata, distinguished from dragonflies (Anisoptera) by their generally smaller size, slender build, widely separated compound eyes, and the habit of folding the wings together above the abdomen when at rest. Nymphs are aquatic and possess external gills in the form of three caudal lamellae. The group has a fossil record extending to the Late Jurassic and occurs in freshwater habitats worldwide except Antarctica.

Etymology

From Middle English 'damsel' (young woman, maiden) + 'fly', referring to the delicate, slender appearance compared to the more robust dragonflies.

Example

The common blue damselfly (Enallagma cyathigerum) perches with wings folded parallel to the abdomen, whereas the similar-sized common darter dragonfly (Sympetrum striolatum) rests with wings held horizontally.

Synonyms

• Zygoptera

Related Terms

• Dragonflies
• Odonata
• zygopteran
• caudal lamellae
• naiad
• pterostigma
• ovipositor

Usage Notes

The term 'damselfly' is vernacular for members of suborder Zygoptera; 'dragonfly' in the strict sense refers to suborder Anisoptera. Some authors use 'dragonfly' broadly for all Odonata, creating ambiguity. The wing posture at rest is the most reliable field character for separation, though exceptions exist (e.g., spreadwing damselflies in family Lestidae hold wings partially open). The three caudal lamellae of nymphs are diagnostic but require examination.