Dragonflies are insects in the sub-order Anisoptera (meaning “unequal-winged”).
The term ‘dragonflies’ is sometimes used for the whole scientific order Odonata that also includes the sub-order Zygoptera (damselflies).
Characteristics Of True Dragonflies
Body: Large and robust.
Wings: Hind wings are usually shorter and broader than the forewings.
Eyes: Very large and usually touch at the top of the head.
Southern Hawker image by Christophe Brochard
Body: often thinner in the abdomen with a narrow ‘waist’ near the top of the abdomen.
Accessory genitalia: Used for transferring sperm to the female during copulation. Located under segment 2 of the abdomen.
Anal appendages: Visible at the very end of the abdomen.
Male Southern Hawker dorsal image by Airwolfhound
Male Southern Hawker side image by Ian Preston
Body: Often thicker in the abdomen.
Ovipositor: Appendage used for egg laying. Located under segment 8-9 of the abdomen.
Female Southern Hawker dorsal image by Ian Worsley
Female Southern Hawker side image by Ian Preston
In many species of dragonflies adults change colour as they mature.
Tenerals: Newly emerged adults are often paler in colouration.
Mature adults: As an adult becomes sexually mature this is often indicated by a change in coloration.
Over mature: In some species, adults become darker in coloration as they age.
Mature Female Common Darter image by Andrew Holloway
Over-mature Female Common Darter image by Charlie Jackson
Mature Male Common Darter by Suzy Shipman
Title image: Black Darter by Iain Leach