Key features and identification terms for dragonflies

Glossary

Abdomen   

Longest part of the body behind the thorax. Varies in size and shape especially in dragonflies.   
   

Anal appendages   

The pair of claspers which protrude at the end of the male’s abdomen used to grasp the female during copulation.

Antehumeral stripes   

The ‘shoulder’ stripes that run horizontally down the thorax of many species and very important in identification.  A good example is the Southern Hawker which has think obvious stripes.

Costa   

The leading edge of the wing, sometimes coloured and can be a useful identification aid. Especially prominent in species such as Migrant Hawker and Hairy Dragonfly

Exuvia (exoskeleton) 

The shell of the larvae left after the adult dragonfly has emerged & often attached to emergent plant stems. See photo opposite.


Immature   

A young adult that has not yet reached maturity; usually they often have very different colours to adults. Young males can often resemble mature females.

Larvae or nymph   

The aquatic stage of the dragonflies life cycle before emerging as an adult.

Ovipositor   

The spine or blade like structure that is found underneath the female between segments 8 – 10. It is used to lay eggs directly into the water, plant tissue or even damp wood.

Pruinescence   

A waxy like bloom which develops on the abdomen of adults, giving them a powdery blue appearance, for example the male Scarce Chaser.

Teneral   

After emerging, the stage when the adult body is still soft, colours are very muted and wings extremely shiny. See wonderful example opposite of an Emperor Dragonfly.


Thorax   

Most robust part of the insect, connecting head to abdomen and where wings are attached. Stripes on top of thorax (antehumeral) and at sides are very useful for identification.

Wing-spot   

Technically known as the ‘pterostigma’ this is a small cell of the wing on the leading edge often dark or coloured. All species have them.

Exuvia (photo © Jane Adams)

Teneral Emperor Dragonfly (photo © Trisha Thomspon)