 |
 |
|
 |
|
 |
|
|
 Larval Stage
- Most of the time the dragonflies remain as larva stage during their life history, and it is also the major growth period for them. They have to shed their external skeleton (exoskeleton) before they can grow bigger. Depends on different species and environmental conditions, dragonfly larva may pass through 9 to 17 stages. After each moulting, larva swallows large amount of water or air to enlarge the new naiad exoskeleton for increasing their dimensions.
- When the larva grows to a certain body size, it will start to emerge, which will turn it into the last stage of dragonfly, the adult stage, normally it will wait for the suitable environmental factors (temperature, humidity, etc.). Before a larva emerges, the mouth part of it will change in structure which makes it stop feeding. To prevent being hunt, larva prefer to emerge during midnight or dawn. It will climb up the stem of aquatic plants or to the rock surface out of the water. Sometimes, some larvae may even climb up to 30 meters above the water surface before emergence starts.
 |
An exuvia left behind clinging to a pole after a Pale-spotted Emperor emerged |
|
 |
A damselfly hangs on Equisetum after emergence, waiting for its wings to dry |
|
Mating
 |
A heart-shaped wheel is formed
during copulation |
- Most animals use different ways to attract mates for reproduction, for example, some waterbirds have beautiful breeding plumage, firefly lights with specific frequencies, Danaid butterflies produce pheromones, etc. However most dragonflies act straightforward when located its mate - the male dragonfly will simply fly near the female and grasp it with its claspers. The female dragonfly will then bend her abdomen upward and forward to engage its tip with the male's secondary sexual organs, forming a heart-shaped wheel, and they will begin to copulate.
 |
Dragonflies still keep in tandem
linkage after copulation |
- Normally, the male will hold the female in tandem linkage or remains in close distance. These guarding action can prevent other males to court with the female. In addition, male dragonflies also have body structure like hooks or barbs to remove rival, sperm of others males inside the females' body.
Thermo-regulation
 |
Dragonfly points its abdomen
towards the sky in hot sunny day |
- On a hot sunny day, dragonflies will point their abdomen towards the sun to minimise the surface area of its body in direct contact with sunlight. Dragonflies can also adjust the position of their bodies according to the sunlight direction.
- On a cool day, dragonflies increase their body temperatures by basking on rocks or bare soil, which are good in heat radiation.
|
|
 |
|
|
|
|
