T-Mark Emerald Dragonfly - Hemicordulia tau
FAMILY CORDULIIDAE - Emerald
- Body length 50mm
This page contains information and pictures about T-Mark Emerald Dragonflies that we found in the Brisbane area, Queensland, Australia.
- Take a closer look of the dragonfly's face. There is the inverse black 'T' mark on its 'nose'. This is why those dragonflies are call T-Mark Emerald. Some other dragonflies also have the inverse 'T' mark on their face, such as the Yellow Emperor dragonflies. The T-mark is also the easy way to distinguish them from Australian Emerald. Australian Emeralds has their face black with metallic blue-green reflections.
- Like all members in this dragonfly family, when perched, they usually hang suspended vertically. They rest high on trees at night.
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- The T-Mark Emerald Dragonfly has two pair of wings which are about equal in size. They are clean in colour. It veins pattern are the same as Australian Emerald but veins colour is yellow brown, while the Australian Emerald is black in colour.
The T-Mark Emerald Dragonflies are medium in size, body length about 50mm. They look very similar to another Emerald species Australian Emerald. They can usually be found in the same place. Because both of them never rest, it is difficult to distinguish between them. Their bodies are long and slender, with black pattern on yellow colour. They have two pairs of membranous wings, about the same size.
Questions for Discussion
Why the dragonflies' eyes colour keep changing?
- The colour of dragonfly's eyes are usually bright in colour. However, the colour is subjected to fade. The colour become dull if the dragonfly is captured and keep for a few hours. If the dragonfly is dead, its eyes' colour become dull and dark. What keep the dragonfly's eyes bright in colour? Why it become dark when the dragonfly is dead?
