|Blue dasher, male|
Nearly 30,000 lenses make up its compound eye, the dragonfly a 360-degree field of vision.
|On the fly|
|With Yellow iris (Iris pseudacorus)|
|Blue dasher, female|
|Depositing eggs while hovering|
|A vacated nymph case|
|An emergent adult with nymph case|
|The new adult spreading its wings|
|The 'obelisk' position|
|A water lily perch|
Blue dasher on
When hovering, the dragonfly's wings stroke back and down independently in a kind of rowing motion that creates vortices of air and upward drag. Complex fluid dynamics are instrumental in keeping its body stationary. The efficiency of the wings is increased by their capacity to flex and twist with the air. This natural action conserves energy that the insect would otherwise have to use to effect such turns by exercising muscles. The wings in the foreground also show a solidly colored (dark) cell called a pterostigma, which by its slightly heavier construction helps dampen vibrations and assists in gliding.From the Universities Space Research Association's website.