This is one of our more common dragonflies.  They are also quite recognizable, the males anyway.  Males have the bright bluish white abdomen and the large black spots on the wings.  Females are totally different with a brown abdomen and three smaller black spots.  Common Whitetails can be seen early-mid summer into mid-fall hunting for prey along ponds, swamps, gardens, and parks.  Dragonflies are an interesting order of insects.  The head is oversized with large bulging eyes, to find their prey.  Their four wings can move independently, allowing the dragonfly to fly both forwards and backwards.  The legs are moved forward on the body, making it easier for the dragonflies to feed on their prey.  Dragonflies are closely related to damselflies, but typically dragonflies at rest hold their wings flat out while damselflies hold them straight up over their backs.