Dragonflies are beneficial to the garden. Their main food source is insects that can be damaging to plants and annoying to people, including mosquitoes and a variety of flies. You may be able to reduce commercial pesticides and mosquito repellents!
I love dragonflies and damselflies. You can tell the difference when they rest on a plant. The dragonfly will keep his wings open, while the damsel fly closes hers against her back. I also think the damsel fly looks more delicate! Azure Damselfly