We have an incredible variety of dragonflies and damselflies in our area in NY.
I do not use insecticides because the chemicals are harmful to bees, butterflies, dragonflies, ladybugs (aka ladybird beetles (Coccinellidae), which hibernate under the siding of our house during winter), praying mantisses, walking sticks, ants and a variety of other beneficial insects, as well as birds. Consequently we have an abundance of beneficial insects.
Incidentally, we have very few harmful insects. During June, I have to manually remove Japanese beetles from my raspberries and other plants. I certainly cannot use insecticides because 1) that is the same time bees are pollinating the flowers and collecting pollen, and 2) I don't want to expose my family, myself, our pets, and the wildlife which visit our yard.
Spiders, ants, preying mantisses and a host of other insects keep the undesirable insects in check.