I found several of these bugs in my pond (located in Northern NJ) while doing repairs to it today. It tends to swim to the bottom and bury itself under the rocks or it floats to the top. They are all about 1 inch or less in length. Since restoring the pond last year (it was filled in 25 ago) several species have returned including this guy and I would like to know if it a pest or friend? If it is a pest, what other insect, bird, etc can I attract to control them? Thanks!
This is a Backswimmer, a Water Bug in the family Notonectidae. They are predators that eat insects that fall into the water as well as aquatic insects, tadpoles and small fish.