What is the name of an insect that only appears once every 17 years has 6 legs when their adults they have wings it eats mostly roots It lives undergroud doesnt have a stinger and isn't a wasp?

You are thinking of the cyclical or 17-year cicada. They are large, plant-feeding insects which have clear wings and are known for making a very loud noise.
It is not clear why this insect comes out every 17 years, but scientists believe it has something to do with survival. As billions of cicadas emerge at about the same time, it is impossible for predators to have a significant effect. Birds may eat their fill of cicadas, but how many can they eat in a month?
Cicada juveniles are called 'nymphs' and live underground, sucking root fluids for food. During the 17 years, they go through five different stages, growing from the size of an ant to almost as large as an adult. (25-50mm). In the spring of the 17th year, the nymphs construct an exit hole about ½ inch in diameter to the surface then emerges at sunset, finds some vegetation, and molts into an adult. After about a week the cicada becomes active.
Cicadas are harmless to humans and animals but do some damage to trees. After mating, the female lays eggs on outside branches of many trees such as dogwood, crabApple, oak, and maple. At the point where the eggs are laid, extending to the tip of the branch, the branch will usually die. When hundreds of cicadas invade a tree, the dead branches will show up about a month later. Although unsightly, this damage is minor and the tree will recover. However, newly planted trees could possibly be killed if enough damage is done.