I have a peach tree in my yard covered in white flies is this going to kill my tree and will I be able to eat the fruit this year?
They will almost certainly reduce the crop. The flies should be killed before they deposit eggs which will become larvae and attack the tree.
A plant oil insecticide will kill them and leave the fruit safe to eat.
Make sure the ground under and around the tree is free from dead leaves and other decaying debris. Don’t over mulch and definitely don’t make a volcano pile of mulch around your trees. Never let mulch touch your trees.