Dormant spraying involves applying a preventative spray early in the spring while the tree is still dormant. Dormant spray is typically comprised of two products which can be applied together or separately. One product is dormant oil and the other product is lime sulfur. Spraying now greatly reduces the impact these insects can have later in spring. Lime sulfur is a fungicide which kills dormant fungus spores on plants. : http://www.theflowerbin.net/media.html.