Sphaeropsis blight, previously known as Diplodia tipblight or dieback, is a major worldwide disease of pines, particularly of 2- and 3-needle pines in the United States from the East Coast to the Great Plains and the West Coast. It is mainly a disfiguring disease of trees growing under stress, with trees showing numerous brown, dead branch tips (Figure 1). Except for pine and white spruce (P. glauca) seedlings, Sphaeropsis blight rarely kills the host because only current-season needles, shoots (or candles), and seed cones are infected and killed. Where new candles have been killed several years in succession, however, entire branches may dieback from "resinous bleeding cankers."