Manila copal has been an important cash crop for many rural people in the tropical Far East. In response to strong demand from industrial nations, destructive tapping increased production. There were reports of Agathis trees being killed over large areas of Indonesia and attempts were made to introduce controls in the 1930s. Trees respond to intensive tapping by forming cancerous growths. As of 1980, the island of Irian Jaya was the principal Indonesian source of Manila Copal. Trees are utilized only for resin. Small plantations have been established and the Forest Department controls the industry that has developed a non-damaging tapping system. A resin tapping industry is also being developed in the Sepik River drainage in north-western Papua New Guinea