Pine wilt is a serious disease of pines, especially Scots pine, in the Midwest, including Iowa.
Infected trees wilt and die within a matter of weeks to a few months.
Although a nematode is the primary disease agent that blocks water flow in affected trees, pine sawyer beetles are the vectors that carry the nematodes from infected to helathy trees. The major recommendation to help control spread of the disease is to remove infected pines promptly and burn, chip, or bury them. A recent research article in the Journal of Nematology demonstrated that the nematode which causes pine wilt can survive for brief periods in wood chips, and can even enter healthy trees if fresh chips are in direct contact with wounded roots or stems . A scenario in which this could possibly occur might be when fresh chips from an infected tree are incorporated into the soil around a newly transplanted Scots pine, because digging and transplanting typically creates root and even stem wounds. The risk of transmission from infected chips is probably very small even under this scenario.