• A high quality survey to determine the outer boundaries of an area infested by the pine wood nematode (PWN) is important as it will form the basis for decisions with large consequences.

• A strategy for a delimitation survey is developed taking into account Swedish climate conditions, current forestry operation practices and the biology of beetles vectoring PWN.

• The proposed survey offers the possibility of determining which level of PWN-infested objects that shall be detected and with which statistical reliability. Sampling of Monochamus-colonized logging residues on clear-cuts and in pre-commercial thinnings is conducted in zones around the location of the original detection of PWN.