The white-fringed weevil (Naupactus leucoloma) is a major pest of potatoes in Australia. Grubs live in the soil where they cause devastating damage to the roots and tubers of crops. Increasingly, potato growers rely on the application of pre-plant insecticide sprays to insure against white-fringed weevil grub damage. However, the application of such sprays may be unwarranted if densities of white-fringed weevil grubs are too low to cause economic damage. To make informed decisions on the need to spray insecticides, it is necessary to accurately determine the density of white-fringed weevil grubs present in a paddock using a reliable sampling plan. Such a sampling plan has been developed for mainland potato crops but has not yet been tested for Tasmanian populations of white-fringed weevil nor has it been adequately extended to all Tasmanian potato growing districts. Currently, there is no alternative method for monitoring white-fringed weevil populations in crops other than sampling for grubs in the soil. Recent research has shown that the grubs of many subterranean insects, detect and orient towards specific volatile compounds released from their host-plants. This report details Project PT09027 which: A) Evaluated and extended the existing white-fringed weevil grub sampling plan to Tasmanian potato growers; B) Conducted novel research to determine how white-fringed weevil grubs detect the presence of host-plant roots in the soil.