With increasing efficiency in human and freight transport fuelled by the creation of the global market place, pressure is mounting on quarantine administrators to target their resources strategically. A managed approach to decision-making is therefore becoming an integral part of quarantine management since target species and/or entry pathways must be identified and policed effectively. Using the example of Melon Thrips in Western Australia, this paper presents an economic framework that allows decision-makers to prioritise exotic pests based on the damage and production cost increases they are capable of imposing on affected industries. In doing so it identifies a critical level of expected damage associated with the pest that can then be used as a ceiling for incursion response expenditure.