A menu of measures to manage trade-related plant pest risks, and a review of methods for demonstrating measure efficacy

Abstract

Ever-increasing global trade is one of the most important introduction pathways for plant pests. A diverse range of risk-reducing measures can be applied depending on the pest, the commodity and the import requirements. We used a review of over 1,800 risk reduction measures to extend a risk framework and menu of measures, previously developed for horticulture, to be applied to any commodity. We also reviewed how the efficacy of risk reduction measures is demonstrated, and assessed the maturity of the supporting science. We identified 39 unique risk reduction measures that were classified according to how they reduce risk. These were grouped under ten measure categories and four risk reduction objectives (minimising exposure to pest, minimising vulnerability of the commodity, reducing infestation rate and reducing establishment risk). These could then be applied against one or more consignment stages (production, post-production and post-border). Measures covered both commercial activities that reduce risk and may contribute to pest risk assessment, and regulated measures mandated to address unrestricted risk. Almost 90% of citations included measures that minimised exposure to pests or reduced infestation. Some measures were rarely reported, and some commodity classes had few measures associated with them, suggesting that available measures are being underutilised. Clear guidance was apparent for demonstrating efficacy of some measures (e.g., kill treatments), but lacking for many others. Compiling a ‘menu of risk reduction measures’ according to how they reduce risk, accompanied by clear guidelines for demonstrating efficacy, provides a robust basis for agreement between jurisdictions, and the further development, refinement and communication of efforts to both assess and manage the risk of global, trade-related pest movement. Agreement on how efficacy can be demonstrated for less utilised measures identified in this study will contribute to the further development of risk-based trade.

Simulation to investigate site-based monitoring of pest insect species for trade

“…Global trade provides substantial economic benefit to participating countries, but also provides potential pathways for numerous plant pests and pathogens ( MacLachlan et al 2021 , Turner et al 2021 ). A wide range of measures can be applied to manage the risk of pests entering and establishing via trade pathways ( van Klinken et al 2023 , 2022 ). A commonly applied measure uses surveillance to provide confidence that pests are rare or absent on the registered site on which the traded article occurs ( van Klinken et al 2020 , 2023 ).…”

“…A wide range of measures can be applied to manage the risk of pests entering and establishing via trade pathways ( van Klinken et al 2023 , 2022 ). A commonly applied measure uses surveillance to provide confidence that pests are rare or absent on the registered site on which the traded article occurs ( van Klinken et al 2020 , 2023 ). Here we refer to registered sites as production or post-production businesses that are registered for trade such as orchards, farms, transport hubs, or sites on which packing, treatment, or storage facilities are located (see van Klinken et al 2023 ).…”

“…A commonly applied measure uses surveillance to provide confidence that pests are rare or absent on the registered site on which the traded article occurs ( van Klinken et al 2020 , 2023 ). Here we refer to registered sites as production or post-production businesses that are registered for trade such as orchards, farms, transport hubs, or sites on which packing, treatment, or storage facilities are located (see van Klinken et al 2023 ). These can include pest free production sites and pest free places of production as defined in ISPM 10 ( IPPC Secretariat 2016a ).…”

“…Surveillance design is an important element of pest freedom or low pest prevalence measures applied area-wide or within a registered site as it influences detection efficacy and cost. Area-wide surveillance generally focuses on providing confidence that pests are not present within the area, or do not exceed an accepted threshold ( van Klinken et al 2023 ), or on the detection and delimitation of nascent populations ( Caton et al 2021 ). In contrast, surveillance at the scale of the registered site needs to provide confidence that both pests already in the site and pests entering the site will be detected at sufficient sensitivity, even if there is no information available on adjacent source pest populations.…”

“…Providing confidence that pest abundance within a registered site does not exceed an acceptable threshold (e.g., pests per trap) is a key requirement for trade for many commodities ( van Klinken et al 2023 ). Here we test how pest detection sensitivity is affected by surveillance design when all traps can only be placed within the registered site of interest.…”