Spore traps need improvement to fulfil plant biosecurity requirements

Spore traps are widely used in plant pathology, but less so in plant biosecurity. Potentially they can be used to determine the geographical extent of a plant pathogen incursion, to track the active spread of an incursion, and to declare area freedom following an eradication program. This review discusses the abilities and constraints of spore traps in the context of plant biosecurity, and highlights the problems that need to be overcome before spore traps can be routinely used for detection and eradication of plant pathogen incursions. To meet biosecurity requirements, spore traps must be efficient, mechanically reliable and any spores captured must be rapidly identified and quantified. At present, there is significant variation in types of spore traps, and in the methods used to capture and identify spores. Standard spore traps are generally inefficient for surveillance because they do not sample large volumes of air or capture samples that are representative of entire crop growing regions. If spore traps are to become routinely used for plant biosecurity purposes, improved designs, novel applications and standard operating protocols must be developed. A better understanding of background atmospheric data and the spatial and temporal characteristics of pathogen spores will be required to design trapping systems and protocols so that incursions can be readily detected, and presence/absence data can be confidently reported.