Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract Full Text

Weed surveillance using search theory.


The success of a weed incursion response ultimately depends on the ability to find and kill individual plants. Understanding detectability will allow development of operational models to guide eradication efforts by allocating resources as efficiently as possible. We present the basics of search theory to show why obtaining a measure of detectability can help us develop effective tools for allocating surveillance resources. This is particularly important in the context of new methods of searching for weeds becoming available. The use of detector dogs, remote sensing, drones and other tools provide new opportunities to improve efficiency, but the right mix of methods will depend on the cost to achieve a given probability of detection. We use examples from existing weed eradication responses to show how detectability is affected by environment, search mode and life stage of the plant. We conclude by proposing ways of making these decision-analysis principles more accessible to practitioners.