HARMVECT-a simulation-based tool for pathway risk maps of invasive arthropods in Belgium

HARMVECT is a tool simulating the introduction of arthropods into Belgium. Via simulations of the potential introduction pathways the tool calculates risk indices which are used to generate pathway risk maps for Belgium. An essential approach is the tool’s design in guiding the user in dividing the complex arrival of the arthropod into potential pathways (e.g. trade host commodities, human transfer, natural spread, import), which in their turn are further subdivided into individual pathway-segments based on decisive aspects like e.g. transport mode and origin of the transport course. The manageable and singular segments are then used to specify the detailed data the user has to gather and feed to the tool. This data is used to simulate the arthropod's introduction and calculate risk indices related to arrival via the various pathway segments; risks are based on propagule pressure. The tool generates 2 types of pathway risk maps: (a) a Point-Of-Entry pathway risk map (POE); this map, generating concentrated hotspots, is based on entry at the national borders, and (b) a Point-Of-Appearance pathway risk map (POA); this map is successive to the POE and visualizes the locations and level at which undetected propagules of the arthropod are exposed to the outside environment throughout Belgium. In conclusion, the tool produces a risk map for the arthropod’s potential establishment, which is generated by combining the POA with a climate-suitability and host-availability map.