Figure 3.

The outcome of field validation of risk maps. A map of southern Quebec showing the locations (unfilled or blue-filled circles) of CSDs in which field study sites were visited. The 'index of certainty' for the presence of an I. scapularis population was calculated from the abundance of ticks and the numbers of instars discovered during the field visit. The value 0 indicated that no I. scapularis ticks were found. The 'high' risk regions for I. scapularis population establishment are indicated in red, the 'moderate' risk regions are in orange, the 'low' risk regions are in yellow, and regions with no risk of established populations but some risk from bird-borne 'adventitious' ticks are in green