The version of this article that was originally published contains an error in the description of the formula used to calculate ProbArr (p322). This error does not change the results of the calculation in used in this paper but the paragraph should read as follows:
Calculation of ProbArr.
For endemic established pests this value is set to 100 per cent as the P&D is already established. Otherwise for P&D threats yet to arrive in geographical area (g) the percentage is estimated by the equation: 100/estimated earliest year of arrival of PD in geographical area (g) For example, if a P&D is estimated to arrive by year 20 then the annual probability of arrival (ProbArr) would be 100/20 = 5 per cent.
