The Maximum Pest Limit Concept Explained

Fig. 1. Sampling to comply with a maximum pest limit, based on the cost to the exporter. The figure shows a graphical interpretation of equation 6 from Baker et al. (1), with m=3, N=208550, µ=40, s=10-4.5, =0.95. The dashed line (- - -) shows the probability that the consolidated consignment is below the maximum pest limit after treatment, Pr(B), as a function of the proportion of fruit infested p. This line intersects with 0.5 (shown by a solid horizontal line) at p*=0.0041, characterizing the critical incidence of infestation for the selected parameter values above. The dotted line (---) shows the probability that the pest is detected in the sample 1-Pr(A) as a function of the proportion of fruit infested p, with Pr(A)=e-np. The sample size n is chosen so that 1-Pr(A) as a function of p intersects Pr(B) as a function of p at the previously identified critical incidence of infestation. The solid bold line then shows the probability that the consolidated consignment is below the maximum pest limit after treatment and that the pest is detected in the sample Pr(B)×[1-Pr(A)] as a function of p. This probability has a value equal to at the critical incidence of infestation.



Image from Plant Health Progress article:
The Maximum Pest Limit Concept Explained