FIG. 3.

Proportional membership of each Tria. infestans sample in clusters for K = 3–7 as identified in STRUCTURE. Individuals from the Quequeña district are separated into two distinct groups at all values of K, one of which is comprised of individuals assigned to a cluster not found in other districts. The other districts are comprised of bugs from the same clusters but at different frequencies. The most likely estimate of K is 4, as determined by the ΔK method (Evanno et al. 2005).