Figure 1.

Simulation-derived probabilities of six or nine mtDNA haplotypes being represented in different-sized groups of founder queens of S. invicta in the USA. Six haplotypes presently occur in Mississippi, whereas nine occur throughout the US range. Sources of the founders are assumed to be (a) Formosa or (b) Argentina (pooled Formosa and Corrientes samples). Simulations were run using both the uncorrected (observed) and corrected estimates of haplotype richness in the source populations. Black bars, six haplotypes, uncorrected richness; grey bars, six haplotypes, corrected richness; stippled bars, nine haplotypes, uncorrected richness; white bars, nine haplotypes, corrected richness.