Species discrimination and population differentiation in ants using microsatellites

This study was conducted to establish the regional scale of population differentiation of ants in the wheat belt of central western New South Wales. Microsatellite variation was surveyed at five loci in two morphologically similar ant species (designated “A” and “B”) from the Camponotus ephippium complex. Three of the five scored microsatellite loci were highly variable with totals, in the two species, of 11, 13 and 42 alleles. The other loci had two and three alleles. The mean number of alleles per locus per sample ranged from 2.0 to 4.6 for species A and from 1.4 to 3.8 in species B. Mean observed heterozygosity was 0.385 for species A and 0.363 for species B. The geographic distribution of genotypes was significantly non-random for all tested loci in both species. Eight of 47 alleles in species A and 15 of 28 in species B were restricted to a single site. Allelic accumulation percentages were calculated for several orderings of samples — level of heterozygosity, sample size and geographic position. In all orderings three or more samples must be included for more than three-quarters of alleles to be represented.