Enzyme polymorphisms in the fire ant,Solenopsis invicta (hymenoptera: formicidae)

A survey of allozyme variability in the fire ant, Solenopsis invicta Buren, was conducted using samples collected throughout the species' range in North America. A substantial amount of variability was found, although heterozygosity estimates were considerably less than estimates for diploid non-hymenopterous species. The presence of this variability raises the possibility of multiple introductions of this ant to North America. Although based on a limited sample, our data indicate no differences in variability between individuals from monogynous and polygynous populations or between individuals from the Mobile, Alabama area (presumed point of introduction) and outside the area. Individuals from polygynous colonies shared all detected alleles with individuals from monogynous colonies indicating the lack of long-term reproductive isolation between the two types of populations.