This research quantified the internidal (between nest) movements of ants among polygyne red imported fire ant, Solenopsis invicta (Buren), (RIFA) nests. Polygyne RIFA societies have been characterized as supercolonies. This term remains undefined and subject to broad interpretation. Research has shown that there is internidal movement of ants in polygynous RIFA populations. However, to our knowledge, there are no published data quantifying the extent or degree of these internidal movements. We used mass-marking and recapture techniques to investigate ant movement between nests. A total of 53 marked nests were examined. Ants in at least six-neighboring nests were painted a unique color in eight field plots, in east Texas. Forty-eight hours after marking, ants were collected from nests by turning the nests over with a shovel and repeatedly placing a series of collecting sticks inside the disturbed nests for ants to climb onto. The color and number of marked ants collected in each nest were determined in the laboratory under a 10X microscope. We used non-linear regression to determine the proportion of marked workers moving from one nest to neighboring nests as a function of internidal distances. Our results confirmed that there was internidal movement of workers. The distribution of marked workers among nests followed a negative exponential decay curve with increasing internidal distance. Our results show that some polygyne colonies exist as multiple nest (polydomous) colonies, but only at small (< 0.75 m) internidal distances and that interactions among nests are constrained by internidal distances. Certainly these results are not reflective of the over-simplifying term 'supercolony'. In our opinion, polygynous RIFA societies are not comprised of 'supercolonies'. Some may be polydomous at small-scales, but many are found to operate as autonomous colonies, as well.
Species 1: Hymenoptera Formicidae Solenopsis invicta (red imported fire ant)
Keywords: internidal movement
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