Assessing landscape-level impacts of red imported fire ants (Solenopsis invicta Buren) on native faunal communities in pine-dominated forests.
Womack, Lee*,1, Hooper-Bui, Linda2, Chamberlain, Michael3, Moser, Barry 4, Landry, Keri 5, 1 Wildlife Ecology, Baton Rouge, Louisiana2 Fire Ant Entomology and Ecology, Baton Rouge, Louisiana3 Mammalian Ecology, Baton Rouge, Louisiana4 Statistician, Baton Rouge, Louisiana5 Department of Wildlife and Fisheries, Pensacoloa, Florida
ABSTRACT- The well-studied impacts of invasive species like red imported fire ants (RIFA) involve disruption and alteration of native communities; yet little research has been conducted on the impacts of RIFA on faunal communities throughout its ever-expanding range in North America. Due to RIFAs high reproductive capacity, aggressive foraging behavior and lack of natural enemies, they have become the dominant ant species in areas they infest. RIFA have become a serious nuisance to humans and have been documented to disrupt mammal, herpetofaunal, invertebrate, and avian communities. We compared Amdro treated and untreated plots in two forest ecosystems to test the effects of fire ants on native small mammal, herpetofauna, and invertebrate communities. This two year study, found that Amdro was effective in suppressing RIFA in a longleaf-pine savanna (P = 0.0003) and a mixed pine-hardwood site (P < 0.0001). Invertebrate communities in the treated and untreated mixed pine-hardwood plots showed no significant difference at the ordinal level (P > 0.05); but we found a significant difference in Acaria and Diptera in the longleaf-pine ecosystem (P = 0.0165 and 0.0171 respectively). Small mammal communities were sampled using mark and recapture; the mixed pine-hardwood site showed a 7% increase in recaptures on treated plots and a 32% decrease on untreated plots; while the longleaf-pine savanna showed a post-treatment increase of 19% recaptures on treated plots and a 16% increase on untreated plots. These data suggest RIFA may pose little effect to invertebrates at the ordinal level, but may affect other faunal taxa such as small mammals depending on habitat type.
Key words: Fire Ants, Amdro, Small Mammals, Invertebrates
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