The European fire ant (Hymenoptera: Formicidae) as an invasive species: impact on local ant species and other epigaeic arthropods

Pitfall trapping revealed that the European fire ant,Myrmica rubra(Linnaeus) (Hymenoptera: Formicidae), represents an unusual example of a temperate invasive ant species. In British Columbia, Canada,M. rubrapopulations are associated with a decreased incidence and abundance of other ant species in three different plant communities when compared withM. rubra-free control areas.M. rubrarepresented more than 99.99% of the total ant fauna caught in the infested areas, and the numbers ofM. rubracaptured in the plant communities ranged from over 10 times to over 1300 times the total number of all ants collected in correspondingM. rubra-free areas. Total numbers of some taxa of insects and non-insect arthropods, including those likely to be competitors or prey ofM. rubra, were reduced where the invasive species was present. Biodiversity indexes for the overall suite of captured arthropod species were lower whereM. rubrawas present in all three plant communities but most of this decrease can be attributed to the difference in the ant fauna.