| Summary: | Within ant communities, the biotic resistance of native species against invasive ones is expected to be rare, because invasive species are often highly dominant competitors. The invasive Argentine ant (<i>Linepithema humile </i>(Mayr)) often demonstrated numerical dominance against its opponents, increased aggressiveness, and ability to quickly recruit to food. The present study aimed to assess the behavioral mechanisms involved in the interspecific competition between <i>L. humile</i>, facing either an invasive species (<i>Lasius neglectus </i>Van Loon, Boomsma and Andrásfalvy) or a native dominant species (<i>Lasius niger </i>(Linnaeus)). The resource exploitation by the Argentine ant was investigated during one-hour competitive interactions using 10 dead <i>Drosophila</i> flies as prey. When facing <i>La. niger</i>, <i>L. humile</i> exploratory behavior was strongly inhibited, it brought very few prey resources, and killed few opponents. Conversely, <i>La. neglectus</i> had a low impact on <i>L. humile</i>. Contrarily to expectations, the invasive <i>La. neglectus</i> lacked the ability to hinder <i>L. humile</i> resource exploitation, whereas the native <i>La. niger</i> did. These results suggest that <i>La. niger</i> could impact invasive populations of <i>L. humile</i> by interference competition, perhaps better so than some invasive species. While <i>L. humile</i> has become invasive in Southern Europe, the invasion process could be slowed down in the northern latitudes by such native dominant species.
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