Invasion of four argentine ant supercolonies into kobe port, Japan : Their distributions and effects on indigenous ants (Hymenoptera: Formicidae)

Abstract

The presence and distribution of four antagonistic Argentine ant supercolonies within closed areas in Kobe Port, Hyogo Prefecture, Japan, were revealed. Three of them had already caused severe reduction of ant species richness, whereas one coexisted with many indigenous ant species. We detected two contact zones of Argentine ant supercolonies, where indigenous ants occurred. Studies in these contact zones would provide insight into the hypothesis that lack of intraspecific aggression is responsible for the displacement of indigenous ant s by Argentine ants, although the competitive ability of one supercolony described above must be carefully examined.