Response of an open‐forest ant community to invasion by the introduced ant, Pheidole megacephala

Abstract

The introduced tramp ant, Pheidole megacephala, is a well‐known pest of urban areas and coastal dune ecosystems in eastern Australia. Until recently, establishment and spread of P. megacephala colonies has been regarded as likely only in disturbed areas. Here we describe the extent of an established colony of P. megacephala in a long undisturbed open forest near Maryborough in southeast Queensland and compare ant community structure with those of nearby uninfested sites. Tuna baiting revealed three distinct zones: (i) a zone totally dominated by P. megacephala (at least 10 ha) where few other ant ant species were detected; (ii) a zone where P. megacephala was absent and many other ant species were found; and (iii) a zone where opportunists (species of Ochetellus and Paratrechina) competed with P. megacephala at baits. Pitfall trapping over a 9‐month period resulted in 12 species being recorded at the infested site, compared with a mean of 25 species recorded at adjoining uninfested forest. Over 94% of ants recorded in pitfalls at the infested site were P. megacephala. Most notably, P. megacephala had completely displaced dominant Dolichoderines (species of Iridomyrmex), subordinate Camponotini (species of Camponotus, Opisthopsis and Polyrhachis) and other species of Pheidole which are common at forest sites.

Diversidade e riqueza de formigas (Hymenoptera: Formicidae) em remanescentes de Mata Atlântica na Bacia Hidrográfica do Alto Tietê, SP

“…Determinadas espécies especialistas nidificam nesses locais, como é o caso de Typhlomyrmex rogenhoferi (Lacau et al 2004, Delabie et al 2007) registrada na serapilheira das áreas de Floresta Ombrófila Densa da Barragem de Biritiba Mirim e do Parque Estadual Nascentes do (Nafus 1993, Harris & Barker 2007, Vanderwoude et al 2000, Hoffmann 2010). Essas espécies exóticas são frequentes nas áreas urbanas das cidades do Alto Tietê (Kamura et al 2007, Munhae et al 2009.…”

Introduced Pheidole of the world: taxonomy, biology and distribution

“…As in several other invasive ant species, colonies are polygynous, and dependently founded via budding, with nests in large areas often forming supercolonies (Hoffmann 1998) that aggressively fight other ants or outcompete them by depleting their prey and other resources (Dejean et al 2008; Fournier et al 2009; Hoffmann et al 1999; Vanderwoude et al 2000). …”

Resource competition assays between the African big‐headed ant, Pheidole megacephala (Fabricius) and the invasive Argentine ant, Linepithema humile (Mayr): mechanisms of inter‐specific displacement

“…Both L. humile and P. megacephala were able to rapidly discover, recruit to a resource with high intensity, and retrieve a large amount of food with equal prowess in the absence of a competitor. Although this is a globally known fact for Argentine ants (Human & Gordon, , ; Davidson, ; Holway et al, ), evidence to support these characteristics for P. megacephala has not empirically been tested previously but rather inferred from the predictable foraging behaviour exhibited by most invasive ant species and the fact that P. megacephala are populous where they are introduced (Majer & de Kock, ; Hoffmann et al, ; Vanderwoude et al, ; Dejean et al, ).…”