Impacts of an incursion of African Big-headed ants, Pheidole megacephala (Fabricius), in urban bushland in Perth, Western Australia
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An incursion of the African Big-headed Ant, Pheidole megacephala, has recently been recorded in bushland in Perth, Western Australia. This unexpected discovery prompted an investigation into the effects of the incursion on the native ant assemblages. Extensive pitfall trapping in invaded and non-invaded areas revealed that the incursion had a significant negative impact on ant species richness, diversity and evenness. Approximately 53% of native ant species present in non-invaded bushland were not sampled in areas occupied by P. megacephala, while the remaining species suffered considerable declines in frequency of occurrence. Many of these species perform important ecosystem functions, and their loss was thought to have had serious consequences on the ecosystem. Changes to the prevalence of the various ant Functional Groups indicated major disruptions to the composition of the assemblage as the abundance of P. megacephala increased. Ants that avoided direct competition with P. megacephala, by occupying temperature dependant temporal niches, were more persistent in its presence. Estimates of the ant biomass sampled indicated that the invasive population was larger than that of all other ant species combined by several orders of magnitude. A feeding trial revealed intensified exploitation of food resources in invaded areas, which could have flow-on effects on other invertebrates and plants. Changes to predation, decomposition, and soil amelioration regimes, as well as possible disruptions to ant-plant interactions and invertebrate symbioses resulting from the disappearance of native ant species, were thought to have further eroded the conservation values of the ecosystem.
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Impacts of an incursion of African Big-headed Ants, Pheidole megacephala (Fabricius), in urban bushland in Perth, Western AustraliaCallan, Shea; Majer, Jonathan (2009)An incursion of the African Big-headed Ant, Pheidole megacephala, has recently been recorded in bushland in Perth, Western Australia. This unexpected discovery prompted an investigation into the effects of the incursion ...
Majer, Jonathan; Gove, Aaron; Sochacki, S.; Searle, P.; Portlock, C. (2011)Members of the genus Rhytidoponera and, to a lesser extent, certain Melophorus spp. are keystone mutualists for the dispersal of seeds in the southwest of Western Australia, with important ramifications for the ecology ...
Abiotic factors affecting the foraging activity and potential displacement of native ants by the invasive African big-headed ant Pheidole megacephala (FABRICIUS, 1793) (Hymenoptera: Formicidae)Asfiya, W.; Yeeles, P.; Lach, L.; Majer, Jonathan; Heterick, Brian E.; Didham, R. (2016)The African big-headed ant Pheidole megacephala is an invasive non-native species that threatens native ecosystems throughout many regions of world. As it spreads into new areas, P. megacephala becomes abundant and reduces ...