Modelling the potential spread of Solenopsis invicta Buren (Hymenoptera: Formicidae) (red imported fire ant) in Australia

Abstract

Quantifying the potential spread and density of an invading organism enables decision-makers to determine the most appropriate response to incursions. We present two linked models that estimate the spread of Solenopsis invicta Buren (red imported fire ant) in Australia based on limited data gathered after its discovery in Brisbane in 2001. A stochastic cellular automaton determines spread within a location (100 km by 100 km) and this is coupled with a model that simulates human-mediated movement of S. invicta to new locations. In the absence of any control measures, the models predict that S. invicta could cover 763 000-4 066 000 km 2 by the year 2035 and be found at 200 separate locations around Australia by 2017-2027, depending on the rate of spread. These estimated rates of expansion (assuming no control efforts were in place) are higher than those experienced in the USA in the 1940s during the early invasion phases in that country. Active control efforts and quarantine controls in the USA (including a concerted eradication attempt in the 1960s) may have slowed spread. Further, milder winters, the presence of the polygynous social form, increased trade and human mobility in Australia in 2000s compared with the USA in 1940s could contribute to faster range expansion.

Invasive ants in Australia: documented and potential ecological consequences

“…Almost all coastal areas are predicted to be climatically suitable for more than one species (Commonwealth of Australia 2006). The red imported fire ant could cover over 2 000 000 km 2 within Australia by 2028 if no longterm control measures are in place (Scanlan & Vanderwoude 2006). Ever increasing domestic and international travel and trade will facilitate further introductions and dispersal of new species and species that are already present.…”

Biodiversity of Australasian Insects

“…The species had probably been present undetected for several years already, stemming from two separate breaches of quarantine (Henshaw et al 2005). With predictions of rapid spread across the continent (Scanlan and Vanderwoude 2006), a massive plan to eradicate the species was quickly put in place as the state (Queensland) and federal governments recognized and listed the presence of the red imported fire ant as a key threatening process to biodiversity. Through intensive baiting with methoprene and piriproxyfen, coupled with a massive public awareness campaign, a 99% reduction had been attained by 2004.…”

Future ant invasions in France

“…One group of invasive species that is of particular concern for conservation are ants (Holway et al 2002;Rabitsch 2011); because of their small size, they are easily transported by accident, in particular on fruits or on ornamental plants. Invasive ants have a tremendous impact on local biodiversity (Lach & Hooper-Bui 2010), ecosystem functioning (Holway et al 2002), economics (Harris & Barker 2007), and even human and domestic animal health (Moreira et al 2005;Scanlan & Vanderwoude 2006). Once established, invasive ants become very difficult to eradicate (Hoffmann et al 2010).…”