Preparing to eradicate a novel invader of unknown biology: a case study from Australia

Abstract

Although there have been many attempts at eradicating exotic ant incursions, most efforts have been unsuccessful, and a lack of specific biological knowledge is believed to have been a major contributing factor. In early May 2013, an exotic ant species, Lepisiota frauenfeldi , was found for the first time in Australia. Identifying the species proved difficult, and little biological information about the species was available. In making the decision to eradicate and develop the treatment protocols, four assumptions were made about the ant’s biology. Here we detail rapid and basic research that was used to assess the assumptions underpinning the decision to eradicate, contribute to determine some eradication protocols for this understudied species, as well as how our understanding increased following the discovery of two other incursions of this species in Australia. The research found that all initial assumptions of the ant’s biology used in the original eradication plan were wrong. Distribution modelling found the ant could potentially inhabit a larger area than first thought, and updating the model with the subsequent incursions greatly increased the area of suitable climate in Australia. The ant’s foraging and reproductive regimes were not as expected, so too its nutrition pathways to queens, which had implications for the treatments. Our work serves as a clear warning for invasive species practitioners that management decisions that are based on assumptions, “gut feelings” or knowledge based on information from elsewhere in the world, or from other species, can be expected to be flawed. Rapid, small-scale and strategic research conducted on-site can enhance management outcomes.