How hitchhiking by fire ants, Solenopsis invicta (Hymenoptera: Formicidae), challenges efforts for their eradication in Australia

Abstract

The ability of the red imported fire ant, Solenopsis invicta Buren, to spread naturally by flight or by budding from existing colonies, as well as via transport of infested goods and materials, makes containing and eradicating this species particularly challenging. In Australia, a national Program for the eradication of S. invicta has been in operation since its first discovery in Queensland’s capital city, Brisbane, in 2001. Since that time, 8 of the 9 known incursions of S. invicta into Australia have been successfully eradicated, but the main Brisbane population persists and now covers more than 830,000 hectares in urban and rural areas. As the infestation footprint has expanded, encompassing an increasing number and variety of business activities, so too has the difficulty of devising and instituting effective movement controls on products that may harbor the ant. Here, we discuss the risks and challenges posed by some of these products along with examples of dispersal events that have occurred over the life of the Program. Knowledge of S. invicta’s biology and behavior is key to the development of effective risk mitigation strategies.