Argentine Ant Management in Conservation Areas: Results of a Pilot Study

Abstract. Argentine ants (Linepithema humile) have invaded many areas of conservation concern, including half of the California Channel Islands. On Santa Cruz Island, the species has invaded approximately 2% of the island, and the infestations are expanding. Argentine ants displace many other invertebrates, and their expansion throughout the island could lead to the extirpation of native invertebrate species and the disruption of key ecological processes (e.g., plant-pollinator interactions and seed dispersal). We describe a treatment protocol to manage or eliminate Argentine ants on Santa Cruz Island developed by The Nature Conservancy and the National Park Service, in collaboration with academic and pest control specialists. We combined low-concentration toxicant baits with efficient dispersal methods to treat landscape-scale Argentine ant infestations in rugged terrain and dense vegetation with minimal impact to nontarget species. From May to October 2012, we applied our baiting protocol within 2 study...