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While invasive species eradications are at the forefront of biodiversity conservation, ant eradication failures are common. We reviewed ant eradications worldwide to assess the practice and identify knowledge gaps and challenges. We documented 316 eradication campaigns targeting 11 species, with most occurring in Australia covering small areas (b10 ha). Yellow crazy ant was targeted most frequently, while the bigheaded ant has been eradicated most often. Of the eradications with known outcomes, 144 campaigns were successful, totaling approximately 9500 ha, of which 8300 ha were from a single campaign that has since been partially re-invaded. Three active ingredients, often in combination, are most commonly used: fipronil, hydramethylnon, and juvenile hormone mimics. Active ingredient, bait, and method varied considerablywith respect to species targeted,which made assessing factors of eradication success challenging. We did, however, detect effects by active ingredient, number of treatments, and method on eradication success. Implementation costs increased with treatment area, and median costs were high compared to invasive mammal eradications. Ant eradications are in a phase of increased research and development, and a logical next step for practitioners is to develop best practices. A number of research themes that seek to integrate natural history with eradication strategies and methodologies would improve the ability to eradicate ants: increasing natural history and taxonomic knowledge, increasing the efficacy of active ingredients and baits, minimizing and mitigating non-target risks, developing better tools to declare eradication success, and developing alternative eradication methodologies. Invasive ant eradications are rapidly increasing in both size and frequency, and we envisage that eradicating invasive ants will increase in focus in coming decades given the increasing dispersal and subsequent impacts.

Merremia peltata, disturbance ecology, tropical cyclones and Samoa. The biology and ecology of Merremia peltata are not well understood. While some regard the species as an exotic invader of Pacific Island ecosystems (Meyer. 2000). others identify the plant as a native species likely to be harmful to native ecosystems (Whistler, 1995a. 2002) or as either native or ancient Polynesian introduction behaving invasively (Space and Flynn.(2002). In Samoa, this species occurs up to an elevation of around 300 meters (Whistler 1995a). and thus only affects lowland ecosystems. This species increases its distribution and abundance in two ways, either vegetatively. by sprawling into neighboring areas and rooting from its nodes or by seeds, although early research in the Solomons observed a low seed viability rate, and creeping may thus be its primary means of reproduction (Bacon. 1982). M. peltata has apparently been in the Pacific for hundreds of years (Whistler, pers. com.) but has only become invasive in the years following tropical cyclones Ofa (1990) and Val (1991) according to comments from local government officials. Disturbance thus appears to be an ecological contributing factor to this invasion.