Twenty years of Argentine ants in New Zealand: past research and future priorities for applied management

Abstract

Abstract The Argentine ant, Linepithema humile (Mayr), is a highly invasive global pest. It has been just over twenty years since Argentine ants were fi rst discovered in New Zealand. Through the result of human-mediated dispersal, they are now relatively widespread, but patchily distributed, in many North Island towns and cities, and also in several locations in the South Island. This review provides a short history of Argentine ant invasion within New Zealand and research conducted to date. It suggests that Argentine ants are still only at the beginning of their invasion in New Zealand, and that estimated treatment costs are set to greatly increase over the next twenty years; but that an opportunity exists to slow the spread of the ants given substantial regional co-ordination. Targeted regional efforts are also needed to protect specific valued sites (e.g. off-shore islands, vulnerable conservation areas). The review identifies knowledge gaps and priority areas which need a timely response as opportunities to restrict the distribution and impact of this species will continue to diminish through the growth of existing populations and increased establishment of new populations. Keywords: Linepithema humile impactscontroldistributiondispersaldetection