Introduction Pathway Analysis Into New Zealand Highlights a Source Population 'Hotspot' hi the Native Range of the Red Imported Fire Ant (Solenopsis invicta)

摘要

Threats posed by invasive species and the difficulties associated with their control and management places impetus on trying to prevent their spread. Ihe identification of introduction pathways is a vital component towards this goal. We use a geneticmarker-based approach to retrospectively investigate the pathway of origin of the invasive red imported fire ant (Solenopsis invicta Buren) into New Zealand. In addition we determine colony structure by analysing the nuclear locus GP-9. The mitochondrialgene cytochrome oxidase subunit I was sampled, from known incipient nests of S. invicta in New Zealand. A polygyne and a monogyne nest was found. No genetic variation was found within any of the nests, but there was a high level of divergence between the nests suggesting separate incursion events and source populations. We combined both species level and population level genetic analyses in an attempt to identify likely introduction pathways. Our source population approach indicated that was no singleintroduction pathway for this invasive ant in New Zealand that can be specifically targeted by biosecurity authorities. We compared our sequences information to available international studies and found that despite high levels of divergence, geographically the sequences cluster very closely together within their native range. The sequence data suggested that the New Zealand nests ultimately originated in north east and north central Argentine, a finding mirrored in China and possibly the United States.