Red Imported Fire Ant

Solenopsis invicta

Red Imported Fire Ant

Red Imported Fire Ant

Legal Status: Unwanted Organism - BNZ
Status in New Zealand: Eradicated
Organism: Insects, worms and other land invertebrates


Red imported fire ants are reddish brown in colour, although some have a shiny opaque black abdomen. Size varies from 3-6 mm in length.


Native to South America, red imported fire ants are capable of spreading across wide areas and pose a direct threat to human health and lifestyles, as well as our native flora and fauna. The ants are effective foragers and they are aggressive. If disturbed, they will sting to defend their nest and surrounding area, and the stings can be painful for both humans and animals.

Red imported fire ants also cause damage to agricultural equipment, roads and electrical equipment due to size and location of nest mounds.

Incursions in New Zealand

There have been three incursions of this ant since 2001. The first two incursions were in border control areas, Auckland International Airport in March 2001 and Napier Seaport in 2004. The most recent incursion of this ant occurred in Whirinaki, North of Napier where a nest was discovered on 9 June 2006. MAF Biosecurity Zealand responded with a three year eradication programme and recently declared red imported fire ants eradicated from Whirinaki, Napier on 22 April 2009.

All movement controls that were implemented on 23 June 2006 to prevent the inadvertent spread of any remaining fire ant colonies on contaminated material have been lifted, effective 4 pm, 22 April 2009.

MAF Biosecurity would like to acknowledge the support and cooperation from residents and businesses in the Whirinaki area in complying with the movement restrictions for three years.


MAF Biosecurity New Zealand commissioned three research projects in 2008/9 to address key information gaps associated with red imported fire ant incursions. The three research projects incorporate two literature reviews and a food preference and foraging distance study to determine the sensitivity of current fire ant surveillance in New Zealand. A model of the probability of detecting red imported fire ants was developed as part of the research project.

Literature reviews

Research Project


Release Assessment Link to PDF document (1211 KB)
Fact Sheet (offsite link to

If you suspect you have found red imported fire ants call MPI exotic pest and disease hotline on 0800 80 99 66

Page last updated: 11 February 2015