Farm Forestry New Zealand
PESTS AND DISEASES OF FORESTRY IN NEW ZEALAND
Red Imported Fire Ant, Whirinaki
RED IMPORTED FIRE ANT – WHIRINAKI
Megan Sarty, from MAF BNZ Report to Forest Biosecurity Consultative Committee, July 31 2008
- On June 7th 2006 Solenopsis invicta (Red Imported Fire Ant) was identified from Pan Pac Forest Products Ltd, Whirinaki. The nest was thoroughly treated with an insecticide drench and insecticidal ant bait on June 9th.
- No further fire ants have been found to date.
- The nest is estimated to be two to three years old and dispersal may have occurred.
- Since the detection the area out to 2km from the nest site has been surveyed three times. Areas that can not be effectively surveyed have been treated with insecticidal ant baits.
- Movement controls have been in place during this time and will remain in place until eradication is declared.
- Surveillance and treatment will be repeated next summer (December 2008 – March 2009). If no further fire ants are found during this time, then eradication will be declared in approximately April/May 2009.
This is the third incursion of red imported fire ants in New Zealand, both previous finds were eradicated. Genetic analysis has confirmed that the Whirinaki colony is unrelated to the previous incursion at Port of Napier in 2004.
Red Imported Fire Ant, Whirinaki
Don Hammond (From NZIF newsletter Number 2007/26 – 6 July 2007)
- On June 7th 2006 Solenopsis invicta (Red Imported Fire Ant – RIFA) was identified from Pan Pac Forest Products Ltd, Whirinaki. The nest was thoroughly treated with an insecticide drench and insecticidal ant bait on June 9th.
- The nest is estimated to be two to three years old and dispersal flights may have occurred.
- This form of RIFA is more likely to disperse by walking short distances rather than flying but is also capable of human-assisted dispersal. We are taking measures through surveillance, movement control and tracing to cover all three possibilities.
- A Controlled Area has been declared out to a 2 km radius from the nest site with restrictions on the movement of all risk goods for RIFA spread including soil, gravel, hay and goods that have been in contact with the ground for more than 24 hours (except operational cars).
- The RIFA Technical Advisory Group was reconvened in September to provide independent advice to the CTO on the proposed plan. This advice formed the basis of the response plan.
- Tracing the movements of high risk items over the past three years has identified a number of high risk sites. The majority of these sites have been surveyed with the balance being surveyed next summer.
- The first round of surveillance out to a 2 km radius from the nest was completed in December 2006, and the second round completed in April 2007. The second round of surveillance will be repeated in each of the next two years.
- Aerial applications of insecticidal ant baits were completed in December 2006 and April 2007. These applications will be repeated in the next two summers.
- No further fire ants have been found to date.
- This is the third detection of a RIFA colony in New Zealand, both previous finds were eradicated. Genetic analysis has confirmed that the Whirinaki colony is unrelated to the previous incursion at Port of Napier in 2004.
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