Argentine Ants

We can STOP the invasion


The Argentine Ant (Linepithema humile) is one of the world’s most invasive ant species. It is a native of Argentina, but has since become a Tramp species, spreading throughout the world. It was discovered in New Zealand in 1990 and is now present in many urban areas in both the North and South Island.

Argentine ants are very aggressive insects. They will eliminate other species of ants, and also eat or drive away most other insect and invertebrate species. They infest trees and farm huge numbers of aphid, scale and mealy bug. In Auckland, they have been seen devouring baby birds in their nests*, and they will drive nesting birds from their eggs.
Unlike most other ant species, Argentine ant colonies co-operate
with each other and because no time is lost through in fighting, they are able to quickly blanket the area with nests. These nests can then combine over winter into super colonies and cause major problems in buildings *.  Argentine ants also have large numbers of highly mobile Queens, who can invade container plants, loose earth, freight or vehicles.   ANYWHERE WE CAN GO –THEY CAN GO TOO.



Argentine ants are: small brown ants (workers, are only 2-3 mm) so the best way to recognize them is by their trails and their AGGRESSIVENESS.  Argentine ant trails are often five or more ants wide and travel up trees and buildings.   If a nest is disturbed armies of ants will immediately rush out to investigate.  Argentine ants are not poisonous but they do bite and some people are allergic.
Argentine_Ant_Lava Argentine_Ant
  Argentine_Ants_Eating_Moth Closeup_Argentine_Ant



First found in Auckland in 1990 they are becoming widespread through out the Auckland urban area. More recently they have been found in Northland, Waikato, Bay of Plenty, Wellington, Nelson and Christchurch. They have also been discovered on Tiritiri Matangi Island, an important conservation island in the Hauraki Gulf.



Left unchecked, Argentine ants are a major household and garden pest. Their huge numbers (up to 6 nests/sqm) mean huge appetites and they will quickly exploit any food source available.  Foragers have been found in refrigerators, microwaves and even down the glass spiral of a screw-top jar*.  In the Mediterranean where the Argentine ant has been well established for many years, a vast interconnected super colony exists, stretching almost six thousand kms from the north of Italy, through France, Spain and Portugal.  This extraordinary European union of ants contains billions of members.

In New Zealand Argentine ants threaten native invertebrates and many of our native bird species, either attacking them directly or by competing with them for resources like nectar and honeydew.

Argentine ants, like many ant species, ‘farm’ populations of serious plant pests like aphid and scale insects.  Argentine ants protect them from predators and will even move them to new plants.  This causes serious difficulties for Organic growers who rely on biological control of their plant pests.  Argentine ants overseas are considered one of the worst pests of citrus, viticulture, avocado and tomato. We don’t need them in our orchards.



Argentine ants are extremely difficult insects to control. Other forms of treatment like fly spray or boiling water, or the use of REPELLENT chemicals only encourages Argentine ants to ‘bud off’ and create new nests, thus aggravating the situation. This is a bad practice.

However, over the last few years Key Industries has developed and extensively test for NZ conditions a new product ‘X-It Ant’, a weather resistant residual spray, to control and if the whole property is treated, ERADICATE this tenacious pest.

Acting as an outdoor only treatment, X-It Ant becomes rainfast after 1 hour of sunlight and when the ants crawl over the treated surface the fine particle adhere to their bodies. When the ants groom themselves they ingest the poison and they also unwittingly transport minute quantities of the chemical onto their trails to the nests and dislodge the chemical grains inside  the nest.  There the other ants pick it up on their bodies and end up ingesting it when they groom themselves.  Passed around in this way, the X-It Ant efficiently destroys the colony with the minimum of impact on other organisms.  In actual practise, a single application of X-It Ant has shown a dramatic reduction in ant numbers. Subsequent re-treatment of any heavily infested areas can lead to eradication.

Vanquish is an very effective bait in the form of a pale green paste which will control and even eradicate colonies of Argentine ants and some other species of ants. Eradication depends on the whole colony being treated at once.



  • Remove or securely store food
  • Trim trees near the house to stop bridging
  • Reduce moisture sources, e.g. leaking taps
  • Block up obvious entry points
  • Keep waste bins clean
  • Check potted plants when you move them from place to place
  • Check your vehicle regularly, check your camping gear
  • If you have these ants in your area, spray or check plant cuttings before giving them away

Please don’t pack this pest into our precious parks and reserves.

btn_find_out_more.gif about X-It Ant

btn_find_out_more.gif about Vanquish Pro

Contact Us


03 544 4365
16 Gladstone Road
Richmond, Nelson 7020

P.O.Box 3581,
Richmond, Nelson. 7050