ANT CONTROL
Invasive Ants
Two of the major pest species that have been introduced to New Zealand are Darwin's Ant and the Argentine Ant.
Darwin Ants
Darwin Ants are small (2-3mm) brown ants that have become established in Christchurch and other parts of the country as a pest of our homes, shops and other buildings. Its distribution is rapidly expanding and it may form 'super' colonies where many nests are part of the same colony and workers from one nest can move to another. Darwin's Ant came to NZ from Darwin in Australia and has found the environment in NZ to its liking. In NZ it forms much larger colonies than in it's native Australia. It can be distinguished from a similar looking Argentinean Ant by its pungent smell when squashed.
Argentine Ants
Argentine Ants are an even more recently invasive species to Christchurch and have been found by Target Pest in several locations around the city. It is a much more common pest in the North Island of New Zealand. Target Pest has recently (2007) successfully carried out a major control operation in Northland for the District Council and local residents.
Argentine Ant nests should not be treated with insecticide as this may only serve to disperse colonies and spread infestation. A specialized bait developed by LandCare Research is the preferred option for control of these ants. Target Pest has access to this bait and works closely with Landcare Research to develop the methodologies of its use.
If you find small brown ants please call TARGET PEST on 0800 487 277 for identification and advice. The Yellow Crazy Ant, Crazy Ant and Red Imported Fire Ants are a quarantine threat to New Zealand and Target pest will carry out free identification of any ants found.
Other Ant Pests
There
are over 30 species of ants in New Zealand and more than 20
of these species are introduced. Many invade homes and other
buildings in search of food, warmth and shelter. These include Darwin ant, Argentine ant and White footed house ant.
Ants often
nest in sandy soil, in the foundations of houses or under
paving. Here they usually cause little harm. Problems occur
when the ants nest within a building or enter buildings foraging
for food or climb onto your barbecue, becoming a nuisance
and contaminating food. Ants will often form trails from the
food source to the entrance of their nest. The food of ants
can include both sweet and savoury foods depending on species
and time of year. For most species, colonies begin when a
single winged female lays her eggs. She will tend and feed
the larvae that emerge for approx. 8-9 weeks. When the adult
ants emerge they become workers for the new Queen. These workers
will tend the Queen and subsequent larvae, as well as foraging
for food. Food sources may include nectar from flowers, dead
insects, sweet secretions from green fly or your jam sandwich.
Mating usually takes place in late summer when males and large
females take wing; they can form large swarms, which usually
last for 2-3 hours. All males die, leaving mated females to
found new colonies.
A list of the more common species and some details
of their biology can be found on the Landcare Research ants web
site.
Control Methods
Identification
is vitally important to control ants,
as the methods must be tailored to the ant species involved.
Incorrect control methods may only serve to exacerbate the
problem as in spraying an Argentinean ant colony with insecticide.
Because of the hidden locations of nests, ants
can be difficult to control. Nests can often be located outside,
under slabs, tarmac or concrete, with little or no evidence
of their presence. The entrance to a nest can be established
by leaving some fine breadcrumbs where you see ants. One can
then follow the ants as they carry the crumbs back to their
nest. Treatment at the entrance alone is rarely successful
and treatment of a nest site may encourage multi-queened colonies
to disperse and spread infestation to surrounding sites as
in Argentinean Ants.
TARGET PEST always uses a combination of baiting,
spraying, barriers and proofing to control ant colonies.
Contact our Office for advice. Toll free on 0800 487 277
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