You will find Argentine ants mostly in southern United States and in
California.
The general consensus is that they may have entered the United States
aboard ships carrying coffee or sugar from Argentina during the 1890s, then
expanded throughout California and the southern parts of the United States.
Because the fire ant is such a strong competitor to the Argentine ant they
are not as populated in the south east part of the United States
These types of natural competitors are largely absent in California and this state has seen them thrive in the temperate and damp coastal regions. They have killed and displaced native ants, many of which are ten times larger in size.
Click on image to enlarge
Image courtesy of :
ucsdnews.ucsd.edu
You won't find winged forms because mating usually is found in
the nest. Argentine ants are aggressive, often eliminating other types of ants
in the same area.
They also destroy and eat other household pests such as cockroaches and exposed termites.
However, they prefer sweets and are often found tending aphids or scale
insects on plants, using them as source of honey dew.
They usual habitation is outside, but can present a problem
when they come inside foraging for food.
They rarely nest in walls of buildings, as the pharaoh ant.
They more often than not, enter to forage and then exit.
Argentine Ant Apperance
The wingless worker ant(most commonly spotted),
is light to dark brown, about 1/12
to 1/8 inch long .
The antennae are strongly elbowed(12 segments) and there is a single node
in front of the abdomen(a waist).
Queens are 1/6 to 1/4 inch long.
How to Identify Argentine Ants:
- Uniformly dull brown
- Petiole with 1 erect node
- Thorax uneven in shape when viewed from side
- Musty odor emitted when crushed
- When identifying Argentine ants, be sure to look for the uneven thorax and 1 erect petiole node.
Photo and ID text courtesy of
UC IPM Online
Argentine Ants Life Cycle
The
winged queens can produce fertile eggs for up to 10 years after mating once
with a winged male. Another difference in this type of ant compared to other
ants, is that several productive queens can share the same colony.
One or more of these Argentine productive queens may leave with some of the
workers to form a new colony when it gets crowded (this is known as "budding").
The grub like larvae are fed and tended by the workers, pupate, then emerge
to join their sisters in the colony (worker ants are all sterile females).
The eggs are white,laid in summer;larvae emerge after about 28 days.
The larval stage may be completed in from 11-60 days.
The pup al period may go to over 10-25 days.
Development from egg to adult usually takes about two months,
but it may be 4-5 months.
During the summer months,satellite nests are usually established close
to food sources and these satellite nests are highly mobile.
Ant Trails
An excellent article by
Univ. of Florida Extension Service can be found at
Ant Trails:Baiting.
It gives an overview of management with baits.
How to Get Rid of Argentine Ants
Baiting would be the preferred treatment over
typical residual spraying,
so you can eliminate the entire colony, unless you use a non repellent spray.
When choosing ant baits, it is best to choose from both the sugar based baits and protein based baits .
Why Ant Bait ?
The use of residual
sprays or dusts will cause stress on the colonies,
causing them to split
into sub-colonies that scatter to other areas in the structure.
This is also called budding.
After spraying, your problem can be worse than at the beginning.
When you bait, you will want a slow acting bait.
Quick kill insecticides and baits will only kill the foraging ants,
not allowing the foraging ants to take the bait back home to feed the queen,
nest workers and brood.
If the current ant bait that you are using is not acceptable to the ants,
if they are not visiting the bait,
it is recommended that you change the baits.
They find a variety of these sources in nature.
Examples are: other insects(proteins and greases), nectar, aphid honeydew
, plant products(sugar and carbohydrates)
Choosing a bait would require knowing what they are currently feeding
off of,
according to the nutritional needs of the colony.
To be sure that you have all the baiting needs met,
you may want to be ready with a sugar-carbohydrate bait,
a grease-fat bait, and a protein based bait.
IT IS VERY IMPORTANT TO REMOVE ANY OTHER FOOD COMPETITION WHEN BAITING
AND LEAVE THE BAIT ALONE ONCE THE ANTS START FEEDING ON IT.
Argentine Ant Habits
Argentine ants can persist in conditions where
other ant species could not
survive.
They like to nest in moist soil next to buildings or under them.
They
can be found near sidewalks or plants.
They nest near water and food sources.
Foraging ants will enter the house when outside conditions
are extremely dry
or wet.
Colonies are large, often containing hundreds of queens.
The queens and larvae form will eat the protein / grease combination
almost exclusively,
while the workers will eat
the sugar based baits.
They are extremely mobile, will move colonies frequently.
Argentine ants generate strong pheromone trails when foraging. They can
be easily tracked. In many areas, you will see them patching three and four
abreast.
Diet
Argentine ants prefer sweet foods such as syrup, fruit juices or plant
secretions as well as protein. They gather food day and night.
The workers will only eat the sugar.
Of all the smaller sized ant,
this one prefers sweet more than protein.
Non Repellents For Outside and Inside Ant Control:
Spraying for Argentine Ants: Non-Repellents
The best insecticides for ant control are non repellent insecticides such as Taurus SC, Termidor SC, Optigard Flex, Alpine Aerosol, and Phantom Aerosol. Termidor SC and Taurus SC are labeled for inside usage.
Unless you can treat the nest directly, spraying
is not an effective solution for Argentine Ants, unless you use
a non repellent insecticides or "undetectable" liquid treatments
Phantom Aerosol or Alpine Aerosols labeled for the inside. Optigard Flex is another very good non repellent labeled for inside for Argentine Ants(ants popular in California)
Unlike older insecticides,
non repellent insecticides can't be smelled, tasted, or even
felt by pests. So they crawl through the treated area, not
knowing that by ingesting treated materials or merely contacting
the insecticide, they'll die.
Again, workers must eat the bait, take it back to the nest, and feed to the queen and larval ants. This type of control is incompatible with treatments(such as repellent sprays)that prevent workers from returning to the nest with the bait.
