To kill invasive ants, feed them what they want

To kill invasive ants, feed them what they want

Argentine ants attack a fipronil-treated termite prey. Lab and field tests show that prey-baiting is an effective method for controlling invasive ants and requires far less insecticides than traditional control methods. (Credit: John Obermeyer/Purdue)

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Poison bait is meant to smell and taste like foods that pest insects like invasive ants like to eat. But giving them the real thing instead of a knockoff might be a better option, researchers report.

When researchers coated termites with poison and set them free near colonies of invasive ants in South Africa, nearly every ant died within three weeks—using far less insecticide than traditional control methods.

“All ants eat protein to grow, and they usually get it by preying on insects,” says Grzegorz Buczkowski, a research associate professor of entomology at Purdue University. “We are feeding them what they want and getting better results.”

There are invasive ant species on nearly every continent, often brought from their native countries to others in the holds of ships. The Argentine ant, for example, came from Argentina to the United States more than a century ago in soil used as ballast on ships. When the ships arrived in Louisiana, they dumped the soil to load up on cargo, and the ants started to spread, reaching much of the southern portion of the country.

Argentine ants outcompete many other species, disrupting ecological interactions and also consume secretions from crop pests, such as aphids. In return, they protect those pests from natural predators, allowing their populations to grow.

“Argentine ants are highly aggressive and competitive. It’s why they can outcompete native ants. But that works against them”

It’s the Argentine ants’ ability to dominate other species that makes the new control method so effective.

“Argentine ants are highly aggressive and competitive. It’s why they can outcompete native ants,” Buczkowski says. “But that works against them. When you put out termites, Argentine ants are the first to find them. They take these termites back to the nest and poison the whole colony.”

In field tests in South Africa, Buczkowski created six 100-square-meter plots and released termites coated in fipronil, a broad-spectrum insecticide. In four plots, the insecticide eradicated 100 percent of ants within 21 days. In the other two, the insecticide killed nearly 98 percent of the ants.

Fipronil is often used in other forms, but those require far more of the poison to control the same area. It would take 2,644 times more liquid spray, and 16,158 times more granules to cover 100 square meters. Those forms must be spread on the ground, and can also kill insects not meant to consume the poisons.

The termites have another advantage over other forms of poisons. Granules, gels, and sprays only affect the worker ants that come into contact with or consume them.

Hydrogel bait lures ants to a killing party

But the worker ants can’t digest termites themselves. Instead, they use a process called trophallaxis. They take the termites back to their nests and feed them to larvae, which pre-digest the insect and feed it back to the workers. The predigested termites poison the larvae, the workers, and the queens who receive the food from workers.

“With some baits you kill off the workers, but you still have queens and broods, and a few weeks later you have a new generation,” Buczkowski says. “With this, you’re stopping the colony from reproducing.”

While the termites die within an hour of researchers painting them with fipronil, Buczkowski isn’t recommending setting termites loose near homes or other buildings to control ant populations. Instead, he sees the method as an effective way to control invasive ant populations in large natural areas that contain colonies with millions of ants.

Future research will include testing other poisons, as well as different bait insects and other species of invasive ants. Since ants tend to want fresh prey, researchers are also experimenting with freeze-dried termites that look fresh but could be pre-treated and taken to field areas to kill ants.

The researchers report their findings in the Journal of Applied Entomology.

Argentine Ants

Where Argentine Ants Are Found

You will find Argentine Ants mostly in the southern United States, especially California. It is generally understood that Argentine Ants may have entered the United States aboard ships carrying coffee or sugar from Argentina during the 1890s. They expanded from the coast throughout California and to the southern parts of the United States. Argentine Ants find Fire Ants to be fierce competitors, and so Argentine Ant populations are not as numerous in the southeastern parts of the United States.

Since Fire Ants and other competitors are largely absent in California, this state has seen the Argentine Ant thrive in the temperate and damp coastal regions. Argentine Ants have killed and displaced native Ants, many of which are ten times larger in size. Argentine ants are megacolony ants with an enormous capacity for growth and expansion due to their many queens and splintering off to new colonies.

You probably won’t ever see a winged form of the Argentine Ant, because mating is usually accomplished in the nest, not in mating flights. 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.Their usual habitation is outside, but these ants can present a problem when they come inside foraging for food. They rarely nest in walls of buildings, as some other ants commonly do. They enter to forage and then exit, returning to the nest.

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Their usual habitation is outside, but these ants can present a problem when they come inside foraging for food. They rarely nest in walls of buildings, as some other ants commonly do. They enter to forage and then exit, returning to the nest.

Argentine Ant Appearance

  • Here are some things to look for when identifying Argentine Ants:
  • The wingless worker Ant (most commonly spotted), is light to dark brown, about 1/12–1/8-inch long.
  • The antennae are strongly elbowed (12 segments) and there is a single node in front of the abdomen (the waist).
  • Queens are 1/6–1/4-inch long.
  • Uniformly dull brown color
  • Petiole (the node that separates the thorax from the abdomen) has one erect node
  • Thorax (middle part supporting the legs) is uneven in shape when viewed from the side
  • Musty odor emitted when Ant is crushed
  • Photo and ID text courtesy of UC IPM Online

Argentine Ant 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 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, and then emerge to join their sisters in the colony (worker Ants are all sterile females). The white eggs are laid in the summer, and the larvae emerge after about 28 days. The larval stage may take from 11–60 days. The pupal period may last from 10–25 days or more. Development from egg to adult usually takes about two months, but may take up to 4–5 months. During the summer months, highly mobile satellite nests are usually established close to food sources.

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 (mega colonies),often containing hundreds of queens. The queens and larvae eat protein/grease foods (and baits) almost exclusively, while the workers eat sugar-based foods (and baits).
  • Most ants establish new nests by swarming to mate. These ants mate inside the nest from reproductives produced inside the nest.
  • They are extremely mobile and will relocate colonies frequently. They will establish new colonies many times because of many external factors such as food sources, changing temperature, and proximity to woody plants. Argentine Ants can be easily tracked because they generate strong pheromone trails when foraging. In many areas, you will see pheromone trail super-highways three and four lanes wide.

Argentine Ant Diet

Argentine Ants prefer sweet foods and are often found tending aphids or scale insects on plants, using them as a source of honeydew. Argentine Ant workers like sweet foods such as syrup, fruit juices or plant secretions, but will gather protein/grease-based foods to bring back to the queens and larvae. They gather food day and night. Of all the smaller sized ants, this one prefers sweet more than protein.

Argentine Ant Control

Unless you use a non-repellent spray, baiting is the preferred treatment over typical residual spraying. Baiting is the most reliable way to eliminate the entire colony. When choosing ant baits, it is best to choose from both the sugar-based baits and protein/grease-based baits. If using a spray, choose a non-repellent type unless you are treating the nest itself.

Argentine Ant Control Using Ant Bait

  1. The use of residual sprays or dusts stress ant colonies, causing them to split into sub-colonies and scatter. This scattering, also called budding, multiplies the number of ant colonies, and thereby multiplies your ant problem.
  2. When you bait, use a slow-acting bait. Quick-kill insecticides and baits will only kill the foraging ants, not allowing those worker ants to take the bait back home to feed the queen, nest workers, and brood.
  3. If the ant bait that you are currently using is not effective (if the ants are not visiting the bait) you will need to change the baits. Slow-acting baits provide a variety of the foods the ants find in nature. Examples are: other insects (proteins/grease-based baits), nectar, aphid honeydew, and plant products (sugar and carbohydrates found in sweet-based baits).
  4. Choosing a bait requires an understanding of 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-based bait, a grease/fat-based bait, and a protein-based bait.

An excellent article by the University of Florida Extension Service can be found at Ant Trails: Baiting. It gives an overview of management with baits.

Recommended Argentine Ant Baits (Sweet and Protein/Grease Feeding Cycles)

When in doubt of which one to choose, choose one from each category.

  • Top recommendation from the protein/grease category is Invict Blitz orInvict Xpress (Invict Blitz can only be sold in FL, GA,. LA and TX)
  • To recommendation from the sweet feeding category is Optigard Ant Bait Gel

The Mega-Colony Ant Kit has Advion Ant Gel, Invict Xpress and Dominion 2L combined as a kit, saving money. Use the baits on the inside and outside where you see the ants foraging and use the Dominon 2L as a spray on the ground and foliage.The Dominion 2L is a non-repellent insecticide that will not cause the ants to scatter.

Protein /Grease feeding cycles

Invict Blitz Granules
(Sorry, only registered and for sale in Fl, GA, LA and TX-Not for sale in other states)

Advance375 A Ant Bait

How to Get R >

Ants may be small, but they make a huge difference in their respective ecosystems. As long as they remain in their native habitat, they contribute to natural processes, such as the decomposition of organic waste, leaf litter, dead insects, and dead animals.

Ants effortlessly work together and collectively sustain their colonies. This coordinated effort is great for their survival, but it won’t be so great for you when they have invaded your home. When you encounter an ant problem in your home or on your property, determining the type of ant you are dealing with will shed light on the steps you can take to eliminate them and prevent future infestations.

What Are Argentine Ants?

Image via Flickr by wolfpix

Argentine ants are an invasive ant species native to Argentina. The widely accepted explanation of how they came to inhabit the United States is as stowaways on ships that were carrying sugar or coffee from Argentina in the 1890s. They began their trek through the southern United States in California. Since then, they have spread to Illinois, Missouri, Arizona, Oregon, Washington, and Texas.

The Argentine ant’s coloration is light to dark brown. As with all other ant species, the bodies of Argentine ants comprise an abdomen, thorax, head, antennae, mandibles, eyes, and six legs.

Argentine ants seem to thrive along the humid and temperate coastal regions of California. This is due in part to the lack of fire ants that live in this immediate area. Argentine ants have uprooted or killed the majority of the native ants, even though many of them are as much as ten times bigger than they are.

Argentine ants often form mega-colonies and have a unique potential to explode in numbers. They can do this because of having hundreds of queens that are responsible for breaking off from an existing nest to start a new colony. Mating takes place in the nest, and even though the mating ants have wings, they are rarely ever seen.

Do Argentine Ants Bite?

Argentine ants do bite, but only as a defensive measure, and they do not have stingers. Due to their aggressive nature, Argentine ants will not tolerate sharing an area with other ants and have no issue with completely displacing or killing off just about any other species of ants except fire ants. Fire ants seem to possess the ability to intimidate the Argentine ants, so they steer clear of areas that fire ants inhabit.

Common household pests are also victims of the Argentine ant’s hostile nature. These ants will kill and eat exposed termites and cockroaches alike. They favor living outdoors but will enter homes to forage for food and water. Argentine ants pose a risk to the inhabitants of houses they have decided to invade. They are attracted to decay and waste and spread bacteria to anything they come in contact with.

The diet of Argentine ants is different for the workers than it is for the larvae and queens. The workers prefer to eat sweet foods such as fruit juices and plant secretions. They will even protect aphids so they can obtain the honeydew they excrete. The workers will gather greasy and protein-based food and carry it back for the larvae and the queens to consume.

Argentine ants may like to forage in homes, but they do not favor living in them. They typically live in damp soil near buildings, plants, sidewalks, or even under buildings. A colony is created as close to food and water sources as possible. They never rest and will work day and night to collect food.

Argentine Ants Control

Before deciding how to deal with Argentine ants, it’s important to know a few things about different ant control methods:

  • Using insecticides in the form of a dust or a spray to treat against ant infestations can stress the colonies and cause them to break apart and create multiple nests.
  • Using ant bait can provide the steady treatment necessary to eliminate entire colonies. It is best to use slow-acting bait to ensure that the bait is spread to the whole nest.
  • You will need to have an understanding of what nutritional needs are required by the species of ant to determine the type of ant bait to use. Different baits provide different dietary values, such as protein, sugar, or carbohydrates.
  • Once you have settled on using ant bait, you will need to be sure that all other food sources have been removed before putting out the bait. When you notice the ants taking the bait, you must not disturb the bait. Otherwise, you may discourage the ants from using the bait as a food source.

Argentine ants do almost all of their feeding from mouth to mouth. This makes them prime candidates for using ant bait as a method of control. When they have discovered the bait and begin to take it, they will transport it back to their nests. This will ensure the introduction of the bait to the entire colony, including the workers, larvae, and queens.

How to Get Rid of Argentine Ants

Argentine ants can be remarkably difficult to get rid of due to the massive number of ants that can exist within a mega-colony. To eliminate these ants, you will have to use a few different approaches. You will need to make sure to thoroughly clean your home and keep it as clean as possible. It would be best if you also used a slow-acting bait as a way to wipe out the entire nest.

As an added precaution, you can use insecticide sprays as a barrier of protection around your home to deter ants from entering your home again. In severe cases where you are not able to get rid of Argentine ants, you can benefit from the expertise of a professional pest control agency. They will be able to identify the type of ants that are infesting your home and develop an effective plan of treatment.

If you are like most people, ants are okay as long as they aren’t in your yard, garden, or home. Once they have invaded your personal space, they can create less-than-pleasant issues that can’t be tolerated. Learning how to identify different types of ant species and how to manage them will help you better protect your family.

‘Alien’ Argentine Ants May Have Met Their Match

Argentine ants (Linepithema humile) are among the most aggressive invasive insects in the United States. But after pushing out native ant species in local ecosystems across the country, the little conquerers may have finally met their match.

Researchers found evidence that another alien species, the Asian needle ant (Pachycondyla chinensis) is chipping away at the Argentine ants’ stronghold.

Asian needle ants have already been found from Alabama to New York City to Oregon, and their venomous stings can cause allergic reactions in some humans.

While studying a supercolony of Argentine ants in North Carolina, researcher Eleanor Spicer Rice, then a doctoral student at North Carolina State University, spotted some Asian needle ants — a strange sight, as Argentine ants usually attack other ants in their territory. To investigate further, Spicer Rice and Jules Silverman, a professor of entomology at NC State, studied how the two species were spread across a 116-acre (47-hectare) office park in Morrisville, N.C. [Gallery: Stunning Photos of the World’s Ants]

In 2008, they found Argentine ants in 99 percent of the sample sites within the study area, while Asian needle ants were found in just 9 percent of the sites. By 2011, the Argentine ants’ reach dropped to 67 percent of the sample sites, while the Asian needle ants had expanded their territory to 32 percent of the sites. The two species shared 15 percent of the sample points, the researcher said.

“This is the first time we’ve seen another ant species take territory from Argentine ants,” Spicer Rice said in a statement. She explained that Asian needle ants might have an edge, because they start reproducing earlier in the spring while Argentine ants remain quite dormant until late April or May.

“The Asian needle ant is moving into forests and urban environments at the same time. And because it is active at cooler temperatures, it could move into a very broad range of territory,” Spicer Rice said.

The researchers say it’s not known how Asian needle ants displace other ant species, but their spread could have negative consequences for local ecosystems, especially if they push out native ant populations that play a crucial role in dispersing plant seeds.

The research was detailed online Feb. 8 in the journal PLOS ONE. The team is now studying why Argentine ants are not fighting back against Asian needle ants, according to a statement from NC State.

Argentine ants have invaded, only to retreat in other parts of the world. They once posed a multi-million dollar pest-control problem in New Zealand, but researchers in 2011 found that huge colonies of the ants had disappeared, possibly because inbreeding may have left them vulnerable to disease.

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