How to control tawny crazy ants with IPM and a multi-control approach.

The tawny crazy ant, Nylanderia fulva (also known as the Caribbean crazy ant, hairy crazy ant, and Rasberry crazy ant). This little guy has more aliases than P Diddy Puff Daddy Sean John puffy Combs, The classification of this ant in the United States has been a source of constant confusion.

Tawny crazy ant (Nylanderia fulva)
Tawny crazy ant (Nylanderia fulva)

Although long this is a brief summary of two PHD Dissertations I have written it so you can have the most pertinent information regarding the tawny crazy ant.



History and Background of the Tawny Crazy Ant

The Tawny Crazy Ant wasn’t correctly identified until 2012 by a team of researchers lead by Dietrich Gotzek. The Tawny Crazy Ant was first discovered in a Miami hospital in 1990 and was reported by Dr. John H. Klotz, Ph.D. and is co-author of the book Urban Ants of North America and Europe: Identification, Biology, and Management.

The Tawny Crazy Ant originates from Brazil, In the late 1960s and early 1970s, The Tawny Crazy Ant was introduced into Colombia as a biological control agent against leaf-cutting ants and poisonous snakes.

The Tawny Crazy Ant has been documented from Anguilla, Argentina, Bermuda, Brazil, Colombia, Cuba, Guadeloupe, Martinique, Mexico, Panama, Puerto Rico, St. Croix, Lesser Antilles, and US Virgin Islands, In the United States, The Tawny Crazy Ant has been documented in Florida, Texas, Mississippi, and Louisiana

Currently The Tawny Crazy Ant can be found in 24 counties in Florida (Alachua, Brevard, Broward, Clay, Collier, DeSoto, Duval, Hardee, Hillsborough, Indian River, Lee, Manatee, Marion, Martin, Miami-Dade, Orange, Palm Beach, Pasco, Pinellas, Polk, Saint Johns, Saint Lucie, and Sarasota)

The Tawny Crazy Ant from large super colonies and take over vast expanses of land Like other invasive ants, The Tawny Crazy Ant causes disruption in natural ecosystems, affecting native ants, other arthropods, and vertebrates.
Although these ants do not have a sting, worker ants possess an acidopore that they use to project formic acid for defense. They are capable of biting, yet the bite is weak and quickly fades.

The Tawny Crazy Ant is a semi-tropical ant species.

Nesting Habits of The Tawny Crazy Ant

The Tawny Crazy Ant is a successful invasive species, this is could be the result of its omnivorous feeding habits more on this in the feeding habits section, polydomous nesting in which colonies are not confined to a single nest but inhabit several dispersed nests, extreme polygyny, high fertility, high interspecific aggression in which individuals of different species compete for the same resource in an ecosystem (e.g. food or living space)., and apparent lack of intraspecific aggression among themselves. The Tawny Crazy Ant has large colonies containing many queens, workers, and brood which are (eggs, larvae, and pupae). Workers exhibit loose foraging trails and individual ants forage erratically, hence the typical reference to “crazy” ant.

The Tawny Crazy Ant colonies can be found under or within almost any object or void, such as stumps, soil, concrete, rocks, potted plants, mulch piles, in rotting wood, in under pieces of garbage, under flower pots and many objects that retain moisture, areas with a high amount of leaf debris and mulch are ideal places for tawny crazy ants to nest. The potential abundance and diversity of nesting sites can make tawny crazy ant nests hard to characterize, especially in the summer months. Nests primarily occur outdoors, but worker ants will forage indoors, into homes and other structures.

The Tawny Crazy Ant population densities begin to increase with a peak around mid-summer. Population densities remain high through fall but seem to decrease dramatically in winter months. Providing you have winters on south Florida this might not be the case.
The Tawny Crazy Ant is capable traveling long distances. The Tawny Crazy Ant was shown to advance 100 meters per month. The Tawny Crazy Ant colonies can move at a rate of 20 and 30 meters per month through a neighborhood or commercial areas but can exhibit greater expansion rates in rural areas.

The Tawny Crazy Ant demonstrate synanthropic associations with humans which mean they live near and benefit from humans and their dwellings and therefore provide an assortment of problems in homes, businesses, and agricultural settings.

In areas infested with this The Tawny Crazy Ant, large numbers of ants have accumulated in electrical equipment, causing short circuits and clogging switching mechanisms resulting in equipment failure this is a result of the fact that some ants are strongly attracted to both AC and DC electric fields; Shorting of electrical equipment by ants can also be a result of opportunistic foraging and harborage scouting rather than an attraction to electricity. Worker ants could be attracted to the alarm pheromone released when an ant is electrocuted.

Colony Structure of The Tawny Crazy Ant

The Tawny Crazy Ant is polygyne and polydomous; therefore, they are considered a super colony ant species. Polygyne is defined as the presence of more than one queen in a nest and polygamy is defined as the use of two or more spatially separated nests by one ant colony New nests are formed in super colonies by budding; in which one or more queens will leave the original nest and form a separate nest.

Super colonies are then very large communities with multiple queens and many nests that allow workers to mix freely across the community. The lack of aggression allows resource allocation so resources can be used to expand the colony rather than be spent
In the winter, the ants are usually found in only one or a few nests. These nests are referred to as permanent nests. Permanent nests are always occupied and are the nests the ants leave from to form temporary nests in the late spring and summer. Permanent nests are always occupied and are the nests the ants leave from to form temporary nests in the late spring and summer.

In north central Florida, in the spring and summer, the queens produce large amounts of brood causing the ant population to increase rapidly leading to the formation of many temporary nests. These temporary nests allow the ants to spread across the landscape to forage for resources. Temporary nests can be found in or under just about anything in the landscape. If temporary nests are disturbed, the ants will move to another nesting location. As the weather begins to cool in the late fall and winter, the ants may retreat back to the old permanent nest or may form new permanent nests.

Tawny crazy ant colonies can have multiple queens and nests per colony. Having multiple queens per nest leads to a high reproductive potential. In permanent nests, up to 14 queens, 2300 workers, 1000 eggs, 1300, larvae, and 4500 pupae have been found. Temporary nests are much smaller than permanent nests with varying numbers of castes and brood.

The high reproductive potential, nesting strategy and the abundance of the potential of temporary nesting locations allows tawny crazy ants to spread across a landscape. A single colony can cover acres of land, making them an area-wide problem, not just a single-lot problem. The reduction of a tawny crazy ant population on one lot does not guarantee that they the ants will not reinvade from adjacent areas. Tawny crazy ants affect entire communities.

Unlike most ant species, tawny crazy ants from different colonies usually do not fight. Their non-territorial nature is a factor contributing to large populations. However, the tawny crazy ant is highly aggressive against other ant species, often displacing other ants and other arthropod species from areas

Feeding Habits of the Tawny Crazy Ant

The Tawny Crazy Ant derive nutrients from a variety of sources. The Tawny Crazy Ant workers commonly “tend” insects such as aphids, scale insects, whiteflies, planthoppers and mealybugs for their carbohydrate rich excrement (honeydew) a sugar substance. The Tawny Crazy Ant workers are attracted to sweet parts of plants including floral and extrafloral nectaries and over-ripe fruit. Worker ants also kill and scavenge other insects and small vertebrates for protein.

Tawny crazy ants prefer to feed on proteins year-round compared to other food sources. Protein sources in a typical north central Florida lot could include termites, springtails, caterpillars, grubs, spiders, and other ant species.

It is apparent that The Tawny Crazy Ant has surpassed the prevention level of management in and containment appears daunting if not impossible.

Whitmire Advance® Carpenter Ant Bait (ACAB) formulation containing abamectin, is the only commercial bait known to be attractive to The Tawny Crazy Ant .

I personally was able to use Thiquid in a nest area and kill it. See pictures below. Also, notice a Flyer in the circle.

how to control Tawny Crazy Ants with Thiquid
Tawny crazy ant (Nylanderia fulva) Feeding on Thiquid
Tawny crazy ant (Nylanderia fulva) feeding on Thiquid Ant Gel Bait
Tawny crazy ant (Nylanderia fulva) feeding on Thiquid Ant Gel Bait

Food preference and seasonal food change was also documented. Results showed that The Tawny Crazy Ant preferred protein as a food source year-round; indicating that baits incorporating protein should be effective year-round.

Control is usually seen for a short period of time before the ant population resurges.
The control of The Tawny Crazy Ant is difficult due to their high numbers, weak foraging on most traditional ant baits, and the efficacy of pesticides.

Using a broadcast spray at the highest label rate, control was seen for 14 days then the population rebounded. In both of these instances, a reapplication of pesticide would have to be done for continued control.

Note: If you are using sprays in conjunction with baits you must use a non-repellent spray to avoid contaminating the bait.

When dealing with an The Tawny Crazy Ant infestation, a single control method cannot be used because of the super colony structure.

An IPM integrated pest management plan is needed to control The Tawny Crazy Ant infestations. Landscape debris, lawn debris, and trash need to be removed as they provide a place for temporary nest. Trash cans need to be emptied regularly and stored away from structures. To prevent entry into structures, landscape around the structure needs to be cut back so that no branches are touching the structure, and all cracks and crevices around the structure need to be sealed.

Currently, there are no over-the-counter pesticides that effectively control tawny crazy ants.

Some techniques they may use, but are not limited to, include:
Applying a residual pesticide, which the ants must come in contact with to be controlled, around structures to prevent tawny crazy ant entry. If you apply a residual pesticide, be sure not to use water or a broom to remove the dead ants. Instead, use a leaf blower to ensure that the pesticide is not washed or scraped away and will continue to help protect the structure.

Recent studies have shown that populations of the tawny crazy ant are the worst in the late spring, summer, and early fall The sooner in the year a management plan is put into place, the better the chances are the control actions will produce desirable results.

My Plan on how to control Tawny Crazy Ants

The control of this ant species in Miami has been very difficult for home owners to attempt to do it themselves this is the best possible recommendation that can be made at this time

Information on where to buy these professional products or to obtain labels and MSDS Click on the links below.

Use a non-repellent broadcast spray such as Dominion 2L for lawn and perimeter spray at the maximum label rate every 2 months.

Treat all Trees and shrubs that are subject to scale, mealy bug, aphids and whiteflies with Dominion 2L systematic root drench at the lowest label rate.

Use Whitmire Advance® Carpenter Ant Bait around the perimeter and areas where nest are visible.

Use Thiquid ant gel around the structure where trails are spotted.

Remember to also follow all IPM Recommendations herein.
Landscape debris, lawn debris, and trash need to be removed as they provide a place for a temporary nest.

Trash cans need to be emptied regularly and stored away from structures.

To prevent entry into structures, the landscape around the structure needs to be cut back so that no branches are touching the structure.

All cracks and crevices around the structure need to be sealed.


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