White Footed Ant

We have a country full of exotic, displaced species of animals, from rats to snails to birds to bugs. Some of these established problems are ants, such as the Red Imported Fire Ant and the Argentine Ant, two of our most troublesome species of ants in the United States. Now we have another recent import, called the White-Footed Ant, which derives this common name from the distinctive white ends of their legs.

The White-footed Ant, whose scientific name is Technomyrmex albipes, is a native of some of the islands of Japan, but as early as 1922 scientists believed it was migrating to many other parts of the world as a hitchhiker with human activities of shipping and travel. It quickly spread to many Asian countries, Australia, New Guinea, Guam, South Africa, and Hawaii, where it is found on most of the occupied islands.

In 1986 the White-footed Ant was first discovered in Florida, but considered a novelty and a minor concern as a pest species. By the early 1990’s there were more and more complaints of the presence of this species, and by the end of that decade it was becoming a very large problem in Florida. By the year 2000 it was confirmed to be established in 6 Florida counties and reported in several others. The White-footed Ant also was reported in Southern California around 1986, and may be established there as well.

Is this a dangerous ant?

No, fortunately T. albipes is not a stinging ant, and really presents no particular threat to human health, anymore than any other home-invading ant species. It is a very small ant, about the size as the common little black ants called the Argentine Ant, and as a “single-node” ant it has no stinger.

They also have not been reported to cause any structural damage, the way Carpenter Ants do. If there is a dangerous side to them, the White-footed Ant may encourage the presence of other kinds of pests. Like most ant species this one likes sweet materials, and in nature they find their sugar fix by feeding on the sweet drippings given off by scale insects, aphids, and mealybugs. These are pests on our landscape shrubs and trees, and often are very important pests in agriculture, affecting the production of our food. When ants “tend” aphids for their honeydew they serve as protectors as well, driving off predators and parasites that might otherwise kill the plant pests.

Why are they a problem?

Like many pest ants the big problem with the White-footed Ant is simply a nuisance problem. We just don’t like hordes of ants swarming over our kitchen counters, and this ant is well suited for doing just that. It has HUGE colonies of workers – possibly as many as 1 million ants in a colony, and typically several hundred thousand. Since a colony of ants may allow up to 10% of them out to forage for food at any one time you potentially could have tens of thousands of ants wandering through your kitchen to see what mischief they can get into.

Also like some other species there are many queens in a single colony, which may have numerous “satellite” colonies branching out from the main one. Each queen is capable of laying eggs, so the potential for creating large colonies very quickly is very high.

Here are some more characteristics of the White-footed Ant, and why they contribute to its being such a problem:

  • High reproduction potential – new colonies formed by swarming (winged adults flying to new areas) or “budding” (new colonies simply branch off of the main one).
  • Enjoy a variety of foods – prefer sweet materials, but also feed on protein from other insects or foods found in our homes.
  • Food digestion is unusual – most ants offer food they have gathered to the larvae, which digest the food and regurgitate it back to the adult workers. If the food was poison bait this allows all workers to ingest it and be killed. The White-footed Ant has a group of workers that lay sterile eggs, and it is these eggs that are consumed by many adult ants in the colony as well as by the larvae. Thus, they avoid eating bait products we might use.
  • Tiny size of the workers allows them to enter any structure.
  • They are very sensitive to the presence of pesticides, and may avoid surfaces that have been sprayed, even moving away to form new colonies when they are separated from their main colony.

Where would we find their nests?

This species will build their nests in a wide variety of locations. In Hawaii they are known to construct “tents” in the crotches of trees or under loose bark, perhaps high up in the canopy of the tree. They may nest in dry, rotting logs, within hollow trees or the hollow galleries made by other insects in the wood. In structures they have been found in attics, wall voids, under roof shingles, hollow voids of furniture, in boxes, or outdoors in leaf litter, under rocks or wood piles, and many other places.

Within this nest the White-footed Ant is very unusual in the ant world. The initial Queen lives for about 1 year, and is replaced by one of her offspring when she dies. This replacement Queen mates with a male and begins producing numerous offspring called “intercastes”. These are wingless, but are reproductives that are capable of laying eggs, and may form as much as 50% of the population of the colony. Obviously this creates a huge ability to lay lots of eggs and expand the colony.

At some point of the life of the colony “budding” may take place, whereby a wingless reproductive leaves the colony, along with a large number of workers who carry larvae and pupae with them, and a new colony is started a short distance from their parent colony. Thus, you might observe these mass migrations of ants, carrying their white babies in their mouths.

How will we get rid of this ant?

This may be a difficult problem. Like almost any other pest ant the ultimate control relies on eliminating the colony, not just killing off a trail of workers that are out and about, foraging for food. As we discussed, though, this is more difficult for the White-footed Ant than for many other species of ants.

It is believed that the use of ant bait methods will be the best approach to managing this species, but a great deal more patience and diligence may be required. It may be a good idea to contact a local, licensed Pest Control company, as they may already have experience in the control of this pest, and will have the tools to deal with it already in hand. As mentioned, the use of pesticide sprays will give instant relief and gratification, by killing the trails of ants that are observed at the time. However, this trail represents a small percentage of the ants in the colony, and may even aggravate the problem by forcing some foragers away from their colony to start new colonies to deal with in the future.

Source: BugBattalion Florida