[Ant Control] Focus On Florida

Although the quote has been used many times before, I think it is quite adequate here: Forrest Gump informed the lady sitting on the bench next to him that his mother used to say, “Life is like a box of chocolates… You never know what you’re gonna get.”
Ant control in Florida poses a similar situation. With more pest species existing in the Sunshine state than all others — the pest management professional never knows what he/she is going to get when they answer that pest ant call. There are fire ants and carpenter ants, as well as a host of other tramp ant species in Florida. Many experts have instructed us before that you simply can’t just do “ant control” if you want to be successful. Proper ant control demands respect of species-specific ant behavior and biology. Putting a smile on the homeowner’s face by managing their pest ant problem requires a deeper understanding of each different ant species’ nuances.
In 1995, Klotz et.al., published an article in the journal Florida Entomologist describing the key urban pest ant species in Florida. Both commercial and household pest control settings were sampled. The study identified eight species as key pests (see table below):
• Red imported fire ant
• Ghost ant
• Crazy ant
• Florida carpenter ant
• Pharaoh ant
• Tortugas carpenter ant
• Big-headed ant
• Paratrechina ant
Additionally, more than 25 other ant species were encountered in year-long studies that were considered “occasional invaders.” That’s almost 40 species of ants that pest management professionals may have to identify and battle in the name of “ant control.” Since the 1995 study there have been at least two other ants in Florida that have reached pest status: Technomyrmex albipes, the white-footed ant, has been receiving a fair amount of press in both research articles and the Florida pest control industry in recent years and the Caribbean crazy ant, Paratrechina pubens, is the most recent pest ant in southern Florida counties that has an absolutely explosive potential for spreading (Tucker, 2006).
Regardless of which of these species you are going up against, positive ant identification and a thorough understanding of specific behaviors/nesting habits will help you better provide favorable results for your client.
For the remainder of this article let us review some of the basic information about behavior, worker identification, nesting sites and their location. If you can find the location of foraging ants, and hopefully their nests around the home or structure, you will greatly increase your chances of ant suppression and go a long way towards making your client happy.

Crazy Ant (Paratrechina longicornis). The crazy ant gets its common name from its characteristic rapid and seemingly random foraging patterns exhibited by workers. This species does not always appear to follow trails like many other pest ant species. Worker ants are capable of foraging long distances and for this reason the crazy ant becomes one of the more difficult invader ants to deal with when searching for the nest. Crazy ant colonies can contain between 500 and 2,000 workers and may have as many as 50 queens in a large colony. This species lives in a series of satellite colonies that are all connected by foraging lines. These satellite colonies are very mobile and can easily relocate if environmental conditions threaten their present location.
New colonies are formed through budding from the original colony (a behavior whereby all life stages and at least one or more reproductive females and workers leave one established colony to establish a new nesting site). Reproductive swarms occur during the summer throughout their range in the United States, and in many parts of Florida crazy ant swarms can occur year round. Crazy ants are best identified as having long 12 segmented club-less antennae. Workers are relatively small (2 to 3 mm), are monomorphic (of only one size) and have one node between the thorax and abdomen. They appear dark brown to black in color with a slight iridescence. Nests can be found in quite dry as well as moist habitats. Their ability to adapt to both soil types allows them to maximize nesting opportunities. Nests are not easy to locate as they do not build mounds or elevated structures. Their common nesting sites around urban structures include: in soils underneath landscaping wood, mulched areas, stone beds, under logs in wooded areas, firewood in the yard, potted plants (both in the soil and underneath the pot itself) and basically any kind of debris material that is in contact with the ground. Crazy ant workers are, like many other ants, omnivorous.
Their diet can include live and dead insects, plant exudates, seeds and fruits of most types. In the household they can be attracted to a wide variety of food types including high protein as well as high sugar foodstuffs. Baiting for crazy ants can be particularly frustrating at times due to their tendency to refuse many bait matrices with high sugar content. They favor instead higher protein foods during this time. Locating trailing ants is usually easy near the outside of the structure on the sides of the home, on sidewalks, patios and driveways. Remember to look for the characteristic “crazy” (and fast) moving individuals. Try to locate workers that are carrying food (presumably back to the colony) to pinpoint the nest. If they are feeding on liquids, spotting workers returning from a food source is not always that easy. Workers that are carrying a full load of liquid will have a swollen abdomen, but this may be difficult to spot on these tiny ants. Although sometimes difficult to manage, the best time for finding crazy ant trails is in the evening when the weather is particularly dry and hot (Tucker, 2006).

Ghost Ant (Tapinoma melanocephalum). The ghost ant was once referred to as the “tramp ant” because of its reputation of being one of the most successful tramp ants, which are ubiquitous throughout tropical and subtropical areas around the globe. This species is so fastidious that it is even capable of surviving (and thriving) in temperate regions via greenhouses and other buildings that provide tropical living conditions. Because of its vagabond lifestyle enabled by world trade and commerce it is difficult to determine from where the ghost ant originated.
This species is found in Florida from the far south to many northern regions and is well established as a pest in the urban environment. Ghost ants are difficult to see (thus their name?). Their pale color and extremely small size (workers are between 1.3 and 1.5 mm in length) make them almost invisible on certain substrates.
Workers are monomorphic with a 12- segmented antennae that gradually thickens towards the tip (no club). Although a good hand lens or stereoscope is required to see it, ghost ants have only one node on the pedicel. The head and thorax of a worker ghost ant appears dark brown with the legs and abdomen being translucent or white.
Like the odorous house ant (Tapinoma sessile), the ghost ant will give off a distinct acrid odor of rotten coconuts when crushed. This species is capable of establishing nests in both indoor and outdoor settings. Outside of the structure, ghost ants can build small nests in dead tufts of grass, plant stems, dead curled leaves and other detritus, plant bedding and potted plants, within cracks in the residential structure itself, or between spaces on decking and other wooden structures where environmental conditions are favorable. Their relative small size and small sub colony building behavior requiring limited amounts of space makes locating ghost ant nests for this species quite difficult as they can be almost anywhere! Often these small nest sites are used for as little as a few days before the entire nest is relocated to another area.
Inside of the structure, ghost ants will most likely be found in wall voids or other appropriate voids between cabinets, appliances, and other movable pieces in the household that are near a water source. Ghost ant colonies contain multiple queens and sub colonies are formed by budding. Budding occurs with many of our pest ant species and is one of the major reasons total ant elimination around a structure is so difficult and requires diligent and thorough inspection practices. Ghost ants’ feeding preferences vary. They consume dead insects for protein as well as honeydew from sucking insects they are capable of tending. They  also feed opportunistically on mites and other tiny or nearly microscopic arthropods. In the urban setting they can be observed exploiting a wide variety of sweet and protein-rich food scraps.
Ghost ants are one of the many pest ant species that are difficult to bait. They may readily consume sweet (sugar) based baits in one account at one time, and completely reject them in favor of a protein-based or fat-based bait in a different account another time. Although manufacturers continuously try, there is no single bait base that will always work for ghost ants. It is therefore advisable to be prepared with a number of different bait products when attempting to effectively bait this ant. Foraging worker ants can be observed and followed to locate nesting sites and thus provide access to an entire sub colony.
 
White-Footed Ant (Technomyrmex albipes). This is one of the latest pest species to grace the red carpet of the Florida pest control scene. The white-footed ant is a native of Japan but was first identified in Florida in 1991 and were thought to have inhabited Florida since the mid-1980s.
This species has caused quite a stir in the state of Florida because of its success in adapting and colonizing newer and far reaching locations. In fact, several quarantines are in effect at some major agricultural areas. Although this ant is currently confined to the southern half of Florida, its potential to spread is quite good. Workers are 2.5 to 3 mm in length and the head is as long as it is wide. The antennae are comprised of 12 segments and there is one node on the pedicel. Individual workers are dark brown to brownish black in color and look much like the little black ant (Monomorium minimum) from a distance. Their legs are not actually white but a light yellowish brown color.
This ant is capable of rapid growth of absolutely huge colonies. Reports indicate that single colonies can contain millions of individuals. Furthermore, a large percentage of these individuals can be female reproductives. Mating flights consisting of tens of thousands of reproductives can result in rapid spreading, and like the other two pest ants we have already discussed the white-footed ant can readily ‘bud,’ creating new satellite colonies with ease. Another biological advantage particular to this species is the ability to produce what are referred to as “trophic eggs.”
The workers of most pest ant species supply food to the larvae by regurgitating food that they bring into the nest, feeding it to the legless larvae via trophallaxis. While this is a biologically advanced system that works quite well for many ant species, the white- footed ant takes this a step further. Instead of repeated feeding of larvae via trophallaxis, workers can digest food themselves and create the aforementioned tropic egg. This “egg” contains all of the nourishment that is needed for the larvae to develop without the need for further contact with other worker nurse ants.
In short, the white-footed ant’s biology creates the perfect storm for a pest invasion. The nesting sites of the white-footed ant are usually found outside of a structure and are quite numerous. Their nests are usually above the ground, often found in trees, shrubs, at the base of palm fronds, between logs in a woodpile, under bark of a tree as well as in many man-made structures, old cars, boats, and in cracks and crevices on the outer wall of the structure itself (between bricks, fascia boards, shutters, window panes, etc.). Foraging workers can be spotted in single lines or branching trails, most often spotted on vertical surfaces (walls in the structure) and plants (outside).
The food preferences of this ant vary like most others. They will readily consume dead insects and other dead animals as a major protein source, and will acquire honeydew from both aphids and scale insects as well as nectar from a wide variety of flowers as a main source of carbohydrates. Of course, they become a problem to us when their foraging indoors takes them to food scraps and other food resources inside the structure. Because of their sheer numbers an actively foraging colony can cause quite a stir among homeowners. Baits are generally recommended as the only effective control strategy that should be used for this particular pest ant. This pest has received a lot of research attention in Florida, and white-footed ant specific control strategies are still being developed and honed by researchers and pest management professionals alike as we learn more about this invasive species.
Conclusion. There are about 40 species of pest ants in Florida. Understanding the specific behaviors and habits of each is difficult but the more you study and understand the better targeted your baiting and treatment (insecticide and non-insecticidal) programs will become.  

Literature Cited
Creighton, W.S. 1950. The Ants of North America. Bulletin of the Museum of Comparative Zoology. 585 pp.
Hölldobler B., Wilson E.O. 1990. The Ants. Belknap Press of Harvard University Press. Cambridge, MA. 732 pp.
Klotz J. et.al. 1995. A survey of the Urban Pest Ants (Hymenoptera: Formicidae) of Peninsular Florida. Florida Entomologist. 109-118.
Mallis, A. 1990. Handbook of Pest Control. 7th Edition. Franzak & Foster Co. Cleveland. 1152 pp.
Tucker, Jeffrey. 2006. PCT Ant Management Seminar. Chicago, IL.

The author is a senior research scientist at SC Johnson & Son, Racine, Wis., in the Pest Control Division of the company’s Worldwide Consumer Products Business. He can be reached at rkopanic@giemedia.com