INDOOR OR OUTDOOR?

Are you capitalizing on the latest "vogue" pests — ants? This diverse group of insects offers a formidable challenge to those PCOs who are up to the task. By using a wide variety of techniques for controlling ants, you will be ready as their numbers continue to increase. Yes, you may bait for ants outdoors, and in other cases you may provide a perimeter treatment that provides temporary relief, but as ants become more plentiful will your company be prepared to execute the best control strategy in a variety of situations? The key to ant control is the ability to commit the time and effort necessary to provide specialized treatment strategies. You must have enough flexibility to accept that a new infestation may require a whole new game plan. Both indoor and outdoor strategies may be needed.

It’s the beginning of ant season and, depending on what part of the country you’re in, the phones have started to ring with customers in newly "suburbanized" areas wanting to know how you can get rid of their ants. Calls range widely based on the particular ant problem, i.e., "They’re in my kitchen," "They’re crawling across the wall in the living room," "They’re coming in the front door of the house," etc. What message do these statements immediately convey? Ants are complex creatures and there are many different pest species with different behaviors so the first thing you must do to effectively suppress an infestation is know which ant species you are dealing with. Identification is truly the keystone to successful ant management.

You don’t have to be an entomologist to become familiar with the various species of pest ants that inhabit your part of the country; there is plenty of information available on ant identification. Some identification pictures and a hand lens (15-30X) or a moderately priced dissection microscope are all that you need to be on your way. Also, remember that you can take advantage of university extension resources in your particular state. An entomologist there may be able to steer you towards even more specific identification information.

Sharing some of the specifics of biology or behavior that will be pertinent to the control strategy can also enhance your professional presence if it is shared with the customer. In today’s information age, people not only want to get rid of their pest problems, they want to know exactly what it is they are dealing with and what service you are providing to satisfy their needs.

ANTS MARCHING. The industry has recently experienced a decrease in the incidence of cockroach calls while ant problems are on the rise. Are there more ants today than there were eight years ago? Probably not. Many have speculated the driving factors behind these changes — and likely there are a number of factors, instead of one — that are at play. Nevertheless, one likely cause for the influx of ant calls is the rapid expansion into rural areas from more urbanized settings. We know that this is occurring at unbelievably rapid rates in some parts of the country where major cities continue to expand outward into what were once old woodlots or farm fields.

Like other insects, ants have been around for millions of years and their survival is based on their ability to adapt to changes within their surrounding environment. To be successful, as insects are disturbed, populations have to be able to adapt to or exploit changes around them. For instance, new housing communities built where there are still wooded lots are more likely to encounter carpenter ants. Structures with accessible high-moisture areas are highly susceptible to infestation by a variety of house-invading ants. Structures that are surrounded by plants that aphids feed on are attractive to ants since many ants feed on the honeydew produced by these insects.

WHICH TREATMENT? Now that you have successfully identified the ant species you are dealing with, you must still follow the basics of pest management to achieve control. Where are the ants coming from? Most pest species of ants dwell outdoors, whether their nests are in or above the ground. Workers from these species may enter the structure in search of food or water but will return to the outdoor nest if not disturbed. There are a few species, the Pharaoh ant in particular, that do nest primarily indoors, however, depending on the time of year and prevailing outdoor temperatures, even these indoor-dwelling ants will readily travel outside in search of food.

Finally, some species of ants have colonies both in and out of the structure. The Argentine ant is probably one of the best-known examples of this. Argentine ant colonies can relocate rapidly in response to environmental stress (including a residual insecticide perimeter treatment) and cooler temperatures can trigger them to enter a structure. These colonies have multiple queens and can effectively start satellite colonies if needed. Knowing the origin of the colony naturally permits you to direct control efforts where ants are living. In other words, a thorough outdoor perimeter application of residual insecticide coupled with removal of debris such as woodpiles, scrap lumber or other excessive debris, would do little to affect an indoor infestation of Pharaoh ants, however, both techniques are reasonable preventive efforts if you are targeting carpenter ants.

There are a variety of control methods and insecticide formulations available for both the outdoor and indoor treatment of ants. I will concentrate on some techniques here, but be advised that there is much more than what I have space to talk about. Always revert back to the first step in the control strategy — identification. What is the particular ant species and what are the specific biological nuances of that species?

OUTDOOR TREATMENT. Outdoor treatments encompass a wide variety of techniques. Searching for colonies around the perimeter of the house and then treating directly with residual insecticides can be effective, however, care must be taken so that the mound or nest is thoroughly soaked with product to ensure total colony elimination. Void treatments can be made if access to the void is possible. An insecticide dust or residual aerosol application also can be made in these areas. Holes may need to be drilled in these instances depending on access points. Drilling into voids requires a variety of equipment, depending on what materials were used to construct the walls. Of course, a review of these procedures in a training manual is a good idea before you start drilling. Also, be aware of the void type — will insecticide be able to penetrate? Am I using the proper formulation? If there is debris or insulation in the void, an aerosol may be better for penetrating than a dust.

One of the most prolific control options for ants today is baiting. So much is written about ant baits but the most important item to remember is that ants can shift food preferences at different times of the year and at different times during the life of the colony. For this reason it is difficult (if not impossible) to come up with a single bait matrix that all ant species (or even one ant species throughout the course of its life cycle) will readily accept. There are now baits available that provide two or more different food sources to improve the likelihood that baits will be accepted by foraging workers. Other baiting systems employ both liquid and solid foods so that foraging ants have a choice of two or more different baits from which to choose, thus increasing the likelihood that they will consume at least one of them.

Because of their popularity in the past 10 years, there is a lot of information available about baiting and we learn more as we go along, but there is no substitute for experience. In my opinion, the two most important baiting techniques are getting the bait as close to the colony as possible and removing other competitive food sources that are around while you are placing the baits. This applies for both indoor and outdoor baiting strategies. Finally, unlike cockroach baiting, it’s a good idea to visit the treatment area soon after placement (within 24 hours) to determine if ants have located your baits and if they are feeding on them or not. If not, more bait should be placed or existing bait should be moved to other trails.

The last type of outdoor ant treatment is perimeter treatments with residual insecticides. Perimeter treatments involve spraying residual insecticides around the area at the direct base of the foundation and the foundation itself, depending on the treatment. A perimeter treatment may provide some measure of control — at least for a while — however unless other measures are taken (mainly location and treatment of specific colonies), perimeter treatments will likely be ineffective as a stand-alone treatment for invading ants. This method can even exacerbate existing problems with certain ant species (such as Argentine ants) by cutting off satellite colonies from the main colony resulting in two major source points of infestation instead of one. In short, avoid outdoor perimeter treatments for ants unless incorporated as part of a total management plan.

INDOOR TREATMENT. Indoor ant treatment programs may require some techniques different from those used outdoors. Of course, one fundamental difference is that the ants have already invaded the structure. Whether the colony is established inside or out, there are ants to deal with inside. A first visit still requires you to check outside and inside the structure for ant signs, but in addition you may have to remove visible ants. This can be achieved with a contact insecticide or by simply removing the ants with a cloth or sponge. Another technique is to use a soap and water or mild cleaner formulation to immobilize the ants as you remove them. Of course, these are probably only foraging worker ants representing only a fraction of the entire colony. If you do not make an attempt to locate the colony, any treating that you do will likely provide only temporary satisfaction.

Void treatments with dusts or aerosolized residual insecticides can still be used, depending on the species you are dealing with. Any hollow wooden frames or other objects will need to be inspected and treated if ants are detected in these areas. Insecticide dusts can also be employed at the floor level if ants are detected trailing along walls or other straight edges. Dusts can be applied underneath carpets or directly into seams or cracks that ants are using where the wall meets the floor or where two edges meet.

By far, the method of choice for indoor ant treatments today is baits. The actives available and the many forms that they come in make this a good choice for a variety of ant species. The PCO has a variety of solid baits in both bait station and granular form for outdoor use. In addition, several gels and pastes can be applied with a syringe or applicator "gun." In many cases, foraging worker ants feed primarily on liquids and there are a number of liquid bait formulations. The liquid formulations are used in large sentry stations primarily for outside perimeter placement. In large commercial accounts these stations may even be used as monitors. In addition granular baits are used both in stations and as a broadcast application around the perimeter of the house.

Gel and containerized baits are the forms of choice for indoor treatments. These baits can be conveniently placed into cracks and crevices where ants are trailing or entering a structure, yet they are still out of site for the customer. As with outdoor ant baiting, a quick follow-up visit and repositioning of baits that are not being visited is a good practice. Of course, there are always exceptions and acrobat ants, crazy ants and carpenter ants are notoriously difficult to control using baits due to their habits, particularly their complex feeding preferences.

NON-CHEMICAL METHODS. There are a variety of indoor and outdoor non-chemical treatment measures that you can work into your treatment program, but it is important to remember that these methods are usually not completely effective on their own. Coupled with directed insecticide applications, they can greatly improve control efforts. In some instances, such as alteration of high humidity or high moisture situations for carpenter ants, non-chemical control can be a highly effective preventive measure — perhaps one of the most important.

Other non-chemical control measures for outdoor control include sealing off entryways into the structure. This can be a daunting task given the size of most ants as they can potentially gain entrance through the smallest of cracks and crevices. Removal of plant and wood debris from contact with the foundation, walls or roof of the structure, as well as general sanitation, are acceptable outdoor techniques. As for non-chemical control inside the structure, some of the same rules apply. Sanitation is important, as is sealing off potential entrance ways and inspecting wood for moisture problems. Correcting these situations by installing proper air venting equipment are all methods that will help prevent ant infestations.

CONCLUSION. None of our urban pests are easy to control, but, I think most agree that some of them are more complex based on behavior and are therefore difficult to treat. From the standpoint of diversity, ants are one of the more difficult groups that PCOs face. On the other hand, there is a lot of good information available from industry and university researchers that can help guide us in effective control strategies. As ants continue to receive so much attention and as populations begin to grow in rural and urbanized areas alike, use the seemingly endless amount of strategies, techniques and control methods available to PCOs to grow your ant business.

The author is a research scientist at SC Johnson, A Family Company, in the worldwide consumer products RD&E insect control division. He can be reached at rkopanic@pctonline.com.