Editor's Note: This is the fifth in a series of excerpts from the soon-to-be-published Eighth Edition of the Handbook of Pest Control. The long-awaited book will be available in June. For ordering information, contact PCT Books Manager Fran Franzak at 800/456-0707Controlling ants with baits, while convenient, requires knowledge of the target pest and an understanding of how and why baits are effective. What follows are 10 ant baiting tips that will help any pest management professional perform ant control in a more timely and effective fashion.
1. The biggest mistake made with ant baits is to place them and then forget about them until the next scheduled service visit. At the very least, ant baits should be checked within one week, however, the best follow-up period is the next day. Are the ants finding the bait? Has there been noticeable ant feeding on the bait? If not, switch baits, and if more trails are found, place additional baits. Baits cannot work if they are not fed upon by the target ants. 2. Place baits as close as possible to the ant colony. If an acceptable food source is available close to the colony's location, that food source is likely to be more heavily exploited. When possible, place ant baits near where the trail is exiting a wall or crack in a slab.3. Place ant baits along edges and corners wherever possible since ants like to trail along "structural guidelines" formed by the edges of cabinets, the edges of a wall or a crack in concrete, along corners, the edges of landscape timbers, the edge of a tack strip under a carpet, along wires and plumbing pipes, etc.
4. Place baits in electric outlet boxes in walls, especially when dealing with pharaoh ants because these ants most often use electric wires to move throughout buildings. Ant bait stations do not fit in these boxes, so a gel ant bait placed in a piece of plastic straw will usually be needed.
5. Remove other potential food sources by advising the customer of the importance of cleaning up food particles, grease deposits, etc. as much as possible.
6. Skimping on bait placements is another important and frequent mistake made in using baits for ants. Each active foraging trail needs to be baited because that trail could be from a separate colony, especially in the case of pharaoh ants. Follow-up inspections are important for identifying new ant trails.
7. Don't place baits on treated surfaces or apply insecticides over bait placements.
8. Outside bait placements are a must, particularly for pharaoh ants that commonly forage outside during warm weather. In fact, observations by the author indicate that most foraging is done outside rather than inside in many pharaoh ant infestations. Inspect outside for trails and place at least one bait placement along each trail.
9. With the coming of autumn, the nectar in flowers and nectaries decreases or disappears and the honeydew is washed from the plants by rains. During spring, aphid and mealybug populations are at very low levels, which reduces the available amount of a preferred food source. Under these conditions, sweet-loving ants, such as the Argentine ant, may feed much more readily on the ant baits. The fall and spring of the year, therefore, may be the best times to use ant baits for this ant and others.
10. Some ants just do not feed on baits and certain ant species are very dif-ficult, if not impossible, to control with baits. Crazy ants, ghost ants, carpenter ants, Argentine ants and acrobat ants his-torically have been difficult to eliminate using baits. In most of these cases, these ants may feed on the bait but not long enough to severely impact the colony. Manufacturers are continuing work on developing effective baits for carpenter ants and other difficult-to-control species.
A DUAL STRATEGY. Baiting is best used in combination with other treatment measures. The key to controlling infestations of most pest ant species is to find and treat the colony directly with the appropriate insecticide. Typically, only 5% to 10% of an ant colony is out foraging at any one time, so treatment of foraging trails leaves most of the colony alive. Time spent in tracing foraging trails is well worth the effort.
Failure to inspect outside to find outdoor colonies or foraging trails is the primary reason most ant control services are unsuccessful. A PCO experienced in ant control can quickly locate the source(s) of ant in-festations most of the time. Addressing these sources directly, together with correction of contributing conditions and possibly a baiting program, is the best strategy for long-term results.
Sidebar: MORE STEPS TO SUCCESSFUL CONTROL
Inspection: Once the ant has been properly identified, an inspection will be necessary to determine where the colony is located, where activity is present, whether other ant species are present, and whether contributing conditions exist. The client should be consulted to learn where, when and for how long ants have been seen. The floor plan of the infested structure or property can be diagrammed to assist in developing a clear picture of the infestation. Such diagrams are especially helpful when dealing with pharaoh ants.
Prebaiting: If ants are not easily found, it may be very useful to place small drops or ribbons of jelly (e.g., mint apple jelly) or other pre-baiting materials (e.g., raw liver) in suspected areas to help locate the ants. This method is known to work well for many species of ants and, although it takes some time, such efforts may assist in developing the treatment plan.
Following Trails: Ants typically follow defined trails from the nest to any food or water source and these can lead an inspector back to the colony's location. Finding that initial trail to follow is sometimes difficult and requires patience and a good set of eyes. Ants follow "structural guidelines" along most of their trails. Such guidelines include the edges and corners found on landscape timbers, along sidewalks and along the edges of brick veneer on houses. Garden hoses and gutters also supply ants with a path to follow.
Listening Devices: A standard stethoscope is very helpful in confirming the presence of a carpenter ant colony in a void or wood. Electronic stethoscopes make it even easier to hear colonies of these ants.
Displaced Soil: Soil-nesting ants, such as pavement ants, fire ants, big-headed ants and field ants, all excavate soil to create their nest galleries. Piles of displaced soil is a quick indicator of ant activity whether these are seen in a lawn, on a sidewalk, at the edge of a porch or on the floor of a garage.
Items Lying On The Ground: Any item lying on the ground could have ants living under it and should be lifted to inspect underneath. Carrying a sprayer containing an appropriately labeled insecticide saves time by permitting quick treatment of ant colonies as they are discovered. Piles of lumber, firewood, bricks or leaves all make ideal sites for many ants, such as Argentine, crazy, odorous house and little black ants. Such piles need to be in-spected for activity, treated as necessary and then removed by the customer for long-term control.
Moisture-Damaged Wood: Any wood that contains high levels of moisture is attractive to carpenter ants and acrobat ants. Ask homeowners about past water leaks, roof repairs, etc. and inspect those areas. Signs of excess moisture, such as fungi, stains and peeling paint, should also be investigated for ant activity.
Habits Of The Ant: Always keep in mind the habits of the target ant. This information assists in recognizing potential nesting sites of the ant during the inspection.