Doing More With Less: What’s Next for Ant IPM?

It doesn’t matter where you are in the country: Ants likely are your No. 1 revenue-generating pest, but not at the top of the list for profit generation. Why? Callbacks. The most managed ants vary by geographic region, but may include carpenter, pavement, odorous house, Argentine, red imported fire, Pharaoh and tawny crazy ants. Recently, manufacturers have made great strides developing broad-spectrum ant control products (both bait and liquid residual formulations). However, government regulation and customer demand is driving the future of ant management towards fewer active ingredients and reduced product application rates or banding patterns. How can PMPs reduce the amount of ant management products used while still satisfying customers and reducing potential callbacks? Use all the tools in your toolbox.

THE USUAL SUSPECTS. The first tools out of the toolbox should always be a hand lens (identification) and a flashlight (inspection). Ant identification is important as structure-infesting ant species vary in nesting sites or number of nests in a colony, food preferences, damage and stinging potential.

After identifying what ant you are dealing with, the next step is a thorough inspection. Communicating with the customer and identifying where they are seeing ants is only one step in the inspection process. It’s also important to find the attraction source (food scraps/storage practices, sanitation, honeydew-producing insects, etc.); access points (cracks and openings around doors, windows and utility lines, plantings too close to the structure, etc.); where the ants are coming from/where they are going (foraging trails); and where they may be nesting. Potential nesting sites include: under landscape stone, concrete slabs, or rock walls; inside downed trees or structural timbers; or oftentimes an accumulation of debris (such as too much mulch or pine straw around a structure that provides ideal nesting conditions).

FIRST-GENERATION TOOLS. For years, nuisance ant control in or around a structure consisted of one tool — liquid insecticide applications. Today, PMPs understand there is no one-trick pony to manage ants and reducing the callbacks associated with them. They must utilize both non-pesticide and pesticide-based tools. Non-pesticide tools can be as simple as a bottle of window cleaner (to disrupt foraging trails); surface cleaner (to clean out a potential food source like a dirty exterior garbage can); or a snow shovel (to remove snow from a roof that could lead to moisture-damaged wood used by carpenter ants for a satellite nest). Other common non-pesticide tools include pruning shears, caulk and a garden rake. Pruning back vegetation that touches the structure removes a major potential foraging route into the structure. Caulk should be used to seal openings around pipes and utility lines, removing many potential access points. A garden rake is a great way to thin out potential overmulching or other landscape materials providing ideal nesting locations adjacent to a structure.

PMPs have many pesticide-based control tools in their toolbox, including many formulation types (e.g., bait, dust, granule, SC/WP), application methods (e.g., broadcast, crack and crevice, spot, void), and active ingredients (e.g., boric acid, fipronil, imidacloprid, indoxacarb). Anytime pesticide tools are used, always remember to read and follow the product label. Label information on allowable application sites, rates, banding patterns, frequency, applicator PPE and environmental restrictions must always be followed.

SECOND-GENERATION TOOLS. Often I am asked what’s the next best thing coming to the industry, or what will we be using 5 to 10 years from now to control pests? My answer is always, “anything that allows us to do more with less.” In ant management, three pertinent next-generation technologies (that may allow just that) are: pheromone-assisted baiting, pheromone-assisted liquid residual sprays and hydrogel-based baits. Pioneering research into these applications has been reported in the last three years, with field test data only recently being published. Pheromone-assisted baiting and liquid residual spraying incorporates synthetic Argentine ant trail/recruitment pheromone into each pesticide formulation. Pheromone-assisted sprays were shown to increase product efficacy through a lure and kill strategy. Ants were recruited faster and remained on a pheromone-treated insecticide application longer leading to greater long-term efficacy (Choe and Campbell 2014).

Pheromone-assisted baiting and hydrogel- based baits are both striving to improve bait program efficacy. The emphasis of these strategies is perfectly summed up by a line from a recent GEICO commercial where raccoons are eating garbage. (“This is terrible…you gotta try it!”) Pheromone-assisted baits increased bait consumption/foraging activity and product efficacy in both lab and field trials (Welzel and Choe 2016).

Hydrogel-based baits are being investigated as a potential new formulation for ant baits. These super absorbent salt crystals can solubilize to a gel-like form and dry out repeatedly while still retaining a toxic pesticide. Preliminary hydrogel ant bait field studies displayed greater than 90 percent efficacy over a two-week period while also minimizing the need for repeated bait applications due to the stability of the formulation (Buczkowski 2016).

While we wait to see what new ant management technologies are around the corner, it’s best to remember the basics. Identify, inspect, and use all your available non-pesticide and pesticide tools.

The author is a board certified entomologist and manager — technical services at Rollins in Atlanta. Contact him at thusen@giemedia.com.