Pharaoh, Tawny Crazy Among Toughest Ant Species for PMPs to Control

Santos Portugal, director of quality and technical training, ABC Home & Commercial Services, Austin, Texas, said tawny crazy ants, in general, have enormous colonies that are not limited to just a single property. “In areas where they are established, this species will most likely pose a seasonal threat to customers instead of being a one-time occurrence," he said. "A single treatment may temporarily reduce numbers, but multiple treatments will undoubtedly be needed for season-long management in areas where populations are high. Baits, although potentially helpful if used in conjunction with a liquid insecticide application, are typically ineffective on their own due to the massive numbers in a colony.”

© credit Cory Goeltzenleuchter

Cory Goeltzenleuchter, director of technical services and operations support, McCall Service, Jacksonville, Fla., said both tawny crazy ants and pharaoh ants present challenges, with the slight edge going to tawny crazy ants. "What makes tawny ants so difficult to control is their sheer number within the colony,” he said.  

Gerry Wegner, retired technical director of Varment Guard, Columbus, Ohio, said the most challenging ant species he encountered was not included in our survey (odorous house ant), but that the following carpenter ants can be difficult to control: the eastern black carpenter ant (Camponotus pensylvanicus) and the smaller or nearctic carpenter ant (C. nearcticus), both of which readily invade human structures and establish colonies and satellite nests in the structural wood and insulation of buildings.   “There can be just one carpenter ant nest or up to several nests in a structure, so locating and treating one nest successfully does not necessarily guarantee an end to the carpenter ant problem,” he said. “A simple perimeter treatment, or repeated perimeter treatments, of an infested structure likely will not eliminate colonies located within the structural elements of a building.”

Wegner added that PMPs can most quickly eliminate carpenter ant infestations by inspecting structural features most conducive to occupation by these ants and then focusing corrective measures into those sites.  Problematic structural features can include some combination of decay-softened wood, insulation and cavities/voids where moisture is retained. “Most of the colonies and satellite nests I encountered were in damp sill plates, sliding door track sills/kick plates, deck attachment plates, wood siding and insulation behind it, roof ridge beams, hollow wood columns, and window framing and sills,” he said.

Wegner reminded that some of these sites require the use of a ladder or extension application equipment in order to reach and treat.  He also recommended the use of specialized equipment for detection and treatment may include: thermal imaging (FLIR) device, aerosol-generating/-injecting machine, and battery-powered crack and crevice duster. 

Also choosing carpenter ants as his most challenging ant to control was fellow Midwest pest management professional, Bob Richardson, entomologist at McCarthy Pest Control, St. Charles, Mo.  

“With their ability to create satellite colonies and create multiple nest sites, they are by far the toughest,” he said. “I have found them in curtain rods and even in hollow core closet doors.  They love to inhabit behind the header board of decks and in any wall void.  Looking for primary nesting sites in nearby trees is also a necessity during inspections. As with most ants, temperature during inspections is critical.  When temps are cold, it’s difficult to find evidence.  When primary colonies are in a neighbor’s tree, it adds a new layer of complication.”  

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