Which ant species are most often misidentified?

Odorous house ant colony.
Photo courtesy of, and copyrighted by, Gene White, pmimages@earthlink.net

We asked Pest Management Professional’s columnists and editorial board members to share which ant species are most often misidentified. Here are some of their responses — including a few extra that didn’t make it into our July print edition.

Paul Hardy: Argentine ants (Linepithema humile). This is now most common ant found in Georgia, and most of the South and Southwest. Always start by inspecting outside before offering any treatment. Look for foraging trails.

Pete Schopen: Acrobat ants (Crematogaster spp.). One of their distinguishing characteristics is their heart-shaped gaster. Here in Illinois, odorous house ants also get blamed for everything and are misdiagnosed all the time.

Mark Sheperdigian: A black ant that’s not tiny is not necessarily a carpenter ant. Field ants (Formica sp.) are medium-sized ground-nesting black ants, but they have an uneven arch to the thorax. Carpenter ants have an evenly rounded thorax and live in trees and cavities.

Judy Black: Pharaoh ants (Monomorium pharaonis). PMPs treat them as if they were a single queen ant species and end up spreading the infestation, due to multiple queens. In general, small ant species — pharaoh, white-footed, ghost, acrobat — can be difficult to deal with. The treatments for all four might be different, and are definitely different for pharaoh. So, it’s best to identify any small species of ant before doing anything. Never make an assumption about small ants.

Ryan Bradbury: Odorous house ants (Tapinoma sessile). There’s interesting technology coming out that identifies the species of pests within traps. The future of general pest as we know it is changing. These are exciting times!

Doug Foster: Pavement ants (Tetramorium caespitum) are often mistaken for odorous house ants, and vice versa. A small hand lens will help show the one segmented pedicel on the odorous house ant.

Dr. Faith Oi: Little black ants, and I’m not talking about Monomorium minimum. This little black ant is ubiquitous, varies in size and shape, and appears in homes across the U.S. It is often described as “sugar ants.” Ensure a proper ID by placing it in a vial/container with alcohol (not a plastic sandwich bag), packing it in a small box, and mailing it to your closest entomology department or company’s technical department.