Tramp Ant, Tetramorium bicarinatum

Characteristics:

  • Coloration: head, thorax and pedicel reddish-brown, abdomen black
  • Head roughened with parallel grooves
  • Body of worker 1/4 inch in length (monomorphic)
  • Antennae 12-segmented with a 3-segmented club
  • Epinotum with a pair of spines
  • Have multiple queens

Little has been published on the biology of this ant. However, it is a close relative of the Guinea ant, Tetramorium guineense (Fabricius), another tramp species of African origin commonly found in the Gulf Coast region where it occurs most commonly in the urban area. These ants feed on dead and live insects and as house pests are almost omnivorous, feeding on fruits, vegetables, meats and grease. Feeding habits appear to be similar for these two species. Winged male and female Tetramorium bicarinatum have been observed in the laboratory every month of the year. Inseminated queens probably found colonies without the aid of workers.

Distribution

Tetramorium bicarinatum is of African origin introduced into the United States through human commerce. It is commonly found in the southern region of the United States, in South Carolina, Florida and Texas. Since it is easily spread as a stowaway among things transported by humans, it is referred to as a “tramp ant.” This species has become common in many areas along the Gulf Coast of Texas. It is not an aggressive invader of structures, but is commonly found along sidewalks, driveways, in and around flowerbeds, around foundations of buildings and in rotting wood.

They have large polygynous colonies with polydomous nesting habits. The nests may be widely distributed in a given area. The workers are monomorphic; about 1/4 inch long, the head and thorax is roughly sculptured, reddish-brown and the abdomen is black. Queens are only slightly larger than the workers. In nature they take liquid secretions (honeydew) from plant sucking insects such as aphids, mealy bugs, and scales. They tend and protect these insects and use these as a food source. They show a distinct preference for foods with high sugar content.

Management

The most important step in controlling this ant is to locate the nest and treat it directly to destroy the colony. To help in locating the nest, the ants may be baited with sweets such as sugar, honey, jelly or a piece of bacon placed where ants are seen. When ants have located and fed on these foods they can be traced to their nesting site. After baiting the route, treatment can be made in cracks and crevices where they are returning with food to the colony nest. Treatments with an appropriately labeled dust insecticide can be puffed into holes and give good coverage of voids where the ants will be killed or carry the insecticide back into the nest, resulting in the death of others.

Outside, use a perimeter spray with an insecticide as a wettable powder formulation and treat the foundation as high as two feet and three feet out into the soil. This will control existing colonies and prevent invasion by new colonies.