Common Name: | Elongate Twig Ant |
Other Common Names: | Mexican twig ant, Mexican ant |
Genus / Species: | Pseudomyrmex gracilis (syn: Pseudomyrmex mexicanus) |
Size: | Workers 5/16-inch to 2/5-inch (8-10 mm) in length |
Type of Beneficial: | Insect predator |
Type of Metamorphosis: | Immature stages appear different from adults (i.e., complete metamorphosis) |
Beneficial Stage(s): | Adults |
Prey: | Prey on a variety of small insects, especially lepidopterous (butterfly and moth) larvae |
Occurrence: | Widespread across the Galveston-Houston region (more abundant than most gardeners are likely aware). Adults are solitary hunters. |
Mounted Specimen? | Yes (mounted specimen for viewing available in insect collection at County Extension Office) |
More Information
Originally from Mexico, the Elongate Twig Ant now ranges from Argentina to Texas and the Caribbean, and has invaded Hawaii and Florida. This colorful, large, lithe ant is found throughout the warmer regions of North America.
Elongate Twig Ants are wasp-like in appearance, between 5/16-inch to 2/5-inch (8 to 10 mm) in length. They also have large, prominent eyes that are oval-shaped. They move in quick, short dashes and will dart around branches if disturbed.
A close-up view will reveal scattered, erect hairs on its two-segmented, bicolored (dull orange with dark brown shading) petiole or abdomen. The head is mauve to black with large, oval eyes and a twelve-segmented antenna.
Elongate Twig Ants prey on live insects (especially lepidopterous larvae) and collect honeydew from sap-sucking insects. Some reports include fungus spores as a secondary food source.
Elongate Twig Ants can be arboreal (tree-dwelling) ants, but are typically seen on shrub vegetation and hardscapes such as arbors. Gardeners sometimes encounter them when pruning shrubs and trees. A single Elongate Twig Ant queen occupies each nest, which can occur high up in large trees or in hollow dry grass twigs.
Nests are small and inhabited by only a few individuals. There is a single small entrance which is barely wide enough for two or three ants to pass one another. Most human encounters with Elongate Twig Ants involve just a single ant on the prowl for prey as they are solitary hunters.
Some entomologists list the Elongate Twig Ant as a pest or nuisance since it may sting if handled or if it becomes entrapped between clothing and skin. We have encountered numerous Elongate Twig Ants over the years while maintaining the Master Gardener Demonstration Garden adjacent to the Galveston County Extension Office. During that time, just one Master Gardener has received an Elongate Twig Ants sting she was wearing shorts when she happened to sit on an Elongate Twig Ant! She reported the sting to be similar to that of an imported fire ant sting (she still works in the Demonstration Garden but now looks down before sitting!).
Fortunately, Elongate Twig Ants are rarely found inside a home and colonies are highly inaccessible. Control of Elongate Twig Ants is almost never necessary unless a nest or a large population occurs around children play area or around people with high sensitivity to insect bites/stings.