A newly invasive species of pest ant is making its way across the southeastern United States. Since discovery in Texas in 2002, tawny crazy ants (formerly Raspberry crazy ants) Nylanderia fulva (Mayr) have expanded their range to include 28 counties in Texas, as well as parishes and counties in Louisiana, Mississippi, Alabama, Georgia and Florida (Fig. 1). This rapid range expansion has presumably been assisted by the movement of infested materials. These ants invade new areas very rapidly and population densities have been observed to reach extraordinary levels. In urban habitats, tawny crazy ants become an extreme nuisance as they forage around, on and inside structures. Additionally, they have been implicated in the damage and destruction of a wide variety of electrical components and equipment. Tawny crazy ants are known to decrease arthropod density in the systems they invade. They are becoming a serious pest of agricultural systems as well, through infestation of hay bales, direct impacts on commercial honeybee colonies, and by influencing increases in population densities of insect pests of plants (including ornamental and agriculturally important plant species) (Fig. 2). These ants represent a challenge that will require diligence from the pest management industry to solve.
Positive identification of any pest insect species is the first step to ensuring proper management. Tawny crazy ants, while conspicuous when occurring in large numbers, are very difficult to identify without high resolution magnification and experience. If unsure of identification, please contact personnel at the Texas A&M University Urban and Structural Entomology laboratory for assistance (contact information below).
Biology and Behavior:
- Loose and erratic foraging trails
- Extraordinarily dense populations
- Will nest under any available material (potted plants, debris, landscaping objects, etc.)
- No conspicuous mounds
- Terrestrial and arboreal, these ants will readily move onto trees and shrubs that are available to them
- Populations of these ants consist of many queens. This aspect of colony life allows for high reproductive capabilities and elevated invasion success.
- Educate customers regarding the difficulties associated with managing this species of pest ant.
- Consult with property owners to request assistance with removal of all possible nesting sites.
- Diligent planning for treatment is necessary for successful management.
- Careful calculations of necessary amounts of pesticides to be applied are critical to successful tawny crazy ant management.
- Perimeter treatments of structure AND treatment of surrounding landscape with residual insecticide appears to be the best management approach.
- Frequent post-treatment observations of the effectiveness of management approach are advised.
Rollins Urban & Structural Entomology Facility
Texas A&M University
2556 F&B Rd
College Station, TX 77843
ATTN: Robert Puckett