Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Thelohania solenopsae as a factor of fire ant populations

Author
item Oi, David

Submitted to: Society for Invertebrate Pathology Annual Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: August 11, 2007
Publication Date: August 9, 2007
Citation: Oi, D.H. 2007. Thelohania solenopsae as a factor of fire ant populations. Society for Invertebrate Pathology Annual Meeting Proceedings.p.100.

Interpretive Summary: The inadvertent introduction of fire ants into the United States over 70 years ago initially resulted in large-scale efforts to eradicate the invasive pest. Fast-growing populations and ability to occupy diverse habitats made fire ants a dominant arthropod in infested regions and very difficult to eradicate. Current control strategies in the U.S. now focus on reducing populations to tolerable levels at specific sites, typically with insecticides. Thelohania solenopsae is a pathogen of fire ants that debilitates fire ant queens and eventually causes the demise of fire ant colonies. Reductions of infected fire ant populations by over 60% in the field signify its potential usefulness as a biological control agent. Perhaps the most compelling effect of T. solenopsae is the delay in re-infestation in areas cleared of fire ants by insecticides. The use of T. solenopsae and other biological control agents provide a potential opportunity for the regional suppression or at least an impediment to the expansion of fire ant populations.

Technical Abstract: The inadvertent introduction of fire ants into the United States over 70 years ago initially resulted in large-scale efforts to eradicate the invasive pest. Large populations, mobility, and ability to occupy diverse habitats make fire ants a dominant arthropod in infested regions and very difficult to eradicate. Current control strategies in the U.S. now focus on reducing populations to tolerable levels at specific sites, typically with insecticides. The fire ant pathogen Thelohania solenopsae was discovered in the 1970’s in South America, but not until the 1990’s were reductions in the field formally documented with this pathogen. Introductions of T. solenopsae into red imported fire ant populations in the U.S. spread and are self-sustaining, primarily in the fire ant social form that contains several queens per colony. T. solenopsae infected sites had population reduction of over 60% and infections in colony founding queens. Perhaps the most compelling effect of T. solenopsae is the delay in re-infestation in areas cleared of fire ants by insecticides. The use of T. solenopsae and other biological control agents provide a potential opportunity for the regional suppression or at least impediment to the geographic expansion of fire ants.

Last Modified: 12/19/2014
Footer Content Back to Top of Page