Submitted to: Imported Fire Ants Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/20/2003
Publication Date: 9/20/2003
Citation: Vogt, J.T., Streett, D.A., Pereira, R.M., Callcott, A.A. Mississippi areawide program: unique aspects of working with black and hybrid imported fire ants. Imported Fire Ants Conference Proceedings: 59. 2003.
Interpretive Summary: Implementation of the Areawide Suppression of Fire Ants Program in northern Mississippi provides a unique opportunity to study black and hybrid imported fire ants, and to apply the latest control technologies against them. Information on the Areawide Program can be found at http://www.ars.usda.gov/fireant/. The Program is designed to implement integrated pest management against fire ants, using insecticidal baits in combination with biological control organisms (parasitic phorid flies and disease). Mississippi study sites (2 in Clay County and 2 in Grenada County) contain a mixture of black and hybrid imported fire ants, while sites in other participating states (Florida, South Carolina, Texas and Oklahoma) contain red imported fire ants. Until 1972, black, red and hybrid fire ants were not clearly recognized in the U. S. Published work on the two species and their hybrid from 1986 to the present is biased toward red imported fire ants by about 9 to 1, even though black imported fire ants are just as serious a pest where they occur and hybrid fire ants occupy a broad band across central Mississippi, Alabama, and Georgia. The Areawide Program's implementation in Mississippi will provide new information to researchers and landowners on integrated pest management of black and hybrid fire ants, and will benefit the public as biological control organisms become established and spread throughout the range of the ants.
Technical Abstract: Implementation of the Areawide Suppression of Fire Ants Program in northern Mississippi provides a unique opportunity to study black and hybrid imported fire ants [Solenopsis richteri Forel (BIFA) and S. invicta x richteri (HIFA), respectively], and to apply the latest control technologies against them. Published information on the biology and ecology of black and hybrid imported fire ants is scarce relative to published reports on red imported fire ants (S. invicta Buren) (RIFA). The Areawide Suppression of Fire Ants Program is being implemented in Florida, Oklahoma, South Carolina, and Texas, at sites inhabited exclusively by RIFA, and in Mississippi, at sites with BIFA and HIFA. A wide range of mound densities (mounds / ha) was recorded at the Areawide Program sites [40 to 560 (Mississippi), 240 to 1,880 (Florida), 140 to 700 (South Carolina), 140 to 1,340 (Texas), and 140 to 720 (Oklahoma)]. Low mound density at the Mississippi sites led us to increase the size of sampling plots to record a sufficient number of mounds per plot. Dipteran parasitoids in the genus Pseudacteon (Diptera: Phoridae) are an integral part of the Areawide program. A strain of P. curvatus Borgmeier from Argentina strongly preferred BIFA to RIFA, with an intermediate preference for HIFA. This strain of P. curvatus was rapidly introduced and established in one of the Mississippi Areawide treatment sites. The other states involved in the program have released P. tricuspis, which exhibits a strong preference for RIFA. The other biological control organism currently being utilized in the Areawide program is the microsporidian Thelohania solenopsae Knell, Allen and Hazard (Microsporida: Thelohaniidae). To date, attempts to introduce this pathogen into HIFA and BIFA colonies at the Mississippi Areawide site have not resulted in spread of the pathogen between colonies. Thelohania solenopsae infects South American RIFA and BIFA colonies at similar rates; however, field infections in the U.S. tend to predominate in polygyne RIFA areas. Several differences exist between RIFA, BIFA and HIFA that required consideration prior to implementing the Mississippi component of the Areawide Suppression of Fire Ants Project. Since comparative studies are lacking, attempts to establish additional parasites and pathogens at the Mississippi sites will yield new information on BIFA, HIFA, and potential for biological control.