ARS | Publication request: Phenotypic and Genotypic Characters Associated with Polygyne Hybrid Imported Fire Ant

Submitted to: Midsouth Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 29, 2009
Publication Date: March 17, 2010
Repository URL: http://hdl.handle.net/10113/40819
Citation: Garlapati, R.B., Cross, D.C., Caprio, M.A., Sabanadzovic, S., Chen, J. 2010. Phenotypic and Genotypic Characters Associated with Polygyne Hybrid Imported Fire Ant. Midsouth Entomologist. 3:26-32.

Interpretive Summary: The imported fire ants are a significant pest in agriculture and great hazard to public health. Two species of imported fire ants were introduced into the United States: red imported fire ants in 1930.s and black imported fire ants in 1920’s. Hybrid between these two species was found in 1980’s. The presence of a zone of hybridization was confirmed in central to northern Mississippi and Alabama, southern Tennessee and northwestern Georgia. Hybrid fire ant colonies are better adapted to cooler and more northerly latitudes than red imported fire ants. As in red imported fire ant, colonies with multiple queens were found in hybrid imported fire ants. Scientists in Department of Entomology and Plant Pathology, Mississippi State University teamed up with scientist in USDA-ARS to study the origin of polygeny in the hybrid imported fire ants. The knowledge generated from this study will help us to better understand the behavior, biology and spread of the hybrid imported fire ants.

Technical Abstract: A study was initiated to identify the origin of polygyny in the hybrid imported fire ant (Solenopsis invicta x richteri) and to confirm the association of polygyne phenotypic and genotypic characters. Gp-9, a major gene in imported fire ants, is associated with the expression of social form. The association of phenotypic and genotypic characters in a hybrid imported fire ant colony is strongly indicated by identification of multiple inseminated queens in a colony and sequencing the critical region of Gp-9(1,300 base pairs) in individuals with the polygyne allele. A 100% match of Gp-9Band Gp-9b alleles and concordance in the critical amino acid substitutions of the Gp-9 locus in the hybrid fire ant with S. invicta Buren provides the evidence that polygyny in the hybrid imported fire ant is derived from S. invicta.