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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Imported Fire Ant and Household Insects Research » Research » Research Project #426807

Research Project: Invasive Ant Biology and Control

Location: Imported Fire Ant and Household Insects Research

Project Number: 6036-32000-048-00-D
Project Type: In-House Appropriated

Start Date: Sep 8, 2014
End Date: Sep 7, 2019

Objective:
Objective 1: Develop advanced integrated pest management methods by improving the understanding of fire ant biology and by expanding biologically-based control of fire ants through detailed genetic, behavioral, physiological, chemical, and ecological studies of fire ants and their natural enemies. a. Employ metagenomics techniques and biological control prospecting to discover additional natural enemies of introduced fire ants. b. Characterize the genetic architecture of the Gp-9 supergene involved in regulation of fire ant colony social form. c. Develop natural enemies of fire ants as classical biological control agents or biopesticides by evaluating their effectiveness, determining host specificity, developing methods for rearing and release, and formulating more effective biopesticides. d. Develop novel biologically-based fire ant control by identifying the behavioral and semiochemical underpinnings of fire ant mating flights and colony establishment. Objective 2: Develop advanced integrated pest management methods by improving the understanding of the biology of invasive pest ants other than fire ants and by expanding options for their management and surveillance. a. Improve control of tawny crazy ants: 1) refine integrated management strategies; 2) evaluate natural enemies; and 3) determine whether crazy ant semiochemicals can be used to enhance baits and improve surveillance/detection methods. b) Develop or improve control methods for other important invasive ants (e.g., Argentine ant, little fire ants) through evaluation and consolidation of current or new control methodologies. c) Establish a collection database and repository for fire ants and other pest ants to facilitate discovery of natural enemies, genetic studies, and taxonomic identifications. Objective 3: Determine impacts of climate and climate change on potential distributions of invasive ants.

Approach:
1. a) Fire ants (Solenopsis invicta) from the native range will be collected and used as source material to create cDNA expression libraries. Detailed bioinformatics analysis of resulting sequence data will be screened to identify potential fungi, viruses, protists, and non-hymenopteran eukaryotic parasites. North American fire ant colonies will be exposed to fire ants collected from South America and observed for signs of pathology. These colonies will be examined using various molecular analyses and microscopic methods to determine the etiological agent. b) A linkage map will be developed to identify all of the genes in the Gp-9 non-recombining region. Linkage disequilibrium between the Gp-9 genes and social form will be estimated with several different statistical methods. Products and functions of the genes comprising the Gp-9 supergene will be inferred by bioinformatic analysis. c) Natural agents will be evaluated for their suitability as control agents against U.S. populations of the fire ant by establishing their host specificity, mode of dissemination (formulation), efficacy, virulence, mode of action, mass rearing, and field release. d) The role of semiochemicals in fire ant biology will be established and possibly exploited as a control agent by exposing colonies and/or individual ants to extracts or synthetic chemicals and recording behavioral changes. 2. a) Effective and alternative control methods will be investigated for the tawny crazy ant by treating infected areas with soil applied systemic insecticides or lures and evaluating for efficacy. The transcriptome of the tawny crazy ant will be sequenced and examined for the presence of potential natural enemies. Promising potential natural enemies, including the tawny crazy ant virus, will be tested to determine efficacy and safety. Seasonal phenology of tawny crazy ant colonies will be established to better direct control efforts by excavating nests monthly and quantifying different stages. b) For tawny crazy ants and other invasive pest ants, e.g. Argentine ant little fire ants, the contents of well-developed ant exocrine glands will be chemically identified and subjected to behavioral bioassays to determine the effect of pheromones on ingestion of baits, bait discovery, field efficacy evaluations, and the effective longevity of attractant/bait formulations. Where attractive pheromones have not been already identified, a Y-tube olfactometer bioassay will be used to isolate and identify active compounds. c) A pest ant database and repository will be assembled using existing electronic data and specimens from labs across the country. Maps for existing pest ant collections will be generated and used to guide future collection efforts as needed. Future specimens and collection data will be systematically incorporated into the repositories. 3. Climate matching protocols in Climex 3.0.2 (Hearne Software, Victoria, Australia) will be used to predict potential future ranges of 15 exotic pest ants. Distributional data will be categorized as rural and urban with extreme outliers noted and eliminated when appropriate (e.g., detection in green houses).