Source: UNIVERSITY OF GEORGIA submitted to
MANAGEMENT OF THE IMPORTED FIRE ANT (HYMENOPTERA: FORMICIDAE) IN GEORGIA
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
TERMINATED
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0188264
Grant No.
(N/A)
Project No.
GEO01565
Proposal No.
(N/A)
Multistate No.
(N/A)
Program Code
(N/A)
Project Start Date
Mar 1, 2001
Project End Date
Feb 28, 2004
Grant Year
(N/A)
Project Director
Gardner, W. A.
Recipient Organization
UNIVERSITY OF GEORGIA
200 D.W. BROOKS DR
ATHENS,GA 30602-5016
Performing Department
ENTOMOLOGY
Non Technical Summary
The red imported fire is rapidly spreading and displacing indigenous ant species throughout the Southeast and other parts of the U.S. A lack of natural enemies to regulate fire ant populations is a major reason for its success in its introduced range. This project examines the development and release of natural enemies within the fire ant populations in Georgia.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
70%
Developmental
30%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2111610113030%
2112130113010%
2151610113050%
2152130113010%
Knowledge Area
215 - Biological Control of Pests Affecting Plants; 211 - Insects, Mites, and Other Arthropods Affecting Plants;

Subject Of Investigation
2130 - Turf; 1610 - Pasture;

Field Of Science
1130 - Entomology and acarology;
Goals / Objectives
1. Conduct a systematic survey of Georgia to characterize the occurrence of indigenous and nonindigenous ant species in the state. 2. Conduct systematic surveys of the red imported fire ant in Georgia to quantify the occurrence and distribution of polygyne versus monogyne colonies, hybrid forms, and natural enemies. 3. Cooperate with the USDA to participate in and evaluate introductions of the protozoan Thelohania solenopsae and phorid flies, Pseudacteon spp., into red imported fire ant populations in Georgia. 4. Quantify the impact of Thelohania solenopsae and Beauveria bassiana for synergistic or additive effects in reducing populations of imported fire ants. 5. Assess and compare the potential of combination of control tactics (i.e., other biocontrol agents, chemicals, etc.) with infections of Thelohania solenopsae and Beauveria bassiana for synergistic or additive effects in reducing populations of imported fire ants. 6. Quantify the efficacy of conventional chemical insecticides as well as commercially available biological control agents against fire ants in agricultural, nursery, wildlife and urban settings.
Project Methods
1. Sites will be selected to insure samples from representative soil provinces and plant habitats in Georgia. Each site will be sampled by a variety of methods, and specimens collected will be identified. 2. Fire ants will be sampled along transects in the state to obtain distribution data on polygyne forms, hybrids and other factors. 3. Both Thelohania and Pseudodacton have been introduced and released in Tift Co. These introductions will be monitored for survival and dispersion. Protocols developed will be used to release in other locations in the state. 4. Bioassays will be conducted to determine the impact of entomopogenous diseases on the reproductive potential and host fitness of the fire ant. 5. Bioassays also will be conducted to determine the interaction of multiple infections of Thelohania and Beauveria in the same fire ant hosts. 6. The program will continue its extensive evaluation of the efficacy of candidate chemical insecticides against the fire ant. Attempts will be made to evaluate the impact of fire ants on wildlife primarily by excluding fire ants from large areas and comparing impacts on wildlife or the food of wildlife species in untreated areas.

Progress 03/01/01 to 02/28/04

Outputs
The red imported fire ant, Solenopsis invicta, remains a serious problem for Georgians. Surveys show that landowners apply more insecticides than herbicides, primarily to combat infestations of the ant. During this project, we completed a statewide survey of ground-dwelling ants, quantified the competitive impact of the fire ant on native ants, identified factors governing successful fire ant infestation of habitats, evaluated novel chemistries and application methods for control, and attempted introductions of a microsporidian pathogen and a phorid fly for biocontrol of the pest. Most recently, we successfully established the phorid parasitoid at two central Georgia locations, and we have observed natural expansion of the flies released in northern Florida and eastern Tennessee into Georgia. We also confirmed the predation of foundling fire ant queens by certain native ant species in tree canopied areas, supporting efforts to conserve these native species. Our research helped support the labeling of a fast-acting chemistry formulated either as a bait or granule; this is now available to Georgians.

Impacts
Results of distribution surveys and release protocols have defined tactics for utilizing phorid flies and other biocontrol agents in integrated pest management programs against the imported fire ant in Georgia.

Publications

  • Brinkman, M.A., and Gardner, W.A. 2004. Red imported fire ant control in nursery plant containers, 2003. Arthropod Manag. Tests 29:G39.
  • Brinkman, M.A., and Gardner, W.A. 2004. Red imported fire ant (Hymenoptera: Formicidae) control in nursery pots treated with Beauveria bassiana and bifenthrin. J. Entomol. Sci. 39:175-187.
  • Brinkman, M.A., and Gardner, W.A. 2004. Mortality of ant (Hymenoptera: Formicidae) pest species exposed to sodium hydrogen carbonate. Florida Entomol. 87:324-329.
  • Brinkman, M.A., Gardner, W.A., and Ipser, R.M. 2004. Red imported fire ant (Hymenoptera: Formicidae) mortality following exposure to sodium hydrogen carbonate (NaHCO3). J. Entomol. Sci. 39:188-201.
  • Brinkman, M.A., Gardner, W.A., and Ipser, R.M. 2004. Fire ant (Hymenoptera: Formicidae) activity in simulated electric utility boxes treated with NaHCO3. J. Entomol. Sci. 39:679-680.
  • Ipser, R.M., and Gardner, W.A. 2004. A review of the scientific literature on the biology, ecology, and foraging strategies of two invasive ant species in North America. Sociobiol. 44:485-503.
  • Ipser, R.M., Brinkman, M.A., and Gardner, W.A. 2004 A survey of ground-dwelling ants (Hymenoptera: Formicidae) in Georgia. Florida Entomol. 87:253-260.
  • Wiltz, B.A., Suiter, D.R., and Gardner, W.A. 2004. Laboratory evaluations of liquid toxicants against red imported fire ants. Proc. Red Imported Fire Ant Conf., Baton Rouge, LA, pp. 51-55.


Progress 01/01/03 to 12/31/03

Outputs
The imported fire ant occupies all Georgia counties. We found that a hybrid form (Solenopsis invicta X S. richteri) infests areas north and west of Interstate 85; S. invicta infests southern areas. Distribution will determine release tactics for biocontrol with phorid flies. Pseudacteon tricuspis was released in Spalding Co in 2003. Establishment has not yet been confirmed. Statewide surveys of ground-dwelling ants identified 85 species representing 33 genera. This serves as a baseline for evaluating impact of fire ants on native ant species. Chemistries were evaluated for fire ant control in efficacy trials; none were more effective than currently available materials.

Impacts
Results of distribution surveys and release protocols have defined tactics for utilizing phorid flies and other biocontrol agents in integrated pest management programs against the imported fire ant in Georgia.

Publications

  • Brinkman, M.A., and Gardner, W.A. 2003. Fire ant management in potted nursery soil. Georgia Green Industry Assoc. J. 14(2):25.
  • Brinkman, M.A., and Gardner, W.A. 2003. Red imported fire ant control with insecticides and natural products. Ctr. Appl. Nursery Research Proj. pp. 1-8.
  • Gardner, W.A. 2003. More than a nuisance. New South Gardener 1(4):18.


Progress 01/01/02 to 12/31/02

Outputs
A 3-yr survey of ground-dwelling ants in Georgia was completed with 92 species collected from 27 sites. At least 5 species have not been previously reported from Georgia; another has not yet been described. Comparisons of open vs canopied habitats showed that native ants limit colony founding by imported fire ants, Solenopsis invicta, in canopied habitats. Fall 2000 releases of phorid flies in Tift Co. apparently failed in that searches have yet to detect flies at the release site. Efficacy trials of labelled and registered insecticides against imported fire ant were conducted in Houston, Pike, Spalding and Tift counties with some new chemistries showing potential as control agents. Laboratory bioassays of potential control agents showed that rates lower than those recommended on labels may provide suitable control of fire ants, diatomaceous earth enhances the activity of entomogenous fungi against workers, and sodium bicarbonate may control ants infesting electrical junction boxes.

Impacts
We are developing an integrated approach to the management, rather than the eradication, of the imported fire ant in Georgia. Microbial agents, parasitoids, cultural tactics, and chemical insecticides provide landowners and practitioners a increased options of control.

Publications

  • Brinkman, M.A. and Gardner, W.A. 2002. Red imported fire ant control in nursery plant containers, 2001. Arthropod Management Tests 27:G57.


Progress 01/01/01 to 12/31/01

Outputs
To date, over 65 species of ants have been collected and identified in systematic surveys from 26 locations across the state of Georgia. Seven species - Stenamma diecki, S. schmitti, Crematogaster minutissima smithi, Myrmica americana, M. punctiventris, M. spatulata, and Pheidole septentrionalis - are new records of collection from the state. Studies of canopied vs open areas show that Solenopsis invicta is the prevalent species in open areas; there is greater diversity of ant species in canopied vs open areas; Prenolepis imparis, Paratrechina vividula, Aphaenogaster picea, and Formica sp. prey upon S. invicta reproductives in canopied areas, and; P. imparis and Pheidole tysoni move from ecotonal areas to compete with S. invicta on baits in open areas. Surveys for the S. invicta - S. richteri hybrid show that this form occupies an area west and north of U.S. Interstate 85 in Georgia. Adults of Pseudodacton tricuspsis, a parasitoid of S. invicta, have not yet been recovered from the Tift Co. site at which parasitoids were released in October 2000. Although the microsporidian pathogen Thelohania solenopsae caused the decline and eventual failure of colonies into which it was introduced in 2000, there is no evidence of its spread to neighboring colonies or areas. Field efficacy testing has yielded registration of an additional formulation of hydramethyinon bait for homeowner use against S. invicta.

Impacts
The identification of ant species that prey upon and compete with Solenopsis invicta is a first step in developing systems of natural regulation of this ant pest. Further characterization of these interactions should enhance efficacy and implementation. Classical biocontrol approaches of introducing Pseudodacton tricuspis and Thelohania solenopsae into the state have not yet proven successful, but much is being learned to adjust future introductions. These and other introduced nonindigenous biocontrol agents will also help in naturally regulating the pest in Georgia and the Southeast. Knowledge of the distribution of the hybrid S. invicta - S. richteri form will assist in these releases as the hybrid is more susceptible to selected parasitoids that are being evaluated for release.

Publications

  • Brinkman, M.A. and Gardner, W.A. 2001. Use of diatomaceous earth and entomopathogen combinations against the red imported fire ant (Hymenoptera: Formicidae). Florida Entomol. 84:658-659.
  • Brinkman, M.A., Gardner, W.A., Ipser, R.M. and Diffie, S.K. 2001. Ground-dwelling ant species attracted to four food baits in Georgia. J. Entomol. Sci. 36:461-463.
  • Brinkman, M.A., Gardner, W.A. and Buntin, G.D. 2001. Effect of red imported fire ant (Hymenoptera: Formicidae) on Rhinocyllus conicus (Coleoptera: Curculionidae), a biological control agent of musk thistle. Environ. Entomol. 30:612-616.