Fire Ant Research at the Ames Plantation

Tennessee Fire Ant Research and Education Team
by Pat Parkman and Karen Vail

In 2003, the Tennessee Fire Ant Research and Education (FARET) was formed as a collaboration between the University of Tennessee Institute of Agriculture and Tennessee State University Institute for Agricultural and Environmental Research. FARET’s core team members include Dr. Karen Vail, UT Extension Urban Entomologist and Associate Professor; Dr. Patrick Parkman, UT Institute of Agriculture IPM Coordinator; Dr. Jason Oliver, TSU Research Assistant Professor; and Dr. Tahir Rashid, UT Entomology & Plant Pathology Post-doctoral Research Associate. The primary mission of FARET is to develop imported fire ant (IFA) management strategies for the state’s nursery industry and to provide educational programs for nursery producers in counties affected by IFA infestations and in areas where emerging infestations are likely.

FARET projects include developing a drip irrigation insecticide delivery system for tree root balls; developing a laboratory soil bioassay test for potential control products; evaluating and demonstrating insecticide treatments in nurseries and pastures; establishing a fire ant laboratory at the UT Extension office in Franklin Co.; developing and distributing a 6-part PowerPoint presentation for Extension agents on fire ant biology; determining the geographic distribution of the red, black and hybrid fire ants in Tennessee and management; and determining the establishment and spread of the parasitic phorid fly Pseudacteon curvatus in the state. Also, the UT fire ant website (http://fireant.utk.edu/) was launched which contains information on all aspects of IFA identification, biology, impact and management.


Parasitic Phorid Flies Alive and Well in Tennessee
by Pat Parkman and Karen Vail

In 2000, the fire ant parasitoid Pseudacteon curvatus was released at Ames Plantation and at two farms in eastern Tennessee. Subsequent sampling for the fly the following year indicated that it had not become established and the releases were deemed failures. However, in July 2004, P. curvatus adults were collected in Hamilton Co. near Chattanooga (ironically, during a release of another biotype of P. curvatus). A later release in 2002 in Franklin Co. was also successful based on collections in 2003. These findings prompted a survey in late summer 2004 of fire-ant infested areas surrounding the 2000 and 2002 release sites.

Fire ant mounds were sampled at release sites and at approximate 5-mile intervals along highways leading away from release sites. Sampling consisted of digging into a mound, crushing or electrocuting (with a modified cattle prod) workers to release alarm pheromone, and observing the disturbed area to detect and collect flies attracted to the disturbance. Collected flies were returned to the lab for identification. Mounds at 113 sites in 25 Tennessee counties were sampled for P. curvatus. Mounds located in northern counties of Alabama, Georgia and Mississippi were also sampled.

P. curvatus was collected at 73 of the sites in 21 Tennessee counties, including all of the 2000 release sites. Sampling results indicate that the fly, although not detected in the year after its release, was apparently established at the release sites after the 2000 releases. The greatest distance a fly was collected from any release site was approximately 61 miles from Ames Plantation. Flies were collected at all six sites sampled in two Georgia counties; and in three of five sites sampled in four Mississippi counties. The flies collected in Georgia and Mississippi appear to be of the population originating from the 2000 releases in Tennessee. No flies were found at the four sites sampled in one Alabama county.
Results of the 2004 survey indicate P. curvatus is established throughout most of the fire ant-infested areas of Tennessee. In west Tennessee the fly has spread to over 3700 square miles from the release sites at Ames Plantation (see map). Although we don’t expect the fly alone to control fire ants, it may help to prevent its movement into un-infested areas. Surveys to document further spread of the fly are planned for summer 2005. Also, fire ant plots established at Ames Plantation before 2000 will be re-sampled in 2005 to determine the impact of 5 years of exposure to phorid flies. Potential impacts include reduced fire ant populations and increases in diversity and abundance of other ant species.

Links for information on fire ant control:
Imported Fire Ants in Tennessee
http://fireants.utk.edu

General Information on Fire Ants (This information is from Texas A&M University)

Publications and Factsheets on Fire Ants (These publications are available from Texas A&M University)