Areawide Fire Ant Project |
2008 Annual Areawide Fire Ant Report.
FINAL REPORT
Areawide Suppression of Fire Ants: Demonstration Project in
D.A. Streett1, A.M. Pranschke1, J.T. Vogt1, Jack T. Reed2, and Anne-Marie Callcott3
1USDA, ARS, Biological Control of Pests Research Unit
2Department of Entomology and Plant Pathology,
3USDA, APHIS, PPQ, CPHST
INTRODUCTION
The USDA-ARS demonstration project for the suppression of imported fire ants has entered its seventh year. In 2005,
The Areawide project integrates biological control agents with the chemical bait products hydramethylnon and methoprene.
METHODS
Our study was conducted at four sites, 2 sites located in
Figure 1. Distribution of imported fire ants in
Chemical Treatment Only:
Site 1. Woodland Plantation, Holcomb, MS, Grenada Co.
MS County Extension Agent- Mr. Steve Winters
Chemically-treated acreage: 253 acres
Peripheral acreage: 1585 acres
Woodland Plantation is located approx. 80 miles northeast of Stoneville, outside the flat lands of the Mississippi Delta. The site was found in the fall of 2001. At that time, vial samples from 100 mounds were collected and inspected for the presence of Thelohania sp. Presence of the disease was not detected. Furthermore, inspections for the presence of the phorid fly were negative. Plots were established and pretreatment data were collected at the end of April and early May 2002. Aerial applications of the combined chemical baits Siege Pro and Extinquish were applied
Figure 3. Digital OrthoQuadrangle photo of Woodland Plantation, Grenada County, with a GPS marked treatment area and numbered ? acre plots. Plots not to scale.
An initial survey of the imported fire ant mounds was conducted prior to the initiation of the demonstration project. We analyzed 50 ant samples, by identifying chemicals found on their exoskeleton, to determine what species of fire ants are located at
Black Imported Fire Ants 8%
Red Imported Fire Ants 2%
Hybrid Imported Fire Ants 90%
(Hybrids are a cross between red and black imported fire ants)
Figure 2 shows a reduction in the average mounds per acre in the area treated with the fire ant bait. Figure 3 shows the area that was treated. In the spring of 2002,
Site 2.
MS County Extension Agent- Mr. Steve Winters
Chemically-treated acreage: 228 acres
Peripheral acreage: 384 acres
Figure 4. Linear graph showing the average mounds per acre throughout the study period.Each yellow line with airplane represents an aerial bait application (application of methoprene and hydromethelnon; 0.75 lbs/acre total). The blue line represents the boundary area (Control) of the site and does not receive bait applications. The pink line represents the area (Treatment) of the site and does receive the aerial bait application. Each marker along the blue or pink lines is a sample date. Dotted lines (blue and pink) denote periods of time with missing data and therefore may not represent actual field conditions.
Figure 5. Digital OrthoQuadrangle photo of
An initial survey of the imported fire ant mounds was conducted prior to the initiation of the demonstration project. We analyzed 50 ant samples, by identifying chemicals found on their exoskeleton, to determine what species of fire ants are located at
Black Imported Fire Ants 24%
Red Imported Fire Ants 2%
Hybrid Imported Fire Ants 74%
(Hybrids are a cross between red and black imported fire ants)
Figure 4 shows a reduction in the average mounds per acre in the area treated with the fire ant bait. Figure 5 shows the area that was treated. In the spring of 2002,
Chemical and Biological Control:
Site 3. Knox Farms, West Point, MS, Clay Co.
MS County Extension Agent- Mr. Perry Kimbrough
Chemically-treated acreage: 253 acres
Peripheral acreage: 319 acres
Knox Farms is located approx. 150 miles east of Stoneville. The site was found in the fall of 2001. At that time, vial samples from 100 mounds were collected and inspected for the presence of Thelohania sp. Presence of the disease was not detected. Furthermore, inspections for the presence of the phorid fly were negative. Plots were established and pretreatment data were collected in May 2002. An aerial application of the chemical baits was applied June 4, 2002.
Figure 6. Linear graph showing the average mounds per acre throughout the study period.Each yellow line with airplane represents an aerial bait application (application of methoprene and hydromethelnon; 0.75 lbs/acre total). The blue line represents the boundary area (Control) of the site and does not receive bait applications. The pink line represents the area (Treatment) of the site and does receive the aerial bait application. Each marker along the blue or pink lines is a sample date. Dotted lines (blue and pink) denote periods of time with missing data and therefore may not represent actual field conditions.
Figure 7. Digital OrthoQuadrangle photo of Knox Farms,
An initial survey of the imported fire ant mounds was conducted prior to the initiation of the demonstration project. We analyzed 50 ant samples, by identifying chemicals found on their exoskeleton, to determine what species of fire ants are located at Knox.
Black Imported Fire Ants 86%
Hybrid Imported Fire Ants 14%
(Hybrids are a cross between red and black imported fire ants)
Figure 6 shows a reduction in the average mounds per acre in the area treated with the fire ant bait. Figure 7 shows the area that was treated. In the spring of 2002, Knox averaged 50 to 60 mounds per acre. Notice the declines in the pink line after each aerial application (yellow line). This is an indicator that the ants are actively searching and consuming the bait
Site 4. Prima Farms, West Point , MS , Clay County
MS County Extension Agent- Mr. Perry Kimbrough
Chemically-treated acreage: 261 acres
Peripheral acreage: 284 acres
Prima Farms is located approx. 150 miles east of Stoneville, just a few miles east of Knox Farms. The site was found in the fall of 2001. At that time, vial samples from 100 mounds were collected and inspected for the presence of Thelohania sp. Presence of the disease was not detected. Furthermore, inspections for the presence of the phorid fly were negative. Plots were established and pretreatment data were collected in May 2002. Aerial applications of the chemical baits were applied June 4, 2002.
Figure 8. Linear graph showing the average mounds per acre throughout the study period.Each yellow line with airplane represents an aerial bait application (application of methoprene and hydromethelnon; 0.75 lbs/acre total). The blue line represents the boundary area (Control) of the site and does not receive bait applications. The pink line represents the area (Treatment) of the site and does receive the aerial bait application. Each marker along the blue or pink lines is a sample date. Dotted lines (blue and pink) denote periods of time with missing data and therefore may not represent actual field conditions.
Figure 9. Digital OrthoQuadrangle photo of Prima Farms,
An initial survey of the imported fire ant mounds was conducted prior to the initiation of the demonstration project. We analyzed 50 ant samples, by identifying chemicals found on their exoskeleton, to determine what species of fire ants are located at Prima.
Black Imported Fire Ants 57%
Hybrid Imported Fire Ants 43%
(Hybrids are a cross between red and black imported fire ants)
Figure 8 shows a reduction in the average mounds per acre in the area treated with the fire ant bait. Figure 9 shows the area that was treated. In the spring of 2002, Prima averaged 30 to 40 mounds per acre. Notice the declines in the pink line after each aerial application (yellow line). This is an indicator that the ants are actively searching and consuming the bait. However, the 2004 fall application did not effectively reduce ant mounds (notice the pink line rise). This may be due to the application being applied immediately after a fog advisory while the ground was still wet, rendering the bait undesirable to the ants. Most of the treatment applications were successful in reducing mounds (notice the pink line consistently below the blue). After the first bait application, fall sampling in 2002 showed a surge in newly formed colonies. Many of these mounds were smaller than a baseball with less than 1000 individuals (large colonies may have as many as 250,000). There also appears to be a declining trend in the control (blue line). This area surrounding the treatment did not receive any bait. The pattern follows in all study sites and, therefore, indicates an environmental influence.
IMPACT
Bait Application Treatments
The trigger in
Suppression of the imported fire ants lasted at least four to ten weeks after bait applications, averaging less than ten mounds per acre (Figs. 2, 4, 6, 8). Mound numbers generally increased by the fall of each year (rise in the pink line indicates more mounds/acre). After the first bait application, fall sampling in 2002 showed a surge in newly formed colonies. Many of these mounds were smaller than a baseball with less than 1000 individuals (large colonies may have as many as 250,000). There also appears to be a declining trend in the control (blue line). The area surrounding the treatment did not receive any bait; therefore, this pattern follows in all study sites and indicates an environmental influence.
Phorid fly Releases
The phorid fly rearing program and phorid field release study were conducted by Dr. J. T. Vogt with the USDA-ARS-BCPRU. The initial phorid fly release was completed in May 2002 at the Knox site in
The fire ant decapitating fly, P. curvatus was first released in two pastures in Clay Co.,
By mid 2006, phorid fly dispersal had expanded over three million acres in
In 2004 P. litoralis was released at Knox Farms in Clay County, Mississippi. P. litoralis was not found after 11 survey days in the fall of 2004 and four survey days in the spring of 2005. No additional releases of phorid flies were made in 2005 or 2006.
Figure 10. Distribution of phorid flies, Pseudacteon curvatus, in Mississippi since released at Prima Farms, Clay County , in 2003.
Thelohania
Imported fire ant colonies were collected from a field site located near
Since July 2002, three attempts have been made to introduce T. solenopsae into two pasture sites in Clay County, Mississippi. In 2002, 82 mounds were each initially challenged with three gms of red imported fire ant brood inoculum. In April 2003, 186 mounds were provided Thelohania-infected brood following the project protocol. Follow-up sampling of the inoculated mounds in the fall of each year failed to yield active infected colonies.
Members of the demonstration project in
No inoculation attempts of the fire ant disease, T. solenopsae, were made in
Pitfall and Bait Attractants
In addition to fire ants, eleven ant species were collected at the demonstration project treatment sites in
Table 1. List of ant species captured at each of the areawide study sites. Names with asterisk (*) were only captured in pitfall traps.
Publications:
Streett, D. A., Vogt, J. T., and Pereira, R. M. 2002. Area-wide suppression of the black imported fire ants on pastures in
Streett, D. A., A.M. Pranschke, and Ann-Marie Callcott. 2005. Areawide Suppression of Imported Fire Ants: Demonstration Project in
Thead, L. G., J. T. Vogt, and D. A. Streett. 2004. Dispersal of the Fire Ant Decapitating Fly, Pseudacteon curvatus (Diptera:Phoridae) in
Vogt, J. T., and Streett, D. A. 2003. Establishment of Pseudacteon curvatus Borgmeier in
Vogt, J. T. and Streett, D. A. 2003. Establishment of the decapitating fly Pseudacteon curvatus (Diptera: Phoridae) in
Vogt, J. T., Streett, D. A., Pereira, R. M., and Callcott, A. M. A. 2003.
Vogt, J. T., D. A. Streett, R. M. Pereira and A. M. A. Callcott. 2003.
Vogt, J. T., D. A. Streett and D. Boykin. 2004. Seasonal characteristics of black imported fire ant (Hymenoptera: Formicidae) mounds in northern