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United States Department of Agriculture

Agricultural Research Service

Title: Modeling Temperature-Dependent Range Limits for the Red Imported Fire Ant (Hymenoptera: Formicidae: Solenopsis Invicta) in the United States

Authors
item Korzukhin, Michael - INST. OF GLOBAL CLIMATE
item Porter, Sanford
item Thompson, Lynne - UNIV OF ARKANSAS
item Wiley, Suzanne - UNIV OF ARKANSAS

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 4, 2001
Publication Date: N/A

Interpretive Summary: Scientists working at the USDA-ARS Center for Medical, Agricultural and Veterinary Entomology in Gainesville, Florida and the University of Arkansas School of Forest Resources in Monticello, Arkansas developed a model to predict areas susceptible to invasion by the red imported fire ant, Solenopsis invicta. They predict the future range of the red imported dfire ant within the United States based on climate and its current extreme distributions. To reach that goal, they used a dynamic model of colony growth which depended on daily maximum and minimum soil temperatures. Temperature records at 4,537 meteorological stations within the current and potential range of S. invicta were obtained from NOAA's National Climatic Data Center. At each station, a colony was allowed to grow and reproduce. The map of reproducing colonies was then compared with the current fire ant distribution. After calibration to the current extremes in Arkansas, Tennessee and Oklahoma, they defined four zones of colony success: certain possible, undemonstrated, and improbable. An annual precipitation limit was selected to indicate regions where arid conditions may prohibit growth in non-irrigated areas. Results of the model predict that red imported fire ants will likely move 50-100 miles north in Oklahoma and Arkansas. They will also likely continue expanding into portions of Virginia, Maryland and Delaware in the east and New Mexico, Arizona, California, Oregon, Nevada and maybe even Washington and Utah in the west.

Technical Abstract: We predict the future range of the red imported fire ant, Solenopsis invicta Buren, within the United States based on climate and its current extreme distributions. To reach that goal, a dynamic model of colony growth with two time steps per day was formulated which operates by colony area, S, and alate production, a. Colony growth rate depended on daily maximum and minimum soil temperatures. Temperature records at 4,537 meteorological stations within the current (near 1.5 million km2) and potential range of S. invicta were obtained from NOAA's National Climatic Data Center. At each station, a colony was allowed to grow and lifetime female alate production was calculated. The map of alate production was then compared with the current fire ant distribution. After calibration to the current extremes in Arkansas, Tennessee and Oklahoma, we defined four zones of colony proliferation success: certain, possible, undemonstrated, and improbable. An annual precipitation limit (510 mm) was selected to indicate regions where arid conditions may prohibit growth in non-irrigated areas. Results of the model predict that red imported fire ants will likely move 80-150 km north in Oklahoma and Arkansas. They will also likely continue expanding into portions of Virginia, Maryland and Delaware in the east and New Mexico, Arizona, California, Oregon, Nevada and maybe even Washington and Utah in the west.

Last Modified: 7/24/2014
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