Control of the Introduced Pest Solenopsis Invicta in the United States

Abstract

The black imported fire ant, Solenopsis richteri, was introduced around the early 1900s while the red imported fire ant, Solenopsis invicta probably entered in the late 1930s or early 1940s. Since their introduction, populations of S. invicta have not only expanded their range throughout the southeastern and southwestern United States, but the total number of colonies has greatly increased, especially in states such as Texas which has a greater proportion of multiple queen colonies than colonies with a single queen. Various cultural methods have been tried in which mounds were knocked down during cooler months by dragging steel beams across fields, using different tillage methods prior to planting crops, or burning fields in efforts to reduce or eliminate S. invicta. Contact insecticide treatments are advantageous in that they act quickly, and are applied directly on the mound, thus mainly affecting fire ants while minimizing exposure to non-target ants.