Effects of broadcast red imported fire ant (Solenopsis invicta) control products on non-target ant species

Currently, the red imported fire ant, Solenopsis invicta Buren infests over 300 million acres of land in the U.S. Many infested states are listed under the USDA-APHIS Red Imported Fire Ant (RIFA) quarantine. As of 2008, Virginia is not a quarantined state. However, RIFA have been documented repeatedly in Virginia since 1989. The possibility that RIFA is established has caused Virginia’s Department of Agriculture (VDACS) to consider placing certain Virginia counties under the quarantine. Under the quarantine, VDACS will no longer treat RIFA in regulated counties. During this transition period preceding the quarantine, the need for RIFA control product evaluations is paramount. The current VDACS method for controlling RIFA involves treating each mound with Amdro® Fire Ant Bait (0.73% hydramethylnon; Ambrands, Atlanta, GA) followed by an acephate mound drench. However, individual mound treatments are time consuming and ineffective. Advion® and Top Choice® are broadcast treatment products with proven fire ant control efficacy. It is reasonable to suggest that these broadcast products could be used in quarantined counties. These products have never been used in Virginia, and may have negative impacts on ants native to the quarantined areas. The potential effects of these broadcast control products on non-target ant species were evaluated in field plots located in Virginia Beach, VA. Ant species present in the study plots were identified and quantified prior to treatment. After treatment, plots were sampled repeatedly for ant species at 24 hours, 72 hours, 7 days, 14 days, and each month thereafter for 1 year.