Field evaluation of label-rate broadcast treatment with baits for controlling the red imported fire ant, Solenopsis invicta (Hymenoptera: Formicidae)

The metaflumizone-containing bait Siesta™ is the newest bait developed to control the red imported fire ant (RIFA), Solenopsis invicta Buren. This study evaluated field performance of label-rate broadcast application of Siesta™ in comparison to that of the indoxacarb-containing bait Advion™ and hydramethylnon-containing bait Amdro®. Using metal probe sampling, hotdog sampling, and new mound counts, we measured the speed of RIFA control, level of foraging activity, and establishment of new colonies at 1, 3, 7, 14, 30, 60 and 90 d post-treatment. The presence of brood inside mounds was recorded on the last day. Within one week after treatment, Siesta™ and Advion™ treatments resulted in equally significant (P 95% and remained at that level over time, whereas Amdro® showed a typical performance curve and only reached >95% colony mortality after 30 d post treatment. During the entire trial period, significantly fewer (P < 0.05) new mounds appeared in Siesta™ or Advion™ plots (0.7 and 0.75 mound/plot, respectively) than in Amdro" (2 mounds/plot) and control plots (3 mounds/plot). Ultimately, label-rate broadcast treatment with Siesta™ is equally effective as Advion™ in providing a quicker and better control of fire ant colonies than Amdro'. The relationship and difference between the results from different sampling methods are discussed.