Effects of maximum residue limit of triflumezopyrim exposure on fitness of the red imported fire ant Solenopsis invicta

Abstract

The impact of exposure to free feeding concentrations of triflumezopyrim to the red imported fire ant, Solenopsis invicta, in maximum residue tolerances for 56 days was investigated to understand whether triflumezopyrim, a novel neonicotinoid, poses unacceptable risks to the environment. Our results demonstrated that neither 0.5 μg/ml nor 0.2 μg/ml triflumezopyrim have a significant impact on the growth of the S. invicta colony and their food consumption (sugar water and locusts) during the length of treatment. While both 0.5 μg/ml and 0.2 μg/ml triflumezopyrim improved the grasping ability of S. invicta, and 0.5 μg/ml not 0.2 μg/ml triflumezopyrim increased their rate of locomotion. In addition, although 0.5 μg/ml and 0.2 μg/ml triflumezopyrim increased their individual aggressiveness index, the probability of the survival of S. invicta was not impacted by triflumezopyrim treatments in aggressive group encounters. This study suggests that triflumezopyrim did not have a negative impact on the fitness of S. invicta at 0.5 μg/ml and 0.2 μg/ml exposures.