Mobility, longevity and activity of chlorfenapyr in soils treated at a termiticidal rate

The mobility, longevity and termiticidal activity of chlorfenapyr applied to soils at the termiticidal labeled rate was evaluated for 30 months after treatment (MAT) in a greenhouse study.

There was little dissipation of chlorfenapyr in soil treated at the labeled rate for perimeter treatments for the prevention and control of termite infestations. Chlorfenapyr was detected in soil immediately below the initially treated soil in the packed soil columns. This was likely due to settling of soil. The treated soil remained toxic to subterranean termites in 3 and 7 day bioassays over the duration of the study. The treated soil displayed slow-acting properties regarding toxicity to termites. Trace amounts of chlorfenapyr were detected in the eluates of packed soil cones.

The commercial formulation of chlorfenapyr used in this study (21.45% concentrate diluted to 0.125% prior to application) killed 100% of the tested subterranean termites for at least 30 months.