Toxicity ofFipronil in Mississippi Soil Types Against Reticulitermes jlavipes (Isoptera: Rhinotermitidae)

63 Three soils (a silt loam, loamy sand, sandy loam) found in Mississippi and pure silica sand were treated with fipronil and bioassayed using eastern subterranean termites, Reticulitermes jlavipes. Soils were treated with aqueous solutions ofTermidor (fipronil) at concentrations of 0, 0.12, 0.25,2.5, 5.0 and 20.0 ppm (wt AI: wt soil) that brought the soils to 15% moisture. Estimated lethal concentrations (ppm) required to kill 50% of termite workers within 96 h after placement on the soils were: 0.49 (sandy loam), 0.70 (sand), 4.21 (loamy sand), and 6.99 (silt loam). Termite mortality decreased with increases in organic matter content of the soils treated with fipronil.