Colony Suppression and Possible Colony Elimination of the Subterranean Termites and by Discontinuous Soil Treatment Using a Diluent of Fipronil Suspension Concentrate.

We assessed the efficacy of a discontinuous soil treatment using a diluent of fipronil suspension concentrate in controlling colonies of and . In-ground monitoring stations were installed at Isogi Park and Kindai University, and individual termites inhabiting the stations were collected for four or six years to determine the numbers and locations of colonies present in test areas before and after the discontinuous soil treatment. Microsatellite genotyping indicated that two and two colonies in the test area at Isogi Park and five colonies in the test area at Kindai University were active and that their territories fluctuated every year. One of the two colonies at Isogi Park and one of the five colonies at Kindai University were subjected to discontinuous soil treatments with fipronil and were strongly affected by the treatment at the colony level, resulting in the suppression and possible elimination of colonies. Termite activity of the fipronil-treated colony of was detected within one week after the discontinuous soil treatment and was not found for more than two years (28 months), while termite activity of the fipronil-treated colony of was detected within four days and three weeks after the discontinuous soil treatment and was not detected thereafter for three years. Fipronil residue analysis showed that workers of moved at least 28 m and that workers of moved 6 m from the treated soil locations for up to three weeks.