Neonicotinoids as seed potato treatments to control wireworms.

A series of field trials were carried out from 2000 to 2003. Neonicotinoid insecticides applied as seed potato treatments at planting were tested to control wireworms in potato crops. Compounds were applied as drench or spray. Neonicotinoids tested were imidacloprid at rates of 35, 70, 88, and 175 g a.i.; thiamethoxam at 17.5, 35, 50, 70, and 140 g a.i.; and thiacloprid at 72 and 144 g a.i. per metric ton seed potatoes. Treatment with imidacloprid at 70 g/ton seed and thiamethoxam at 50 g/ton seed showed significant control of wireworms at harvest but thiacloprid showed insufficient protection. No phytotoxicity was recorded at harvest. Prospects and benefits of seed potato treatments with neonicotinoids are discussed, including lowering of the amount of insecticide needed for adequate protection.