Utilization of Imidacloprid to Control Thrips in Peanut in North Carolina

Tobacco thrips (Frankliniella fusca Hinds) is an important pest in peanut (Arachis hypogaea L.) in North Carolina and injury from this insect can lower yield. Research was conducted from 2012 through 2014 in North Carolina to compare visible injury from tobacco thrips feeding and peanut yield when acephate, imidacloprid, and phorate were applied alone in the seed furrow at planting or followed by acephate applied postemergence 3 weeks after planting. In a second experiment conducted during the same time period, a commercial liquid formulation of Bradyrhizobia inoculant was applied alone or with imidacloprid in fields with and without plantings of peanut in recent years. Peanut injury from tobacco thrips feeding was reduced by acephate, imidacloprid, and phorate applied in the seed furrow at planting compared with non-treated peanut. Acephate applied 3 weeks after planting generally reduced injury from thrips. Pod yield was greater when imidacloprid was applied compared with yield for the non-treated control or when acephate was applied in the seed furrow. Pod yield was similar regardless of in-furrow treatment when acephate was applied postemergence. Thrips control by imidacloprid was not affected by Bradyrhizobia inoculant, and imidacloprid did not negatively affect efficacy of Bradyrhizobia inoculant regardless of previous field history. These data indicate that imidacloprid protects peanut as well as or more effectively than the systemic insecticides acephate and phorate and that imidacloprid is compatible with Bradyrhizobia inoculant.