We have a couple peanut thrips trials that were planted on 24 April on the UGA Bowen Farm in Tifton that are currently experiencing moderate thrips pressure. These trials have treatments that include phorate (Thimet) in-furrow, imidacloprid (Admire Pro or Velum Total) in-furrow, thiamethoxam seed treatment (CruiserMaxx Peanut) and an untreated check. Adult thrips and some immature thrips are present on all of the treatments. We have not finished counting the thrips samples, so I do not know yet about relative abundance by treatment.
Damage Rating: On a 0 to 10 scale with 0 being no damage and 10 being a dead plant, the range of mean values by treatment was from 2 to 4.8. Phorate and imidacloprid treated peanuts have significantly lower damage ratings than thiamethoxam seed treatment or the untreated check. There is an obvious amount of phorate injury where this insecticide was used (see picture below).
We are not seeing any terminal damage yet, but immature thrips are present and I expect to see terminal damage in the non-treated check by next week. This is the time I would probably pull the trigger on an acephate (Orthene) application on the non-treated check and seed treatment if this scenario were present in a commercial field. We do not know if the foliar application will pay for itself as the relationship between early season thrips damage and yield loss in peanut is not well understood. Nevertheless, if we are going to make a foliar spray it needs to be before we reach peak damage.