We began sampling cotton and peanut seedlings this week for thrips. We take cotton plants or peanut leaflets from field plots, rinse the adult and immature thrips into lab dishes, and count them under a scope.
We are at the beginning of the infestation and seeing just a few adults on plants. There are less than 1 adult per plant on cotton seedlings and less than one per leaflet in peanut. We see even fewer immatures, with one exception–in some cotton that was planted very early during the last week in April. Those plants have pretty high numbers of immaturesaround 20 per plant.
We are just beginning to see the visual symptoms of the feeding injury but not enough yet to do ratings. In general the infestation is a little behind compared to most years due to the cooler spring/early summer temperatures. But, I expect we will see more immatures next week and more injury.
Even though the infestation seems a little delayed, I would stay with our recommended treatment schedule. If a foliar application is needed, I would still target the early first true leaf stage. Treating when seedlings are in that stage has almost always given us the best resultsstay with the plan. We will begin providing weekly updates on thrips and other insect pests as the season progressesso stay tuned.