Until the last week, thrips infestations in cotton have been relatively mild. There is no question we are now beginning to see a peak in thrips numbers. It is common in Tennessee for this to occur in late May or the first week of June. Cotton at the 1st and 2nd true-leaf stage will be most sensitive and most likely to benefit from a foliar insecticide application such as Acephate/Orthene, Bidrin of Dimethoate. Yield responses to foliar insecticides applied at the third true leaf stage or later are uncommon, assuming that an insecticide seed treatment was used, even though the emerging leaves often still have that crumpled, ‘thripy’ look.

Below are some pictures of pristine, 2nd leaf cotton that I would NOT spray (first picture), and cotton I would definitely consider spraying given the increasing thrips numbers at this time (second picture). The second picture is not especially severe thrips injury but represents a threshold level of damage where treatment is typically recommended on 1st or 2nd leaf cotton.