Critical time period in flowering cotton that yield loss due to tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), occurs

The tarnished plant bug is a major pest of cotton in the Mid-South. Insecticides are the main form of control for this pest, and numerous applications are required during a growing season to control the tarnished plant bug. Little information exists about when to terminate insecticide applications targeting tarnished plant bugs in cotton. Numerous sprays with tank mixtures of high rates of organophosphates and pyrethroids are made late in the season to protect a small percentage of the overall yield.  Experiments were conducted at the Mississippi State University Delta Research and Extension Center to determine the impact of tarnished plant bug infestation timings on cotton yields. Two separate planting dates were utilized to determine the  weeks of flowering that tarnished plant bugs can cause significant yield losses. There was not a significant planting date by treatment interaction, so the data were combined across planting dates. The first four weeks of flowering were the most critical for tarnished plant bug control and this is when the greatest yield losses occurred. However, when insecticide applications were terminated after the fourth week of flowering, there was no significant loss in yield when compared to the season long control.