Systems Approach to Evaluate Tarnished Plant Bug (Hemiptera: Miridae) Management Practices in Virginia and North Carolina Cotton.

Economically damaging infestations of Lygus lineolaris (Palisot de Beauvois), tarnished plant bug, were sporadic in Virginia and North Carolina cotton before 2010. Given the sudden rise of L. lineolaris as an economic pest in these states, regionally specific management practices (i.e., chemical and cultural control) are needed to help producers protect yield potential while minimizing input costs. Field experiments were conducted in Virginia and North Carolina in 2018 and 2019 to 1) determine the effects of various management practices on L. lineolaris density, plant injury (i.e., square retention, internal boll injury), and lint yield, 2) calculate the economic trade-offs between integrated pest management (IPM) systems approach and current management practices for L. lineolaris in these states, and 3) evaluate economic benefits associated with various sampling thresholds. Lygus lineolaris populations peaked mid-season (i.e., August) during cotton flowering in both states. Weekly scouting and applying foliar insecticides when the current University Extension recommended economic threshold was reached was the most critical management treatment in maximizing economic returns. Additional costs among various IPM practices did not translate into significant yield protection and economic gains. Moreover, there were additional economic benefits associated with protecting glabrous and longer maturing varieties in Virginia. Lygus lineolaris density varied significantly between states; therefore, management recommendations should be modified based on the growing region. Results from this study will be used to create an IPM strategy to help cotton producers effectively manage this insect pest in the Southeast.