Megacopta cribraria (Hemiptera: Plataspidae) Population Dynamics in Soybeans as Influenced by Planting Date, Maturity Group, and Insecticide Use.

Since its unintentional introduction during 2009, Megacopta cribraria (F.) has spread rapidly throughout the southeastern United States, mainly feeding and reproducing on kudzu, Pueraria montana Loureiro (Merr.) variety lobata (Willdenow), and soybeans, Glycine max (L.) Merr. Megacopta cribraria has become a serious economic pest in soybeans, forcing growers to rely solely on insecticide applications to control this insect. The main objective of this study was to investigate if variation in planting date and maturity group of soybeans had an impact on management of M. cribraria populations. Three experimental fields were located in North Carolina (2) and South Carolina (1), and the tests replicated during 2012 and 2013. Treatments consisted of three planting dates, four maturity groups, and insecticide treated versus untreated, at each location. More M. cribraria were found in untreated early planted soybeans than late planted soybeans. Generally, maturity group did not influence population densities of M. cribraria. Yield was significantly influenced by the interaction between planting date and maturity group. There was a negative linear relationship between M. cribraria populations and soybean yield. Although early planted soybeans may avoid drought conditions and potentially large populations of defoliators, these fields may be at greater risk for infestation by M. cribraria.