Effect of Planting Date and Maturity Group on Soybean Yield Response to Injury By the Kudzu Bug, Megacopta cribraria F. (Hemiptera: Plataspidae)

The kudzu bug, Megacopta cribraria (F.) is an invasive member of the family Plataspidae originating from Japan. Since its 2009 discovery in Georgia distribution has increased to 13 southeastern states. In the U.S. kudzu bug is bivoltine and has two developmental hosts, kudzu and soybean. We evaluated the yield response of soybean to kudzu bug feeding injury. The study contained four replicated trials over two years (2012, 2013) with four planting dates, consisting of split plots in a randomized complete block design with planting date as the whole plot (planted in Griffin, Tifton, Midville and Athens, GA). Soybeans were planted monthly from April to July. Maturity group 5 and 7 soybeans were used and a broad spectrum insecticide (lambda-cyhalothrin) was applied to randomly selected plots. Egg masses, nymphs, and adults were counted weekly to biweekly until soybeans reached maturity. Insecticide protected plots had consistently higher yields than unprotected plots. The yield response was greatest in April planted soybeans. Maturity group did not affect yield response in most comparisons except in the 2012 Griffin trial. This study indicates that early planted soybeans are at greater risk of yield loss from kudzu bug injury than later planted soybeans for double crop production.