Impact of soybean planting date, maturity group, and insecticide use on Megacopta cribraria

Megacopta cribraria (F.) is an invasive species that feeds on soybeans. Few management tactics are known for this pest in soybeans. A study investigated the impact of planting date, maturity group, and insecticide use on M. cribraria abundance and yield in soybeans. Four soybean maturity groups were planted in April, May and June at two locations in southern NC in 2012. Each maturity group within a planting date was split into insecticide-treated and untreated plots. Two June plantings were made, one with conventional till and a second in no-till behind wheat. Megacopta cribraria densities fluctuated across planting dates and maturity groups. In general, densities were higher in earlier planted and earlier maturing soybeans when comparing insecticide-treated and untreated plots. For yield, there was no interaction with insecticide treatment and planting date or maturity group. Yields were affected by maturity group and planting date alone in one location and in combination in another. There was no interaction between insecticide treatment and maturity group or planting date. Overwintering populations migrating to early-planted soybeans might have influenced adult densities. Based on our initial findings planting date, maturity group and insecticide treatment have the potential to influence both M. cribraria abundance and soybean yield.