Effect of Using Early-Planted Soybeans As a Trap Crop for Megacopta cribraria in Commercial Soybeans

Since its introduction in 2009, Megacopta cribraria has been managed primarily by whole-field applications of broad-spectrum insecticides in soybeans. This study investigated using an early-planted soybean strip around a field perimeter as a trap crop to manage M. cribraria. The rationale behind this proposal is based on two premises: 1) M. cribraria spatially aggregates in field borders, and 2) higher infestations of M. cribraria have been recorded in early-planted soybeans. Six North Carolina commercial soybean fields were selected during 2014 and were planted with a ~9.5m strip of earlier planted soybeans encompassing timely-planted soybeans in the interior and were compared to six fields without a trap crop. Based on localized Moran’s I statistics, M. cribraria first aggregated and established in the trap crop with fewer M. cribraria that established in the middle of these fields. In contrast, M. cribraria aggregations were found in the middle of fields with no trap crop. Early-planted soybeans used as a trap crop could be a feasible strategy for managing M. cribraria in commercial soybean fields. Other tactics, such as border sprays, could accompany this proposed strategy to improve M. cribraria control at the trap crop and reduce the amount of active ingredient per hectare.