Comparative efficacy of aerial and chemigation insecticide applications for managing western bean cutworm based on a two-year on-farm study

Application method and timing can strongly influence the efficacy and efficiency of insecticide treatments. The western bean cutworm (WBC), Striacosta albicosta, is a significant pest of corn that can cause severe damage to corn ears through larval feeding. In Nebraska, WBC management frequently relies on insecticide application; however, inadequate applications or ineffective insecticides can lead to control failures.Therefore, this study aims to determine the most effective method and insecticide for managing WBC in corn. Most corn growers apply insecticides by airplane targeting this pest, while some growers apply insecticides through the irrigation system, known as chemigation. In an on-farm research study over two growing seasons, bifenthrin and chlorantraniliprole were applied at the tasseling stage at their label rates 52.6 and 88 g AI/ha, respectively. Aerial applications were performed at 18.7 L/ha of carrier volume, while chemigation was applied at 2.1 ha-mm for chlorantraniliprole, and 5.15 ha-mm for bifenthrin. The efficacy of applied insecticides was evaluated by assessing WBC crop injury. At 28 days after treatment, 20 ears per plot were collected and assessed for the presence of WBC larvae and the amount of feeding injury (cm²). Chlorantraniliprole treatments performed best across both application methods, reducing ear feeding injury, while bifenthrin provided moderate control. There was no significant difference in insecticide performance between application methods for preventing yield loss. These findings highlight the efficacy of chlorantraniliprole in reducing feeding injury and suggest that the selection of the application method may be more flexible without causing yield loss.