Western bean cutworm (Striacosta albicosta (Smith; Lepidoptera: Noctuidae)) and true armyworm (Mythimna unipuncta (Haworth; Lepidoptera: Noctuidae)) can cause significant injury to a variety of field crops in Ontario, resulting in economic losses. S. albicosta is a major pest of corn and dry edible beans in Ontario, whereas M. unipuncta is a sporadic pest of winter wheat, spring wheat, barley, and corn (OMAFRA, 2009). Management of these pests relies on insecticides and transgenics producing toxins from Bacillus thuringiensis (Bt); however, stewardship of the single Bt product, Vip3A (event MIR162, Syngenta Seeds, Inc.), capable of successful S. albicosta control is crucial for the continued use of this toxin. Furthermore, research is limited regarding M. unipuncta susceptibility to current management products, including Bt toxins (Smith et al., 2019). This research aims to 1) determine S. albicosta larval movement within fields, 2) determine S. albicosta overwintering success, and 3) modernize M. unipuncta economic thresholds. The first two objectives will be conducted in field trials to investigate S. albicosta larval movement and overwintering success within a field of Bt, non-Bt, and 10% refuge-in-a-bag. This knowledge is integral for developing sustainable pest management programs that can effectively control S. albicosta. Objective three will be a small plot experiment where M. unipuncta larvae are artificially infested to various densities at the boot, milk, and flowering stages of winter and spring wheat. Plots were treated with various insecticides to determine their effects on biomass, seed weight, and seed counts. Results of these studies will fill essential gaps in the current literature to help develop sustainable pest management procedures for S. albicosta and M. unipuncta to reduce crop loss and production costs.

Expected Values of this Project