Pittman, Elizabeth2022-12-192022-12-192022-12-19http://hdl.handle.net/10919/112950Threecornered alfalfa hopper, Spissistilus festinus (Say) (Hemiptera: Membracidae), is a ubiquitous pest of soybean that causes yield loss in certain scenarios. Plant lodging, and significant stand loss, from this insect has occurred in Virginia’s piedmont since at least 2017. There is a need to determine if chemical control (e.g., foliar and or seed applied insecticides) can be used to minimize plant injury and preserve yield. We hypothesized that control with insecticides will vary depending on infestation timing, which is not known, and foliar insecticides will provide the best control when applied at or near the time pests arrive. In 2021, we evaluated spray timings based on plant development and estimated infestation timings using yellow sticky traps and timed visual observations. We identified two population peaks potentially related to herbicide applications and small grain harvest. No insecticide application yielded higher than unsprayed plots and there was high variability within treatments.application/pdfenAttribution-NoDerivatives 4.0 InternationalMaster's projectThreecornered Alfalfa HopperSpissistilus festinussoybeandouble-crop