Ebbenga, Dominique2022-08-292022-08-292022-05https://hdl.handle.net/11299/241382University of Minnesota Ph.D. dissertation. May 2022. Major: Entomology. Advisor: William Hutchison. 1 computer file (PDF); vii, 94 pages.Japanese beetle, Popillia japonica Newman, is an invasive insect, native to Japan. The species was detected in the United States in New Jersey in 1916, and then first confirmed in Minnesota in 1968. Since the arrival of P. japonica, the beetle has become a major pest in turfgrass and several crop agroecosystems. Current research has focused on understanding the biology and ecology of this pest as it continues to spread and establish in new regions. This dissertation includes studies that were conducted from 2018-2021 to develop more efficient ways to monitor P. japonica and determine the damage potential in wine grapes. In 2018-2020, a comparison of weight and volume calibration methods was conducted in Minnesota and in addition, a comparison of monitoring systems was conducted to observe differences in trap type, lure age, and check interval. Results from these studies provided insight on how to reduce the time required to quantify and maintain equipment for beetle trap catches and should make facilitation of area-wide tracking of P. japonica populations more efficient. Additional trials were conducted to develop a degree-day model to help predict 10% adult P. japonica by trap catch. Results from this study produced a tool that can be used by growers and producers to forecast beetle phenology based on local or regional ambient air temperature change during the growing season. Finally, studies were conducted in 2020-2021 to determine the impact of adult P. japonica foliar feeding on fruit yield and quality of a popular Minnesota cold hardy wine grape variety ‘Frontenac’. Results from these studies indicated increased beetle feeding had a significant and negative impact on several fruit quality parameters. These studies will be useful additions to the integrated pest management (IPM) toolbox that growers and crop consultants can use to improve their management strategies for P. japonica.enThesis or Dissertation