Known Distribution of the Soybean Cyst Nematode, <i>Heterodera glycines</i> , in the United States and Canada Through 2023

The soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is a major yield-reducing pathogen of soybean ( Glycine max [L.] Merrill) in the United States and Canada, causing twice as much yield loss annually as any other pathogen. Reports of new discoveries of SCN in areas of the United States and Canada that grow the crop can lead to greater awareness of the pathogen and increased efforts to scout for the nematode. Beginning in January 2024, university nematologists, plant pathologists, and agronomists as well as government plant health officials in soybean-producing states in the United States and provinces in Canada were queried about the known distribution of the nematode. This publication contains an updated map of the known distribution of SCN in the United States and Canada through 2023 and a listing of counties and rural municipalities where the nematode initially was identified between 2000 and 2023. In total, there were 31 counties in 10 states in the United States plus three counties total in Manitoba and Ontario and 10 rural municipalities in Quebec, Canada, in which SCN was first discovered between 2020 and 2023. The results show that the distribution of SCN in the United States and Canada continues to expand, and sustained scouting for the presence of the pathogen is warranted to facilitate management to reduce soybean yield losses. [Formula: see text] Copyright © 2025 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .