Occurrence of the White Soybean Cyst Nematode, , and the Soybean Cyst Nematode, in Korea.

Soybean cyst nematode (, SCN) is the most harmful pathogen of soybean ( (L.) Merr.) worldwide. In 2016, a new soybean-parasitic cyst nematode, (the white soybean cyst nematode) was found parasitizing the roots of soybean plants in Korea. To investigate the distribution and population density of , 943 soil samples were collected from soybean fields in all nine provinces in Korea in 2017 to 2018. Cyst nematodes were detected in 343 samples (36.4%) from eight of the nine provinces, except the island of Jeju province. Among the 343 samples, was found in 227 samples (66.2%), in 95 samples (27.7%), and 21 samples (6.1%) were infested with both and . Wide distribution of in soybean fields indicates that is an important cyst nematode species parasitizing soybean together with .