According to a prosecution indictment, Chinese researcher Jian Yunqing, currently at the University of Michigan, and her boyfriend Liu Zunrong, who is conducting biological research at Zhejiang University, are accused of conspiring to illegally smuggle pathogens and making false statements, engaging in activities inconsistent with their visa purposes.

Liu was caught in July 2024 upon entry into the US with wheat stem rust fungus in his luggage, and his inconsistent statements led to his denial of entry. Professor Zilfoss from Michigan State University stated, "Wheat stem rust fungus is a globally widespread pathogen that can infect wheat, corn, and other grains, producing toxins and mycotoxins as well."

After the incident, Republican lawmakers accused China of attempting to wage biological warfare against the US, labeling it as agricultural terrorism. The New York Post noted that the wheat stem rust fungus already exists within the US, as several research institutions acquire strains for studies on plant pests and diseases.

Professor Zilfoss emphasized that importing strains may be necessary sometimes, but it must be done through the USDA Animal and Plant Health Inspection Service to ensure proper procedures and to destroy the strains afterward under quarantine. The concern is whether the strains involved in Liu and Jian's alleged smuggling were modified in China to enhance their resistance to drugs. If so, and they entered US farms, American agriculture could face devastating consequences.