Hello: Maybe you should ask FAO or some other. The BAPHIQ told me the all the pest area basically is regulated by international organizement. If some country in the blask list would ike to be not in the blacklist, it wil need decades and process to prove. The pest area is pubic for international. (The Radopholus similis part of the regulation is exit at least 5 year as I have seen, so the APHIS office in Taiwan seems accept it? http://www.ait.org.tw/en/agriculture/aphis/ ) Occuring and existence may not be harmful to the temperate country, but it's still the pest. I only know that florida is a A-class Radopholus similis area, but other states? The export countries also could apply to be not the pest area for the import country while the pest status is not recogniszed by international process. And there are the program for host plants and its part from the registered and artificiallly sheild field growers. Basically speaking, the biosecurity zone is as province margin in China. and while tranporting through the provinces, there will need a phyto issued by origin county, but actually...... And in the U.S., Canada, Australia, it should be as the margin of states or provines. (some pest is limited in some county scale.) (I don't know if there are inspector on the border of state. But as I have reviewed, most U.S. online store only especially indicate that shipping to Canifornia need a permit.) Canada is free from Radopholus similis in the regulations. The whole North Europe is safe too. And though the Englands and Netherland have it, I still can buy most of the bulbs, corms, and tubers from them. (no adventitious root.) (no international weeds.) http://baphiq.gov.tw/public/Data/… Best Regards Su-Hong-Ciao Taiwan