This is entirely out of curiosity, not the desire to have a permit.
Where exactly is the list for animals that require a PPQ 526? I know that covers most insects, but I was curious which ones. Can somebody give me a link to a document, web page, or PDF where I can find the list? Thanks.
There is no list. It's entirely at the discretion of the Secretary of Agriculture's interpretation of the statute. California, Florida, and some other states maintain lists for their own Agriculture Departments; but the federal government, as far as I know, does not. That is not to say the feds maintain no lists—they do—for things like butterflies. There is simply no exclusive, comprehensive public list at the national level.
That said, the high-level list Subverted posted does show "Family Formicidae," so evidently the Secretary believes all ants are very high risk organisms.
I am very sad to report that I accidentally burnt my toast while typing this response