Huh? Are you asking if there are methods like ls([ DIR ]) and dir([ DIR]) (both found in the documentation for Net::FTP). Or are you asking if there is a method that specifically gets the "latest" file? If the latter option, the question "what do you mean by latest?" comes to mind. Assuming you mean file that was most recently changed, you can use mdtm( FILE ) to find the modification time for the file in question.
That being said, care to elaborate? Will regular Perl file checks not work?
And you didn't even know bears could type.