So your little make believe story is suppose to prove what? You answered your own question, they don't pay taxes. When they are doing farm work 99% of the time they are short term contractors and therefore no with holdings. They don't even file 1099's on them.
It simply amazes me the amount of experts on issues like illegal immigration that exists on threads like this. You must travel a lot to know that noone in this country who employs illegals or tracks the employment of same is involved in collecting taxes on their pay. Funny how the states are knowingly allowing farmers and others to get away without paying taxes, or knowingly allowing illegals to get away without paying taxes. Yes, the IRS would not ever be interested in collecting taxes from these employees or employers. So, tell me, o’great one, where are your sources to back up what you say I did not see with my own eyes?