In my area I have never seen or heard of testing occuring in the lower ranks, mostly because I race and fraternize with riders in the lower ranks. Maybe the 1's and 2's are tested... according to pedals they are, and I would imagine when it happens it's more common at national and regional titles and higher profile races.
In my local bike shop I was recently chatting with their Shimano rep and he travels to Italy quite a bit. He was telling me some of he local amateurs are stronger than the pros where he was as they are doped to the gills and testing is almost non-existent.
It's sorry that some people immediately assume you are asking if you should dope, not that you simply have a curiosity whether testing occurs or not. Personally speaking it's none of my business if ya want to dope (but if u find some let me know /img/vbsmilies/smilies/wink.gif ).