Also you should all be subscribed to Alex Wild's blog if you're not already. Along with being a brilliant macro photographer I've come to know him as the voice of reason when it comes to a lot of the more controversial things going on in biology. In this case he writes.
It seems silly to me that we in the U.S. lack a national biodiversity survey program. That is, there’s no biology equivalent to USGS. Our knowledge of where species occur in our country is- and I’m really not kidding- a haphazard history of where collectors have gone on vacation. As a result some parts of the continent are basically black holes. Try finding a comprehensive list of the ants of Kentucky, for example. It doesn’t exist.