This came over the transom. It is a MUST READ: --- Thought you might be interested in this nice summary of imidacloprid. You can view it at www.pesticide.org/imidacloprid.pdf The scientist who prepared it is Caroline Cox and ... she got the soil persistence data from the US Environmental Protection Agency registration information that was submitted by Bayer. It is interesting that the authorities know that imidacloprid can persist for over a year is that it is highly mobile in soil but did not give it a Restricted Use Classification. Sounds like economic reasons are more important than decisions based on science. allen http://www.internode.net/HoneyBee/Imidacloprid/