Allen, you are correct on all counts.

Folk should not confuse the bioaccumulation that occurs with the
organochlorine insecticides (DDT, Chlordane) with the actions of the
current systemic pesticides.  Nor should they confuse the word systemic--it
means that plants transport the insecticide through their tissues, not that
the effect is systemic in insects nor humans.

One thing to keep in mind with the fear of neonics building up is that if
the pesticides did indeed build up in the soil and plants over time, there
would be no need for the farmers to keep buying them!  That would be a poor
business model for the manufacturers.

If a pesticide binds strongly to the soil, that also tends to indicate that
the plants would have a difficult time prying them loose.

In canola, after years of continuous application, clothianidin residues do
not appear to increase in nectar nor pollen.

As Mike says, it is likely much better for the environment and human health
for there to be residues of the neonics, than for there to be residues of
the previous classes of insecticides.

The other side of the story is that some plants apparently concentrate some
systemic pesticides under certain conditions (notably sunflowers).  Some
intriguing data on apple trees suggests that this may occur after foliar
application.

This accumulation is being carefully studied by researchers and the EPA.
 There are not yet any definitive answers, but additional research will
likely lead to revision of some of the labels.





-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html

Guidelines for posting to BEE-L can be found at:
http://honeybeeworld.com/bee-l/guidelines.htm