I would be interested to know if anyone has data on the movement of the
insecticide imidacloprid into nectar and its subsequent effect on bees.
 
Imidacloprid is a new insecticide that is making rapid inroads in alot of
crops primarily for control of sap-sucking homoptera (e.g., whiteflies,
aphids) and Colorado potato beetle.  It is sold under trade names such as
Admire, Provado, Marathon, and Merit in the US, with almost all applications
as a soil applied treatment for systemic uptake.
 
The reason I am asking is that I have heard a rumor that when applied in
greenhouses it is adversely affecting bumblebees.  Frankly I am surprised at
that rumor since 1) I did not think that much would be trnslocated to the
nectar and 2) no other Hymenoptera (primarily sawflies) that I have seen
appear to be affected by imidacloprid.  (It does have some limit to its
range of effectiveness; for example, spider mites and caterpillars are note
controlled by it.)
 
Although the rumor pertained to bumblebees, I am asking a honeybee group as
the latter are related species that are more closely researched and
observed.  My interest is related to the fact that imidacloprid soil
treatments are increasingly rapidly and supplanting many formerly used
foliar spray treatments of various insecticides.
 
Whitney Cranshaw
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