Hi Medhat,

I've provided the citation below.
The researchers fed the Test colonies with eucalypt pollen patties spiked
with  2.6 pg/g Thiamethoxam (unspiked patties to the Control hives).  For
those of you unfamiliar with this concentration, it is the same as 0.0026
ppb--un unimaginably low dose--about 1/1000th of the level typically found
in canola pollen.

They then allowed those colonies to rear drones.  The drones were removed
upon eclosure and placed in cages of 30 ea and returned to their maternal
hives.  Drone survival 15-18 days later was measured.  It was highly
variable, but tended to be very low (mean ~15%) in the Test hives.

If such incredibly low doses of thiamethoxam did indeed cause such high
drone mortality, I'd suspect that Canadian beekeepers would have noticed it!

Journal of Invertebrate Pathology
Volume 159, November 2018, Pages 78-86
Synergistic effects of pathogen and pesticide exposure on honey bee (Apis
mellifera) survival and immunity
https://doi.org/10.1016/j.jip.2018.10.005
-- 
Randy Oliver
Grass Valley, CA
www.ScientificBeekeeping.com

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