Neonicotinoid insecticides (NIs) and their transformation products were detected in honey, pollen and
honey bees, (Apis mellifera) from hives located within 30 km of the City of Saskatoon, Saskatchewan,
Canada. Clothianidin and thiamethoxam were the most frequently detected NIs, found in 68 and 75% of
honey samples at mean concentrations of 8.2 and 17.2 ng g−1 wet mass, (wm), respectively. Clothianidin
was also found in >50% of samples of bees and pollen. Concentrations of clothianidin in bees exceed the
LD50 in 2 of 28 samples, while for other NIs concentrations were typically 10–100-fold less than the oral
LD50. Imidaclorpid was detected in ∼30% of samples of honey, but only 5% of pollen and concentrations
were