Comment on "Neonicotinoid Residues in Wildflowers, A Potential Route of Chronic Exposure for Bees".

Many previous studies report nectar residues being consistently lower than pollen residues in the same plant species. This is also evident in our samples from the oilseed rape (OSR) crop, where 100% of pollen samples contained thiamethoxam, whereas only 53.9% of the nectar samples had detectable levels of this compound. However, as clearly explained in our manuscript, our wildflower nectar and pollen samples were hand collected from different subsets of plant species−because some species produce plentiful pollen but little nectar, and others vice versa. Since the samples are from different species and were sometimes pooled, it is not surprising that they differ in levels of contamination. However, it should be mentioned that frequency of detections for thiamethoxam in pollen and nectar collected from wildflowers growing in OSR margins were 58.1 and 20.8% respectively, showing a similar relative proportion to what was found for OSR pollen and nectar (see above).