> Neonics are systemic.  That means application will result in their infiltration of all plant materials, blooms, pollen, stems, roots....all of it.

The chemical is differentially expressed in leaves, pollen and nectar. This should not surprise us. In nicotine producing plants the nectar has very low concentrations of nicotine. It would be maladaptive for a plant to poison its pollinators. Plants produce poisons mainly in the leaves to kill predators. Neonics are similarly found mainly in the leaves which are attacked by plant pests, and hardly at all in the nectar and pollen.

> Via the plant sap transport neonicotinoids are translocated to different plant parts. In general, the few reported residue levels of neonicotinoids in nectar (average of 2 ug kg-1) and pollen (average of 3 ug kg-1) were below the acute and chronic toxicity levels; however, there is a lack of reliable data as analyses are performed near the detection limit. Similarly, also the levels in bee-collected pollen, in bees and bee products were low. ... Many lethal and sublethal effects of neonicotinoid insecticides on bees have been described in laboratory studies, however, no effects were observed in field studies with field-realistic dosages.

Blacquiere, T., Smagghe, G., Van Gestel, C. A., & Mommaerts, V. (2012). Neonicotinoids in bees: a review on concentrations, side-effects and risk assessment. Ecotoxicology, 21(4), 973-992.

             ***********************************************
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