A quantitative weight of evidence (QWoE) methodology was used to assess higher-tier studies on the effects of imidacloprid (IMI) on honeybees. Assessment endpoints were population size and viability of commercially managed bees and quantity of hive products.
The overall weight of evidence indicates that there is minimal risk to honeybees from exposure to IMI from its use as a seed treatment. Exposures via dusts from currently used seed coatings present a de minimis [too trivial or minor to merit consideration] risk to honeybees when the route of exposure is via uptake in plants that are a source of pollen or nectar for honeybees.
There were few higher-tier observational (ecoepidemiological) studies conducted with IMI.
Considering all lines of evidence, the quality of the studies included in this analysis was variable, but the results of the studies were consistent and point to the same conclusion – that IMI had no adverse effects on viability of the honeybee colony.
Thus, the overall conclusion is that IMI, as currently used as a seed treatment and with good agricultural practices, does not present a significant risk to honeybees at the level of the colony.
The GLP aggregated and excerpted this article to reflect the diversity of news, opinion and analysis. Read full, original post: Quantitative weight of evidence assessment of higher-tier studies on the toxicity and risks of neonicotinoids in honeybees. 2. Imidacloprid