Is the Jewel of the Bee Hive Affected by Neonicotinoids?

From the open access study "Assessment of Chronic Sublethal Effects of Imidacloprid on Honey Bee ColonyHealth".

  
"The major finding was the higher rates of queen replacement and resulting broodless periods during the late summer in colonies exposed to 20 and 100 μg/kg of imidacloprid, which led to weaker colonies going into the winter. These exposure regimes sublethally affected colony health and significantly reduced overwintering success. However, the question remains as to whether doses of 100 or even 20 μg/kg exposed for 12 continuous weeks realistically represent imidacloprid residues in bee-collected food under agriculture settings."

In a very old post, When sub-lethal really means very lethal I raised this very concern about queens. I have witnessed since the 70's a decline in the performance of queens. I remember a conversation between beekeepers of 40+ years experience about their dismay that since 2000 their queens no longer mate reliably. Due to 'shifting baselines' in expectations, newer beekeepers accept this as normal.

The report will probably be dismissed because of the possibility (it's not known) that the doses were unrealistic and lab fed  - but a queen lives for 3-5 years (compared to 5 weeks for a summer worker bee) and this trial was only over 12 weeks. Crucially, the queen must be constantly fed by worker bees to ensure she can lay more than her own body weight in eggs per day, thus any contaminated food will affect the queen more. For this simple reason I would not be surprised if the doses are under reported. We have no ability to measure to the last decimal point what affect these chemicals have on bees, but the over whelming evidence is that they are a very high risk. The slow pace of scientific understanding suits the chemical companies very well. If we wait for science to work out exactly what is going on, it will be too late.

What is sad from this report is that the bees know the queens are failing, and they are vainly trying to replace them. One day science will be similarly insightful.

UPDATE 1: Reanalysis of UK Food and Environment Agency study may provide first conclusive evidence that neonicotinoids pesticides are a key factor in bee decline, despite it originally being used to support the opposite view. Link to article

UPDATE 2: Dr. Heather Mattila, a honeybee biologist at Wellesley College. “When I started working with bees 18 years ago, we’d replace living queens every two years,” she recalls. “Now queens die after half a summer. Nobody is really clear on why.” from this time article