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From:
Peter Loring Borst <[log in to unmask]>
Reply To:
Informed Discussion of Beekeeping Issues and Bee Biology <[log in to unmask]>
Date:
Sat, 5 Mar 2016 19:43:58 -0500
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Whether Lundgren was punished for his work on neonics, is impossible to determine. The govt says no -- what else would they say? Meanwhile Vera Krischik has been working on this for almost 20 years:

> Imidacloprid, a chloronicotynol, works on a wider range of taxa than the more specific varieties of B. thuringiensis. Consequently, nontarget effects of imidacloprid may occur in a broad range of insect taxa. Sclar et al. (1998) showed nontarget effects of imidacloprid on the heteropteran O. tristicolor (White). Wallner et al. (1999) found that Phacelia tanacetifolia Bentham excrete 3–10 ppb of imidicloprid in the nectar after seed treatment with Gaucho ([AI] imidacloprid). 

> This concentration, however, had _no effect_ on behavior or survivorship of the honey bee, Apis mellifera L. When sucrose containing imidacloprid at concentrations >20 ppb was fed to honey bees, it caused a reduction in foraging behavior and induced changes in the dancing behavior that discouraged bees that were not fed imidacloprid-treated sucrose from foraging (Kirchner 1999) 

[Just how the authors knew that bees were "discouraged from foraging" -- I don't know.

Krischik published a study more recently, citing a funding source as: USDA SARE (00015590) grant "The role of imidacloprid systemic insecticide on colony collapse disorder of honey bees and decline of bumblebee pollinators", 2010. The resulting publication states:

> Field studies on the effects of lower concentrations of neonicotinyl residue in pollen and nectar, similar to that found in seed treatments, usually showed _no effects_ on colony health of honey bees and bumblebees.

> Honey bees exposed for 4 months to flowering canola grown from clothianidin-treated seed (maximum of 2.24 ppb in nectar and 2.59 ppb in pollen) showed _no differences_ in mortality, worker longevity, brood development, colony weight, and honey yields compare to controls [52]. 

> A study on queenright (containing the queen) colonies of B. terrestris for 4 weeks in the field near imidacloprid seed-treated sunflowers found _no difference_ in worker or queen production [51]

Source:
Scholer, J., & Krischik, V. (2014). Chronic exposure of imidacloprid and clothianidin reduce queen survival, foraging, and nectar storing in colonies of Bombus impatiens. PloS one, 9(3), e91573.

The study in question involved confining bumble bees to greenhouses and feeding them insecticide laced syrup. Not surprisingly, the bumble bees suffered. 

Work comparing native bees and honey bees has revealed several key points. 

1) in the real world bees forage on multiple sources, even when put in the vicinity of nectar bearing crops. 

2) the honey bee system of processing food reduces the effect of insecticides when compared to solitary and semi-social bees. Solitary bees feed nectar and pollen directly to developing larvae whereas honey bee larval food is preprocessed. 

What this means is that other non-honey bee species can not be reliably used for surrogates, and that controlled studies where toxic syrup is fed directly does not reflect the real world. 

Side note: On Krischik's website there is a publication listed:

Krischik, V, M Spivak, K Klyczek, K Mogen, J Wu, J Scholer. Effect of chronic exposure of imdacloprid in sugar syrup on honeybee colony health, PLOSONE  (in manuscript)

Near as I can tell, this was never published. Now as a scientist, I fully acknowledge that absence of proof can not be taken as proof of anything. However, they got a grant to show "The role of imidacloprid systemic insecticide on colony collapse disorder of honey bees and decline of bumblebee pollinators" and from their publication, it appears that they did not find such a role. No effect on field colonies; the predicted effect on captive commercial bumble bees fed tainted syrup.

PLB

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