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  1. #41
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    Sep 2009
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    Default Re: A possible explanation for CCD

    Might want to consider that bumbles react differently to neonics than honey bees.

    Zoology (Jena). 2012 Dec;115(6):365-71. doi: 10.1016/j.zool.2012.05.003. Epub 2012 Oct 6.
    Differential sensitivity of honey bees and bumble bees to a dietary insecticide (imidacloprid).
    Cresswell JE, Page CJ, Uygun MB, Holmbergh M, Li Y, Wheeler JG, Laycock I, Pook CJ, de Ibarra NH, Smirnoff N, Tyler CR.
    Source

    Biosciences, College of Life & Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter EX4 4QD, United Kingdom. j.e.cresswell@ex.ac.uk
    Abstract

    Currently, there is concern about declining bee populations and the sustainability of pollination services. One potential threat to bees is the unintended impact of systemic insecticides, which are ingested by bees in the nectar and pollen from flowers of treated crops. To establish whether imidacloprid, a systemic neonicotinoid and insect neurotoxin, harms individual bees when ingested at environmentally realistic levels, we exposed adult worker bumble bees, Bombus terrestris L. (Hymenoptera: Apidae), and honey bees, Apis mellifera L. (Hymenoptera: Apidae), to dietary imidacloprid in feeder syrup at dosages between 0.08 and 125μg l(-1). Honey bees showed no response to dietary imidacloprid on any variable that we measured (feeding, locomotion and longevity). In contrast, bumble bees progressively developed over time a dose-dependent reduction in feeding rate with declines of 10-30% in the environmentally relevant range of up to 10μg l(-1), but neither their locomotory activity nor longevity varied with diet. To explain their differential sensitivity, we speculate that honey bees are better pre-adapted than bumble bees to feed on nectars containing synthetic alkaloids, such as imidacloprid, by virtue of their ancestral adaptation to tropical nectars in which natural alkaloids are prevalent. We emphasise that our study does not suggest that honey bee colonies are invulnerable to dietary imidacloprid under field conditions, but our findings do raise new concern about the impact of agricultural neonicotinoids on wild bumble bee populations.

    Copyright © 2012 Elsevier GmbH. All rights reserved.

    PMID:
    23044068
    [PubMed - in process]

  2. #42
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    Default Re: A possible explanation for CCD

    And a recent Spanish study reports:

    J Econ Entomol. 2010 Dec;103(6):1964-71.
    Overview of pesticide residues in stored pollen and their potential effect on bee colony (Apis mellifera) losses in Spain.
    Bernal J, Garrido-Bailón E, Del Nozal MJ, González-Porto AV, Martín-Hernández R, Diego JC, Jiménez JJ, Bernal JL, Higes M.
    Source

    IU CINQUIMA, Analytical Chemistry Group, University of Valladolid, E-47071 Valladolid, Spain. pepinho@qa.uva.es
    Abstract

    In the last decade, an increase in honey bee (Apis mellifera L.) colony losses has been reported in several countries. The causes of this decline are still not clear. This study was set out to evaluate the pesticide residues in stored pollen from honey bee colonies and their possible impact on honey bee losses in Spain. In total, 1,021 professional apiaries were randomly selected. All pollen samples were subjected to multiresidue analysis by gas chromatography-mass spectrometry (MS) and liquid chromatography-MS; moreover, specific methods were applied for neonicotinoids and fipronil. A palynological analysis also was carried out to confirm the type of foraging crop. Pesticide residues were detected in 42% of samples collected in spring, and only in 31% of samples collected in autumn. Fluvalinate and chlorfenvinphos were the most frequently detected pesticides in the analyzed samples. Fipronil was detected in 3.7% of all the spring samples but never in autumn samples, and neonicotinoid residues were not detected. More than 47.8% of stored pollen samples belonged to wild vegetation, and sunflower (Heliantus spp.) pollen was only detected in 10.4% of the samples. A direct relation between pesticide residues found in stored pollen samples and colony losses was not evident accordingly to the obtained results. Further studies are necessary to determine the possible role of the most frequent and abundant pesticides (such as acaricides) and the synergism among them and with other pathogens more prevalent in Spain.

    PMID:
    21309214
    [PubMed - indexed for MEDLINE]

  3. #43
    Join Date
    Sep 2011
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    Reno, NV
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    Default Re: A possible explanation for CCD

    Camero, So is that saying Honey bees react differently or that Honey bees don't react? Reacting differently does not mean there is any better consequence. it could be the same effect for a different reason. no reaction. is a much better situation.
    Stand for what you believe, even if you stand alone.

  4. #44
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    Sep 2009
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    Millbury, MA, USA
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    Default Re: A possible explanation for CCD

    Quote Originally Posted by Daniel Y View Post
    Camero, So is that saying Honey bees react differently or that Honey bees don't react? Reacting differently does not mean there is any better consequence. it could be the same effect for a different reason. no reaction. is a much better situation.
    Here's the quote:
    Honey bees showed no response to dietary imidacloprid on any variable that we measured (feeding, locomotion and longevity).

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