[FLPERMACULTURE] Requiem for the Honeybee

Tue Apr 24 12:48:36 PDT 2007

------------------------------ Original Message ------------------------------
Subject: requim for the honey bee
From:    "jcummins" <jcummins at UWO.CA>
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24 April 2007
Requiem for the Honeybee
Neoniccotinoid insecticides used in seed dressing may be responsible for  the
collapse of honeybee colonies
Prof. Joe Cummins

Neonicotinoid insecticides are harmful to the honeybee

There has been a great deal of concern over the decline of the honeybee 
across the US, Europe and Australia [1] (The Mystery of Disappearing 
Honeybees, this series). The United States National Research Council  (USNRC)
Committee of the Status of Pollinators in North America report  [2] focused on
the impact of parasites, fungi, bacteria and viruses, but  did not pay much
attention on the impact of pesticides and genetically  modified (GM) crops,
which may have lethal or sub-lethal effects on the  bee’s behaviour or
resistance to infection. There have been strong  responses to the report. Any
suggestion that GM crops and pesticides may  be causing the decline of
honeybees is met with heated denial from the  proponents.

Certainly, honeybees are declining both in areas where GM crops are  widely
grown, and in other areas where GM crops are released in small  test plots. Is
there a common thread that links both areas? Yes there  is, the universal use
of systemic pesticide seed dressing in GM crops  and conventional crops; in
particular, the widespread application of a  relatively new class of systemic
insecticides - the neonicotinoids -  that are highly toxic to insects
including bees at very low concentrations. Systemic pesticide seed dressings
protect the newly  sprouted seed at a vulnerable time in the plant’s
development. Seed  dressings include systemic insecticides and fungicides,
which often act  synergistically in controlling early seedling pests.

The neonicotinoid insecticides include imidacloprid, thiamethoxam, 
clothianidin, and several others. Imidacloprid is used extensively in  seed
dressing for field and horticultural crops, and particularly for  maize,
sunflower and rapeseed (canola). Imidacloprid was detected in  soils, plant
tissues and pollen using HPLC coupled to a mass spectrometer. The levels of
the insecticide found in pollen suggested  probable delirious effects on
honeybees [3]. For several years since  2000, French and Italian beekeepers
have been noticing that imidacloprid  is lethal to bees, and the insecticide
is suspected to be causing the  decline of hive populations by affecting the
bee’s orientation and  ability to return to the hive.

Confused and disoriented bees

A team of scientist led by the National Institute of Beekeeping in  Bologna,
Italy, found that pollen obtained from seeds dressed with  imidacloprid
contains significant levels of the insesticide, and suggested that the
polluted pollen was one of the main causes of honeybee colony collapse [4].
Analysis of maize and sunflower crops  originating from seeds dressed with
imidacloprid suggest that large  amounts of the insecticide will be carried
back to honey bee colonies  [5]. Sub-lethal doses of imidacloprid in sucrose
solution affected  homing and foraging activity of honeybees. Bees fed with
500 or 1 000  ppb (parts per billion) of the insecticide in sucrose solutions
failed  to return to the hive and disappeared altogether, while bees that had 
imbibed 100 ppb solutions were delayed for 24 h compared with controls.  [6].
Imidacloprid in sucrose solution fed to the bees in the laboratory  impaired
their communication for a few hours [7]. Sub-lethal doses of  imidacloprid in
laboratory and field experiment decreased flight activity and olfactory
discrimination, and olfactory learning performance was impaired [8]..

Bayer corporation scientists reported that neither honeybees exposed to 
imidacloprid in sunflower seeds dressed with the insecticide [9] nor  maize
seeds dressed with the insecticide or released from the seeds  during planting
[10] were detrimental to honeybees. The Bayer studies  did not deal with
sub-lethal behaviour of intoxicated bees. An independent study found that
imidacloprid was released to the environment from treated maize seeds during
seed planting [11]. Bayer  eco-toxicologists directed harsh criticisms at
reports showing lethal or  sub-lethal toxic effects of imidicloprid seed
dressing and concluded  that imidacloprid does not pose any significant risk
to honeybees in the  field [12], without, however, disproving the findings. It
is simply yet  another case of the anti-precaution principle being applied
[13] (Use  and Abuse of the Precautionary Principle, ISIS News 6)Turning to GM
crops such as maize, canola, cotton and soybean it is  clear that all of these
GM crops, with or without Bt genes, use seeds  most of which are coated with
neonicotinoid pesticides highly toxic to  honey bees. For example, Herculex
maize with Bt genes to control rootworm, like Yieldgard corn borer resistant
maize, is planted with  seeds dressed with a neonicotinoid insecticide and a
fungicide.

Furthermore, the GM planting requires setting aside plots of non-GM  maize
making up 20 percent of the planted area as a “refuge” to
discourage the evolution of resistant insects. But the “refuge” is  sprayed
with neonicotinoid pesticide to protect its yield [14], and is  more like a
death camp for insects. Monsanto’s US Patent 6,660,690  provides for coating
GM seeds with chemical pesticides [15].

Toxicology known

The toxicology of neonicotinoid insecticides is well known. The insecticides
are inhibitors of acetycholine receptors (i.e., they are  nerve poisons). They
have low toxicity for mammals, birds and fish, and  are used to control fleas
on dogs and cats [16]. The nicotinic acetylcholine receptor gene family of the
honeybee has been studied; it  has 11 subunit members, a larger number than
the fruit fly or mosquito.  The genes for the subunits employ alternatively
spliced transcripts to  increase receptor diversity, and the messenger RNAs
are edited to  replace specific A bases with I bases. Information on the
receptor  should allow for development of insecticides that are not harmful to
 bees [17].
In conclusion, the US NRC Committee did not deal with the heated debate  over
neonicotinoid pesticides and honeybee decline. Instead, that it  seemed to
suffer from tunnel vision and to be overcautious about matters  that threaten
large corporations.

We urgently need a thoroughly independent committee to consider the full 
range of factors that may be contributing to the decline of bees,  including
pesticides, GM crops and electronic devices, before the bees  become extinct.

References
1. Ho MW and Cummins J. The mystery of disappearing honeybees. Science  in
Society 34 (in press)
2. Committee on the Status of Pollinators in North America American  National
Research Council Status of Pollinators in North America 2006 
ISBN:978-0-309-10289-6
3. Bonmatin JM, Moineau I, Charvet R, Fleche C, Colin ME and Bengsch ER.  A
LC/APCI-MS/MS method for analysis of imidacloprid in soils, in plants,  and in
pollens. Anal Chem. 2003 May 1;75(9):2027-33.
4. Bonmatin JM, Marchand PA, Charvet R, Moineau I, Bengsch ER and Colin  ME.
Quantification of imidacloprid uptake in maize crops. J Agric Food  Chem. 2005
Jun 29;53(13):5336-41.
5. Rortaisa A, Arnolda G, Halmbm M and Touffet-Briensb F. Modes of  honeybees
exposure to systemic insecticides: estimated amounts of  contaminated pollen
and nectar consumed by different categories of bees  Apidologie 2005, 36 ,
71-83
6. Bortolotti L, Monanari R, Marcelino J and Porrini P. Effects of  sub-lethal
imidacloprid doses on the homing rate and foraging activity  of honey bees.
Bulletin of Insectology 2003, 56 (1),: 63-67
7. Medrzycki P, Monntanari L, Bortolotti L, Sabatinin S and Maini S.  Effects
of imidacloprid administered in sub-lethal doses on honey bee  behaviour.
Laboratory tests. Bulletin of Insectology 2003, 56 (1): 59-62 8. Thompson H.
Behavior effects of pesticides in bees-their potential  for use in risk
assessmernt. Ecotoxicology 2003,12,317-30
9. Schmuck R, Schoning R, Stork A and Schramel O. Risk posed to
honeybees (Apis mellifera L, Hymenoptera) by an imidacloprid seed  dressing of
sunflowers. Pest Manag Sci. 2001, 57(3), 225-38.
10. Schnier H, Wenig G, Laubert F, Simon V and Schmuck R. Honey bee  safety of
imidacloprid corn seed treatment Bulletin of Insectology 2003,  56 (1), 73-75.
11. Greatti M, Sabattini A, Barbatiini R, Rossi S and Stravisi A. Risk  of
environmental contamination by the active ingredient imidacloprid  used for
corn seed dressing. Preliminary results. Bulletin of
Insectology 2003, 56 (1), 69-72.
12. Maus C, Cure G and Schmuck R. Safety of imidacloprid seed dressings  to
honey bees:
a comprehensive overview and compilation of the current state of
knowledge. Bulletin of Insectology 2003, 56 (1), 51-57.
13. AgriGold Hybrids Insect Resistance management 2007
http://www.agrigold.com/index.cfm?pageId=35
14. Saunders PT. Use and abuse of the precautionary principle. ISIS 
submission to US Advisory Committee on International Economic Policy  Biotech.
Working Group 13 July, 2000, also ISIS News 6, September 2000, 
http://www.i-sis.org.uk/prec.php
15. Asrar J and Kohn F. Seed treatment with combinations of
insecticides. 2003 United States Patent 6,660,690.
16. Tomizawa M and Casida JE. Neonicotinoid insecticide toxicology: 
mechanisms of selective action. Annu Rev Pharmacol Toxicol. 2005; 45, 247-68
17. Jones AK, Raymond-Delpech V, Thany SH, Gauthier M and Sattelle DB.  The
nicotinic acetylcholine receptor gene family of the honey bee, Apis 
mellifera. Genome Res. 2006, 16(11), 1422-30.

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