permaculture

[lbsaltzman@aol.com]

Here is yet another theory. I hope this gets solved.
 
http://www.latimes.com/news/science/la-sci-bees26apr26,0,896792.story/ 


Researchers link fungus to bee losses in U.S.
By Jia-Rui Chong and Thomas H. Maugh II
Times Staff Writers


5:06 PM PDT, April 25, 2007


A fungus that caused widespread loss of bee colonies in Europe and Asia may 
be playing a crucial role in the mysterious phenomenon known as Colony 
Collapse Disorder that is now wiping out bees across the U.S., University of 
California, San Francisco researchers said Wednesday.


Researchers have been struggling for months without success to explain the 
disorder, and the new findings represent the first solid evidence pointing to 
a potential cause.


But the results are "highly preliminary" and are from only a few hives from 
Le Grand in California's Merced County, UCSF biochemist Joe DeRisi said. "We 
don't want to give anybody the impression that this thing has been solved."


Other researchers said Wednesday that they too had found the fungus, a 
single-celled parasite called Nosema ceranae, in affected hives from around 
the country -- as well as in some hives that have continued to survive and 
live. Those researchers also have found two other fungi and a half-dozen 
viruses in the dead bees.


"N. ceranae" is "one of many pathogens" in the bees, said entomologist Diana 
Cox-Foster of Pennsylvania State University. "By itself, it is probably not 
the culprit . . . but it may be one of the key players."


Cox-Foster was one of the organizers of a meeting in Washington, D.C., on 
Monday and Tuesday where about 60 bee researchers gathered to discuss Colony 
Collapse Disorder.


"We still haven't ruled out other factors, such as pesticides or inadequate 
food resources following a drought," she said. "There are lots of stresses 
that these bees are experiencing," and it may be a combination of factors 
that is responsible.


Historically, bee losses are not unusual. Weather, pesticide exposures and 
infestations by pests, such as the Varroa mite, have wiped out significant 
numbers of colonies in the past, particularly in the 1960s and 1970s.


But the current loss is unprecedented. Beekeepers in 28 states, Canada and 
England have reported large losses. About a quarter of the estimated 2.4 
million colonies across the United States have been lost since last fall, 
said Jerry Hayes of the Florida Department of Agriculture and Consumer 
Services in Gainesville.


"These are remarkable and dramatic losses," said Hayes, who is also president 
of the Apiary Inspectors of America.


Besides a loss in honey production, commercial beehives are used to pollinate 
one-third of the country's agricultural crops, including apples, peaches, 
pears, nectarines, cherries, strawberries and pumpkins. Ninety percent of 
California's almond crop is dependent on bees, and a loss of commercial hives 
could be devastating.


"For the most part, they just disappeared," said Florida beekeeper Dave 
Hackenberg, who was among the first to note the losses. "The boxes were full 
of honey. That was the mysterious thing. Usually other bees will rob those 
hives out. But nothing had happened."


Researchers now believe that the foraging bees are too weak to return to 
their hives.


DeRisi and UCSF's Don Ganem, who normally look for the causes of human 
diseases, were brought into the bee search by virologist Evan W. Skowronski 
of the U.S. Army's Edgewood Chemical Biological Center in Aberdeen, Md.


Dr. Charles Wick of the center had used a new system of genetic analysis to 
identify pathogens in ground-up bee samples from California. He found several 
viruses, including members of a recently identified family called iflaviruses.


It is not known if these small, RNA-containing viruses, which infect the 
Varroa mite, are pathogenic to bees.


Skowronski forwarded the samples to DeRisi, who also found evidence of the 
viruses, along with genetic material from Nosema.


"There was a lot of stuff from Nosema, about 25 percent of the total," 
Skowronski said. "That meant there was more than there was bee RNA. That 
leads me to believe that the bee died from that particular pathogen."


If Nosema does play a role in Colony Collapse Disorder, there may be some 
hope for beekeepers.


A closely related parasite called Nosema apis, which also affects bees, can 
be controlled by the antibiotic fumagillin, and there is some evidence that 
it will work on N. ceranae as well.
 
 
-----Original Message-----
From: lfl@intrex.net
To: permaculture@lists.ibiblio.org
Sent: Tue, 24 Apr 2007 9:25 AM
Subject: [permaculture] [Fwd: [SANET-MG] requim for the noney bee]


-------- Original Message --------
Subject: [SANET-MG] requim for the noney bee
Date: Tue, 24 Apr 2007 11:46:31 -0400
From: jcummins <jcummins@UWO.CA>
To: SANET-MG@LISTS.IFAS.UFL.EDU

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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