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A possible explanation for CCD

17K views 43 replies 13 participants last post by  camero7 
#1 ·
Some studies have reported that summer bees rather than winter bees were found in colonies going into the winter. The difference is in the smaller fat reserves, leaving summer bees with much shorter lifespans.
When the fat reserve is used up, a bee leaves the colony to die away from the hive.
Lots of bees leaving at the same time leave behind an empty hive, the beekeeper calls it CCD or Marie Celeste or dwindling disease.

The trigger for winter bee production in a healthy colony is the shortening of daylength after the summer solstice, June 21st.
Depending on your type of bee, winter bee production should commence soon or slightly later after that.


If the colony is under the influence of neurotoxins, like neonicotinoids, the bees might not be able to perceive the change of daylight and continue production of summer bees.

It has already been proven that neonicotinoids reduce the memory of bees in field studies (reutrn rate of foragers) and in the lab (training experiments).

A compromised memory would make perception of daylight changes impossible, and as many colonies are exposed to neonics at the critical time of year for winter bee procuction, we should look into this possibility more closely.


sources of neonics that could therefore be responsible for CCD:

@ fields of corn/maize
@ flowering trees like lime trees on golf courses and in parks, where the lawn/turf has been treated with the pesticides
@ other treated crops flowering around midsummer and after
@ contaminated water (runoff) that bees collect for brood rearing


Comments?
 
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#4 ·
The seeming lack of body reserves has repeatedly been mentioned in studies I have read over the years, but is usually attributed to other factors like varroa or malnutrition.
e. g. here:
Adult bees, which are infested by V. destructor as pupae, do not fully develop physiological features typical of long-lived winter bees compared with non-infested workers [6]–[8], making it unlikely for them to survive until spring and contribute to the build-up of the colony in early spring [2]. To date, however, the relation between the lifespan of individual bees and colony losses for different levels of V. destructor infestation has not been tested.
http://www.plosone.org/article/info:doi/10.1371/journal.pone.0036285
There are other quotes, but it would take me a while to find them again.

I am proposing the effects of neonics on the ability of bees to determine seasons as an alternative explanation.
 
#3 ·
A compromised memory would make perception of daylight changes impossible
This is a very big assumption that is probably untenable. Memory has nothing to do with the innate response to shortening day length. Responses to day length are usually triggered by the decrease/increase of chemical cues that cross a pre-set threshold causing up/down regulation of different genes that then, ultimately, act to change behavior. It is the exposure to light (or specific wavelengths) that either breaks down the chemical cues or aids in the synthesis of these cues. Bees don't "remember" how long the previous day was like they remember the timing and source of a resource.

I don't really know how bees translate day length into action but I do know that changes to day length affect insects in general at the hormonal level--allowing the establishment of circadian rhythms and the triggering of overwintering strategies. Often, when it comes to overwintering strategies, the strategy is in response to the exposure of a previous generation (I would guess not in bees, though, as only the queen lays eggs).
 
#5 ·
This is a very big assumption that is probably untenable. Memory has nothing to do with the innate response to shortening day length. Responses to day length are usually triggered by the decrease/increase of chemical cues that cross a pre-set threshold causing up/down regulation of different genes that then, ultimately, act to change behavior. It is the exposure to light (or specific wavelengths) that either breaks down the chemical cues or aids in the synthesis of these cues. Bees don't "remember" how long the previous day was like they remember the timing and source of a resource.

...
It is a theory and it needs testing, of course.

That shouldn't stop us from debating it here, adding our own observations.

Daylight perception is based on chemical reactions, so is memory.
Add unnatural chemicals and the whole system can be upset, possibly cancelling out natural triggers.
 
#6 ·
"Memory," in ethology, usually refers to a form of mental recall of past individual experience. The only bees that would live long enough to remember a past shortening of day length would be queens.

The lack of fat reserves that may contribute to losses due to Varroa usually leaves dead bees in the hives. CCD is characterized by a disappearance of bees. The idea that pesticides may interfere with bees' instinctive behaviors at different times of the year is worth investigating, but I wonder if the symptoms here are really consistent with CCD.
 
#7 ·
I doubt that you will see all of the symptoms that define CCD, such as no wax moths or robbing in dead hives. I am sure that there is some effect, but Hackenberg showed that CCD was a pathogen by irradiating half the dead hives in a group, then installing bees in all. The irradiated hives thrived, non-irradiated hives died.

Game over, please try again.

Crazy Roland
 
#8 ·
I doubt that you will see all of the symptoms that define CCD, such as no wax moths or robbing in dead hives. I am sure that there is some effect, but Hackenberg showed that CCD was a pathogen by irradiating half the dead hives in a group, then installing bees in all. The irradiated hives thrived, non-irradiated hives died.
The Hackenberg irradiation story is from 2007.

If it was effective then everybody would be doing it by now ...
 
#12 ·
Sromness - you do not "cleanse' all hive bodies every season? Hmmmmm.... oh well. Maybe the sucessfull do and just don't talk about it.
Just to clarify:

I have never had a disease problem or CCD in any of my hives.
I scrape boxes clean between use, that's all that I need to do, as I live in a disease free area where no pesticides are used, so my bees are extremely healthy.

I am addressing the problem of CCD in a general way, and after studying it for a long time I am certain that neonicotinoids are the cause.

The problem has always been, how to explain the sudden disappearance of bees during the winter months.
A friend of mine living in an agricultural area who has his bees close to home, observed them leaving the hives and not returning. That was at the onset of winter. The dwindling of his previously strong colonies lasted for about 10 days, and he was left with nearly empty boxes - typical of CCD.
And yes, he had treated and checked for varroa.


My theory, that neonics comporomise the bees' system of recognizing the change of season, would explain it in a very straight forward way.

It also explains other related phenomena, like the continued brood rearing very late in the season, which seems to precede CCD.
 
#33 ·
Interesting - they have CCD in varroa-free area? That against believe that varroa somehow involved in CCD. I did not know that irradiation prevents CCD. It sounded complicated,but in reality - most food in supermarkets are irradiated including strawberries etc. They have gigantic "facilitiesy" with usually cobalt-60 radioactive source and pass through the whole containers... it would not be difficult to irradiate beekeeping hardware if it will solve the issue.
 
#18 ·
Stromness: So you are contending that the only possible variable between your hives and your friends is exposure to Neonics even though you have already conceded that they were in an entirely different forage area presumably exposed to different nectar and pollen flows. How about other climactic conditions and specific location variables such as water sources, wind and sun exposure? Are all beekeeping equipment, methods and manipulations identical between your hives and your friends? And let's not so lightly dismiss varroa and the related viruses that they are known to spread. Tell us about you and your friends testing methods and results? Are you aware that there is no more classic sign of varroa mite stressed hives in collapse than seeing far more eggs and open brood than the reduced hive population can possibly care for? Tell us the body of experience that you and your friend (whose observations are a large part of your evidence) actually have. How many hives, how many years? Have either of you had much if any experience with bees prior to the introduction of Neonics? One final question. If I were to take the time to read through your 60+ posts here on Beesource would I find that you have participated in any other general bee discussion besides advancing your Neonic theories?
 
#19 ·
Quite a few beekeepers continue to advance the hypothesis that neonicotinoids are the sole cause for CCD. A quick scan through the threads on neonicotinoids here on Beesource will demonstrate just how frequently it is suggested.

Professional scientists have devoted large amounts of time and money to identifying a cause for CCD. With the emphasis on publishing in academia, and with the publicity that would accompany such a discovery, I think any number of scientists would have published such a simple result if evidence would have supported it.
 
#20 · (Edited)
Pretty interesting study on CCD and pathogens.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3424165/

Current evidence for a chemotoxic basis of CCD is equivocal. Honey bees have been exposed for many years to diverse anthropogenic chemicals, primarily agricultural applications aimed at reducing pest plants or arthropods. Chemical residues, including known insecticides, have been detected in bees and in hive materials (mostly wax and pollen) [11]. Recent evidence suggests the effects of low-level exposure to such chemicals range from impaired behavior (Henry et al., 2012) to lowered disease resistance (Alaux et al., 2012, Pettis et al., 2012), and further study of agrochemical toxicity is warranted. Nevertheless, neither individual chemicals nor overall chemical loads have been tied to increased risk of CCD; in fact, levels of the pesticides coumaphos and Esfenvalerate have been found at higher levels in control colonies as compared to CCD colonies
 
#21 ·
I would suggest that the OP search for a paper by May Berrenbaum(from teh U of Ill.) around 2007. She tested to see if CCD was of chemical origins, or pathogen origins. I forgot her methods, sorry. The conclusions where that it was a pathogen, which supported Hackenbergs conclusion.

A wise man above wrote:

I have the same problem as most people doing CCD research, finding the missing bees.

There is a report from a foreign country that analyzed those bee. The bees where placed in a "desert", 1/2 mile from a small cultivated nectar source. The author could not find any disease in the hives, but found plenty in the dead bees 1/2 mile away. Very simple, NOT very easy.

We saw CCD in 2005, 2006. Killed 90 percent for 2 years. Cleansed the hives and problems changed dramatically, and they made honey again. Don't forget the "don't make honey" CCD symptom. Do you have that?

So believe what you want.......

Crazy Roland
 
#23 ·
(Henry et al., 2012) to lowered disease resistance (Alaux et al., 2012, Pettis et al., 2012),
The Henry et al study noted that a neonicotinoid pesticide impaired foraging with bees less likely to return but it exposed the bees in the study to a level of pesticide considerably above levels typically found in pollen and nectar.
Alaux and Pettis both documented an interaction between a neonicotinoid pesticide and nosema in a lab study but Pettis noted that what he found in the lab was not replicated at the colony level for some reason.
I don't know if Alaux also saw this or whether he looked for it.

The most convincing study I have seen which suggests that neonicotinoids are a problem is the Whitehorn et al (Dave Goulson, Stirling University) which found that exposure of Imidacloprid reduced the size of bumblebee nests and reduced the number of queens produced on maturity of the colony.
Goulson looks at bumbles rather than honeybees.
 
#24 ·
I have followed the studies about CCD closely, and the evidence that neonics are the cause is overwhelming.
Many of those scientists that found otherwise have been exposed as having direct or indirect connections to the neonic manufacturers.

The question is no more if neonics cause CCD, it's how do they cause CCD.

As the bees' orientation has been shown to be compromised by neonics, isn't it plausible that their perception of day length could be compromised as well?
 
#27 ·
I have followed the studies about CCD closely, and the evidence that neonics are the cause is overwhelming.
Many of those scientists that found otherwise have been exposed as having direct or indirect connections to the neonic manufacturers.

The question is no more if neonics cause CCD, it's how do they cause CCD.

As the bees' orientation has been shown to be compromised by neonics, isn't it plausible that their perception of day length could be compromised as well?
Lots and lots of things are plausible, the real question is what is provable. You say there is no question that neonics are the problem yet you only offer casual anecdotal observations. Things like "he saw them leave and they didnt come back". Would be an observation easily made by a child. I asked some pretty basic questions in my previous post and you have chosen not to answer any of them. Lets start with these simple questions and see if we get an answer this time. Have your "healthy" bees had the same level of exposure to varroa as your friends dwindling bees? How do you and your friends monitor mite levels and what did you find? Are your beekeeping practices and equipment identical. Are your forage and climactic conditions at least similar if not identical and here is the "biggie" that anyone wants to know before considering if your theory makes any sense at all. Have either you or your friend ever had any sampling done of any bees or bee products for traces of neonics and if so what levels were found of what chemicals.
 
#30 ·
Many of those scientists that found otherwise have been exposed as having direct or indirect connections to the neonic manufacturers. -Stromnessbees
The scientists who work on these sorts of things are conscientious, hard-working sorts of folks. Simply the fear of being exposed by another scientist who wouldn't have the alleged sorts of connections would keep most anyone in academia from committing such fraud.
 
#34 · (Edited)
Interesting - they have CCD in varroa-free area?
There is little or no evidence of CCD anywhere in Europe.
There are people who try and attribute any colony death to CCD if the colony ended up with a small dead cluster.
This can happen with both varroa and nosema especially over winter when a colony dwindles.

It is a real shame to see the smears against Jerry Bromenshenk being repeated.

Some people quote the science if it suits, and then go in for personal attacks against the scientist when the findings don't fit the prejudice. This conspiratorial attitude is really unhelpful to the debate.

I don't actually think that Gerry Bromenshenk's theory about the iridovirus is likely to stand up over time but to label him a Bayer stooge simply because he is not blaming neonicotinoids is a disgrace.
 
#36 ·
Nice posts Jonathan and jclark. Stromnessbee clearly is more interested in chasing down pet theories and casting aspersions on a good bee researcher who has spent his career doing so much for our industry. I dare say Jerry wouldn't have based a study on two sets of hives when only was was exposed to varroa as Stromnessbee has offered up as evidence. Time might be better spent proving the existence of Nessie or Chemtrails.
 
#38 ·
.
I can see that several posters here really don't like the topic of the thread and desperately try to derail from it. :rolleyes:


Let's try to get back to the topic ...

There are not only unusual phenomena observed in honeybee colonies, they are noticed with bumblebees as well:

Some of them seem to be unable to recognize the seasons, just like the honeybee colonies:
Scientists investigate phenomenon of the 'winter bees'

It is one of the sounds of summer, but now the buzz of the bumblebee is becoming increasingly familiar in deepest winter – at a time when the insects should be hibernating.
...
The phenomenon has been recorded in the buff-tailed bumblebee (Bombus terrestris), one of the most common in the UK. Like other bees, it is usually only seen between March and September as it spends autumn and winter asleep underground, but there have been increasing reports of winter activity in recent years.
...
"Preliminary data collected by Marc Carlton shows that there is a second cycle active during the winter," Dr Ings added. "It doesn't seem to be the bees extending their life from the summer and lasting longer into the autumn. They are starting all over again in the winter."
...
Prof David Goulson, from the Bumblebee Conservation Trust and an academic from Stirling University, said: "The real puzzle is that it is not just a climate change thing. It doesn't happen in Brittany, for example, or anywhere else in the world.
...

http://www.telegraph.co.uk/earth/wi...nvestigate-phenomenon-of-the-winter-bees.html
 
#40 ·
.
I can see that several posters here really don't like the topic of the thread and desperately try to derail from it.
no most posters like topics when facts are posted. I have read many papers saying neonics can't bee shown as a problem, you don't show anything except what you think, now should I listen to the people doing the papers or you. I opt to listen to the people that know what they are talking about, like Dr. Jerry Bromenshenk.
 
#39 ·
Interesting news story, Stromnessbess, but the scientists in the story speculate about some factors and pesticide use wasn't among the factors in the story.

Certainly pesticide use has hurt bumblebees. Pesticide use hurts honeybees. But the connection between pesticides and CCD, I thought, is what you wish to persuade others in this thread.
 
#41 ·
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]
 
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