Here's very concerning study of pollen/neonics. Hope everyone reads it.
Detection of agricultural pesticides (and neonicotinoids in particular) in hives (including honey, pollen and wax) has been documented in the past: Bee-collected pollen was found to contain the neonicotinoid imidacloprid  in one study, although no adverse effects upon adults or brood were found . However, a more recent study found that rearing brood in comb contaminated with pesticides (including the neonicotinoids found in our study, thiamethoxam and clothianidin) led to delayed worker development . A field study examining the effects upon honey bees of clothianidin-treated canola found low levels of clothianidin in both pollen and nectar (0.93ppb and 2.59 ppb, respectively), but also found no significant effects upon honey bee populations . In studies in maize, guttation droplets produced by plants grown from neonicotinoid treated seed were shown to have from 10–100 mg/L of the pesticides and were found to cause paralysis and eventual death when fed to honey bees , while other studies have found traces of the seed treatment imidacloprid on vegetation near maize plantings and have hypothesized that sowing treated seed can cause dispersal of dust containing insecticide . Further evidence of detrimental effects of planting treated maize seed was noted by researchers in Italy, who found that honey bee mortality increased on the day seeds were planted and that numbers of foragers declined in the days following planting . A subsequent study demonstrated that bees that were induced to fly near a maize planter in Europe showed up to 100 ng of clothianidin/bee upon analysis. Interestingly, however, these bees did not die unless they were kept in conditions of high humidity .
Detection of clothianidin in pollen, both in stored pollen in cells and in pollen traps is a critical finding because clothianidin is even more toxic when administered to bees orally, with an LD50 of 2.8–3.7 ng/bee , . Given an average weight of 80–100 mg/bee, some of our pollen sample concentrations exceed the oral LD50. This, combined with the result that our samples of dead and dying honey bees consistently demonstrated the presence of clothianidin, suggests that the levels of both clothianidin and thiamethoxam found in our sampling of stored pollen in May of 2011 may have contributed to the deaths of the bees we analyzed. However, our analytical methods do not allow us to determine what fraction of the pesticide is on the surface of bees (contact toxicity, due to drift of soil or planter exhaust) vs. inside the body (oral toxicity, due to ingestion of contaminated pollen or guttation droplets). A combination of these exposure modalities is not unlikely.
Our results also demonstrate that clothianidin is present in the surface soil of agricultural fields long after treated seed has been planted in that field. All soil samples we collected contained clothianidin, even in cases where no treated seed had been planted for 2 growing seasons. During the spring planting period, dust that arises from this soil may land on flowers frequented by bees, or possibly on the insects themselves. Of potentially greater concern are the very high levels of neonicotinoids (and fungicides) found in the talc that has been exposed to treated seed, since part of this highly mobile material is exhausted to the outside environment during planting and after planting. The large areas being planted with neonicotinoid treated seeds, combined with the high persistence of these materials and the mobility of disturbed soil and talc dust, carry potential for effects over an area that may exceed the boundaries of the production fields themselves. A key mechanism for honey bee exposure may occur during the period when maize is typically planted across much of the Midwest (mid-April through early May). At this time, the energetic requirements of honey bee colonies are increasing rapidly and pollen and nectar resources are being gathered for colony growth. Talc and soil dusts from planting are mobile and have the potential to contaminate any flowering plants that are commonly found in or near agricultural fields and are visited by honey bees, including dandelion (Taraxacum officinale), which has been shown to be a preferred pollen and nectar source for honey bees during this period, when floral resources are relatively limited .
Later in the season, when planting is largely complete, we found that honey bees will collect maize pollen that contains translocated neonicotinoids and other pesticides from seed. Translocation of neonicotinoids into pollen has previously been reported for maize grown from imidacloprid-treated seed , although the degree to which honey bees in our study gathered maize pollen was surprising. The finding that bee-collected pollen contained neonicotinoids is of particular concern because of the risks to newly-emerged nurse bees, which must feed upon pollen reserves in the hive immediately following emergence. Pollen is the primary source of protein for honey bees, and is fed to larvae by nurse bees in the form of royal jelly. A bee will consume 65 mg of pollen during the 10 day period it spends as a nurse bee , therefore a concentration of 20 ng/g (ppb) in pollen would correspond to a dose of 1.3 ng (65 mg×20 ng/g) or almost 50% of the oral LD50 of ca. 2.8 ng/bee . Some of our pollen concentrations were even higher, although it is important to note that LD50 is measured as a one-time dose, while exposure through contaminated pollen would be spread out over the 10 d period and that there is likely substantial metabolic decay of the compounds during this time. Lethal levels of insecticides in pollen are an obvious concern, but sublethal levels are also worthy of study as even slight behavioral effects may impact how affected bees carry out important tasks such as brood rearing, orientation and communication.
Also potentially important are the three fungicides found in bee-collected pollen samples (trifloxystrobin and azoxystrobin and propiconazole). Azoxystrobin and trifloxystrobin are frequently used in maize seed treatments as protectants and all three of these compounds are also widely applied to maize in North America, even in the absence of disease symptoms . These compounds are typically applied using aerial application during anthesis. Propiconazole has been shown to synergize toxicity of some neonicotinoids (thiacloprid and acetamiprid) to honey bees in the laboratory, although the same results have not been shown in field studies , . Although these fungicides are not acutely toxic to honey bees , the fact that they are routinely applied to areas that bees will frequent (i.e. maize plants at anthesis) coupled with the difficulties and uncertainties in assessing the toxicity of pesticide mixtures , indicate that they should be considered in future work.
In evaluating our results, it is important to bear in mind that toxicity is only one variable in addressing pesticide risks to pollinators – the intersection between toxicity and exposure is key in determining how much risk is posed by a toxicant to a given organism. These components are assessed by regulators in developing a “risk cup” which combines these parameters to assess the cumulative risks of a given toxicant to an organism . In the case of honey bees, the toxicity of the neonicotinoid seed treatments used for large acreage field crops has been well-established , , although when assessing the overall threat to posed to honey bee populations, calculations are complicated even further by the observation that sublethal doses of insecticides can weaken bees and increase susceptibility to key parasites or pathogens .
Because we found these compounds in pollen, oral LD50 is a relevant parameter in discussing toxicity to honey bees. In terms of acute toxicity (based on the oral LD50 of 2.8 ng/bee ), the amount of clothianidin on a single maize seed at the rate of 0.5 mg/kernel contains enough active ingredient to kill over 80,000 honey bees. However, the overall level of risk has been more difficult to quantify, as there has not been a clear mechanism whereby honey bees could be exposed to high levels of these compounds – once the treated seed is planted, opportunities for honey bee exposure to concentrations of neonicotinoids over a wide area should drop dramatically (although see ). Our results suggest that of the factors we quantified in this study, used talc exhausted during and after planting (the latter would occur during routine cleaning of planting equipment) stands out as potential routes for exposure that should be prioritized for further quantification and remediation. A recently published review of the risks posed by planting treated seeds in the E.U. estimates that measures taken there may reduce the dust generated during planting by 99% . In North America, different planting equipment is used and there are currently no guidelines for disposal of waste talc, nor are there devices for filtering exhaust material from the vacuum planting systems. Producers may be largely unaware that this material is highly toxic to pollinators. However, given the unprecedented levels of maize production across the United States, coupled with the increasing adoption of neonicotinoid seed treatments in other annual crops covering a wide area, including soybeans (31.3 million ha), wheat (24.7 million ha), and cotton (4.4 million ha, all figures 2010 planting) , it is clear that this material presents a risk that is worthy of further investigation and possibly corrective action.
Our findings have implications both for honey bees located near these crops year-round, but also for migratory colonies (bees used to pollinate winter-flowering specialty crops in western North America, such as almonds and other fruit and nut crops). Many of these colonies reside in areas where treated seed is used extensively (i.e. the upper Midwestern United States) during the period from early spring through late fall. During this period, these bees forage on a variety of crops that may be planted using neonicotinoid treated seed, including maize, soybeans and canola. Although our study was confined to honey bees, these results are relevant for any pollinators that forage in or near agricultural fields, both in the crop itself or on other flowering plants (i.e. weeds) that are present in or near the field.
cam, here's what randy oliver had to say about the krupke study:
"Planting dust: Krupke (2012) contained little new information–planting dust can cause bee mortality; the test colonies recovered (Greg Hunt, pers comm). Points out potential synergies with fungicides—there are also other pesticides in the dust. There is a large body of research already published on this issue—see Krupke’s or Marzaro’s (2011) references sections."
interesting that those colonies recovered. hopefully the dust issue is being addressed by the agricultural community.
Well I've read Randy for a while. I have 100% confidence in the mans integrity.
I think these vague character assassinations suck.
Am I going to have to limit you in your posting in the top thread? I don't want it filled with stuff like this:
Neonicotinoids – is it time for them to buzz off?
by Veronica Peerless, Gardening Deputy Editor
Energy & Home
14 February 2013
It’s been a tough few years for bees, with numbers dropping in the UK and internationally. Could agricultural insecticides be to blame? Do you use insecticides to keep your garden pest-free?
The comments below this article are particularly interesting!
We could fill 100 pages with stuff like this. I want to limit info in the top thread to real studies and articles written by people who are in the field actually doing the work, not some garden editor. So either limit it yourself or I'll do it.
And I suppose you receive advice from God. You're tune is getting old. Randy Oliver is the best source of information that normal beekeepers have. He makes most of his living off bees and also shares his extensive knowledge of science with us. You've finally made my ignore list.
So if Bayer where to actually do genuine studies. Just who should they go to? It is not really much of an argument to say that anyone that would research for Bayer is then somehow discounted.
So you call Randy Oliver into question. And you don't even have the courage to do it clearly and distinctly. I challenge on that and now invite you to support that claim in detail tell us exactly what Randy has ever said that indicates his work is wrong suspect or unreliable. I say it is obvious that all apply liberally to your claim.
>I hope that you are aware that Randy Oliver has received funding from Bayer
oh, was that was in one of those ignored posts? how funny.
i am proud to say that randy has received funding from me too, and many other interested and concerned beekeepers as well.
That may be, but anyone who relies totally on reviewed and parsed information in preference to primary sources is in for a rude shock. There is a reason published authors are discouraged from relying on secondary (review work just like Randy's) sources. Namely that you have no idea of the veracity and just what "filtering" the author put the primary materials through to arrive at their interpretation.Quote:
Randy Oliver is the best source of information that normal beekeepers have.
Long story short do the reading, if you don't understand something ask, there are LOTS of very knowledgeable people here. It really is that simple, relying on another's interpretation of another's work (add as many steps to this chain as you like) is not a good idea.
Let me give you an example of how Randy Oliver works, right from the front page of his website:
I hope you have already read the 'Harvard Study' which he discusses there, if not you will find it here:
Randy does give you the link on his page, but only half way down the page, after he has already thrown a lot of dirt at it, so most beekeepers wont' bother to read it for themselves.
Now this study has got a very interesting outcome:
It replicates the main symptoms of CCD!
As a scientist, whenever you can replicate a complex set of symptoms with an artificial setup, you know that you are onto something.
Nobody else had achieved this for CCD at the time.
OK, the study setup was not perfect, there are a few details that could be improved in a follow up study, but the cat is out of the bag, we have got a good start to studying CCD, and it's highly likely that the neonics have got a lot to do with it.
But Randy Oliver ignores this achievement and concentrates only on rubbishing the study and its author.
He never calls for a follow-up study with an improved setup, and that's what makes me wonder about his integrity.
In his 'analysis' he completely ignores the fact, that 15 out of the 16 treated colonies died with symptoms similar to CCD
Instead, he concentrates a great deal on the dosing regime and just declares: 'it is amazing to me that the colonies were not killed outright!'
Well, it is amazing, I agree, but the conclusions we should draw from this statement are very different from the ones he draws:
Isn't this exactly what we see happening all over the place: bees not directly affected by foraging on neonic treated crops, but their colonies collapsing months after the exposure?
The increase in the dosing regime can actually be explained very easily:
Chensheng Lu obviously wanted to avoid killing his bees outright, and as it is difficult to know how much other forage they might take in, thereby diluting the dosing from the feeders, he started the treated colonies on very small amounts of Imidacloprid.
After noticing no effects, he increased the dosing rates to the next level, and was still able to avoid direct damage to the colonies.
If you look carefully, you see that he works with 8 different concentrations, ranging from 0.1 to 400 μg/kg in the weekly feed (2.6 kg of HFCS).
By reading the study for what it is, and suggesting certain improvements to help further clarify the issue, Randy Oliver could have done beekeepers all over the world a great favor.
But by rubbishing it throughout, he more or less created a precedent, discouraging other researchers from even looking at the issue, and leaving beekeepers confused and misinformed.
Randy Oliver has clarified the Bayer thing many times and has often said he will be the first on their case if he finds evidence to condemn any of their products.
If you read what he writes he has highlighted several areas of concern with regard to Bayer products - dust clouds at seed drilling is the most obvious one which springs to mind.
Jerry Bromenshenk got the same smears when he suggested bee problems which were not directly related to neonicotinoid pesticides.
In fact, anyone who suggests that bee problems are not a single issue directly related to neonicotinoid pesticides gets this smear treatment to a greater or lesser extent, even the humble posters on sites such as this.
One guy on the UK beekeeping forum claimed recently that all the garden forums have been 'infiltrated' with 'Industry' shills.
Randy Oliver and Jerry B mostly post on Bee-L where this stuff has come up several times.
Randy on several occasions has volunteered donated many hundreds of his own colonies to various experimental studies at his own cost. He often loses the lot. This is for the general good of beekeeping and I for one am glad there are altruistic individuals like Randy Oliver willing to help.
Happy to, I get 100% from the Australian government as student support. Yep no industry funding one way or another, AT ALL.