[Pollinator] Fwd: [New post] Honeybees and Corn 2016

Mon Sep 12 11:09:13 PDT 2016

Actually that was Dively et al. (2015), my mistake for mis-citing.

On Mon, Sep 12, 2016 at 11:07 AM, Stephanie Parreira <
parreirastephanie at gmail.com> wrote:

> Hi Peter,
>
> Actually, in a corn agroecological system, pollen from the treated corn
> would probably pose the lowest risk for honey bees. The bees at greatest
> risk would be those exposed to the blowing neonic-laden dust and nearby
> water sources. Very low levels of neonicotinoids end up in corn pollen
> because it is seed-treated. If it were a different system, i.e. fruit
> orchards, contaminated pollen and nectar would be a much greater problem,
> because orchard trees are treated with soil and trunk injections rather
> than seed treatments. Soil and trunk treatment results in much higher
> concentrations (and we might assume persistent concentrations, based off
> the data from ash trees, but there are no data on persistence in orchard
> trees)  in the crop plant tissues, pollen, and nectar.
>
> You are correct that honey bees visit corn to collect pollen, mostly
> because it is the most abundant source in the area and not because it
> provides any ample nutrition. If there were sufficient amounts of
> alternative forage nearby that provides both nectar and pollen, in high
> quantities, there may be less foraging on corn (I say may because at this
> time it does not look like bees select pollen based off nutritional
> quality--they only do this with nectar).
>
> With that said, a study based on one site and one season is pretty much
> guaranteed to fail to detect any real patterns in colony health and
> mortality.
>
> John, I would take the weight gain results with a grain of salt for
> another reason. Weight is not the best measure of colony health because
> there is no way to separate weight from honey from weight of bees, brood,
> or pollen. You can have a failing colony from any given cause (mites,
> viruses, or pesticides) with few bees because many of the bees died, but
> these colonies may still lot of honey that makes up most of the weight in
> the colony because there are fewer bees to eat it. A healthier and more
> populated colony might weigh a little less because there are more bees
> eating honey (also keep in mind that the bees:honey ratio is going may mean
> very different things at different times of the year).
>
> I would also advise against using residues of neonics in the bees
> themselves to determine whether they have been poisoned. Neonics like
> imidacloprid are metabolized very quickly and will not be present in the
> bees after a few hours, unless they consumed a ridiculously high (not
> field-realistic) amount. It is far more useful to take samples of pollen
> and nectar of forage flowers, stored pollen, and nectar to really
> understand colony pesticide exposure. Not enough studies have done this,
> and the studied that do don't do the best job at getting a representative
> sample from the colony. If you do sample honey and pollen from inside the
> colony, several samples should be taken from several frames and then
> combined for analysis, rather than removing a little square from one frame
> and assuming that it represents all pollen in the colony. (Personally, I
> think we really need a study that determines how pesticide residues differ
> in different parts of the colony--this would be extremely useful to
> sampling in other studies).
>
> Another note about the vanEngelsdorp et al. (2015) study (I think this is
> the one you are referring to but I may be wrong--if you aren't discussing
> the neonic feeding experiment then disregard this comment) is that colonies
> exposed to neonicotinoids had higher levels of *Varroa* mites, and
> colonies at the higher concentrations of 20 ppb and 100 ppb had higher
> mortality than those in the control group and 5 ppb treatment group. I did
> not like that the authors concluded that those results were irrelevant
> because the concentrations were high--the maximum concentration detected
> bee bread in Mullin et al. (2010) was 206 ppb, which is over double the
> highest concentration used in the experiment.
>
> Wow, I got a little long-winded there. Sorry folks.
>
> Stephanie
>
>
>
>
> On Mon, Sep 12, 2016 at 10:10 AM, Peter Bernhardt <bernhap2 at slu.edu>
> wrote:
>
>> Very good.  Let's consider a little detective work.  "Neonics" are most
>> likely to harm those honeybees collecting pollen produced by systemically
>> treated corn seeds, right?  Why would honeybees visit male flowers of a
>> wind-pollinated plant in which grains are packed with starch instead of
>> amino acids and lipids?  The usual answer, based on a long history of
>> literature, is that honeybees only visit corn tassels when there's little
>> else on which to forage.  Townsend's bees had a "good year" in which forage
>> plants were plenty and the workers did not have to seek out what
>> anthropologists call "famine foods" when studying human populations. That's
>> why can't always predict success of failure in a multi-factorial system in
>> agriculture (like bee-keeping) restricted to one site and season.
>>
>> Peter
>>
>> On Sat, Sep 10, 2016 at 1:28 AM, Kit Prendergast <
>> kitprendergast21 at gmail.com> wrote:
>>
>>> I fully support Stephanie's conclusion and could hardly have put it
>>> better myself. One needs to actually measure bee keeper practices ( and one
>>> has to ask how reliable are self-reports? How consistent are the behaviour
>>> of beekeepers across seasons?), pesticide exposure, pathogen exposure,
>>> climatic variables, foraging resources available in the environment (pollen
>>> and nectar resource abundance, and their distribution across the
>>> landscape), perhaps even competition between different bee populations
>>> (managed, wild, and native), or predators, to parse out the effects of
>>> various factors that might contribute to honeybee health. What has been
>>> recently shown in both lab and field studies is that pesticides do
>>> negatively affect honeybee survival and foraging ability at concentrations
>>> experienced in nature. It is also consistently shown that loss of flowering
>>> plants has a negative effect on pollinators, including on pollinator
>>> health. Pesticides also can stress bees, interacting with other stressors
>>> like nutritional limitations, adverse weather, and pathogens.
>>> Given that pesticides are known to affect other pollinators and insects,
>>> it is parsimonious to conclude that honeybees are also affected, whereas
>>> anecdotal reports of bad beekeeper management based on single examples that
>>> do not stand up to scientific rigour (replication, controls etc.) cannot be
>>> considered to be reliable.
>>> Regards
>>>
>>> On 10 September 2016 at 05:42, Stephanie Parreira <
>>> parreirastephanie at gmail.com> wrote:
>>>
>>>> This is a highly over-simplified opinion about the neonicotinoid
>>>> problem. I would have further questions for the above person, such as, are
>>>> there weather differences between the region where the colonies died and
>>>> the place your colonies are (windy conditions can blow neonic-laden dust
>>>> into colonies and onto foraging bees, so if one place is windier than the
>>>> other, bee exposure and response may be different)? Is the area of planted
>>>> corn significantly different from the area of corn in Ontario (more corn
>>>> planted = more potential exposure to neonics and less alternative forage)?
>>>>
>>>> Anecdotal evidence will do no one any good, whether that anecdotal
>>>> evidence argues against neonicotinoid use or for it. We should take things
>>>> like this with a grain of salt and understand that there are many factors
>>>> at play that may increase the potential of pesticides to severely affect
>>>> honey bee colonies.  I am not saying that beekeeper practices cannot be
>>>> improved to increase colony survival, but to blame beekeeping practices
>>>> without any comparison or contrast between beekeeping practices, landscape
>>>> and foraging environment, and pesticide exposure (in-hive or forager
>>>> residues), it is irresponsible to jump to this conclusion.
>>>>
>>>> (Furthermore, even if neonicotinoids are not the issue for honey bee
>>>> colonies specifically, we should still be concerned about their many
>>>> detrimental effects on native bee populations, which have been demonstrated
>>>> in the scientific literature time and time again.)
>>>>
>>>> On Thu, Sep 8, 2016 at 7:24 AM, Laurie Adams <lda at pollinator.org>
>>>> wrote:
>>>>
>>>>>
>>>>>
>>>>> ---------- Forwarded message ----------
>>>>> From: John Purdy <johnrpurdy at gmail.com>
>>>>> Date: Thu, Sep 8, 2016 at 6:59 AM
>>>>> Subject: Fwd: [New post] Honeybees and Corn 2016
>>>>> To: Laurie Adams <LDA at pollinator.org>
>>>>>
>>>>>
>>>>> Here is an important observation from a beekeeper in western Canada.
>>>>> It helps to build confidence in what I found in my recent bee health study.
>>>>> perhaps it is worth posting. (a section is a mile square or 640 acres)
>>>>>
>>>>> John
>>>>> ---------- Forwarded message ----------
>>>>> From: Alberta Buzzing <donotreply at wordpress.com>
>>>>> Date: Sun, Sep 4, 2016 at 10:40 PM
>>>>> Subject: [New post] Honeybees and Corn 2016
>>>>> To: johnrpurdy at gmail.com
>>>>>
>>>>>
>>>>> Lee Townsend posted: "I had a yard of 40 hives on a quarter section of
>>>>> treated corn this year, and it is interesting as I am not seeing any of the
>>>>> effects on the bees that groups like the Ontario Beekeepers Association
>>>>> claims to take place in this situation.  My bees are of th"
>>>>>
>>>>> New post on *Alberta Buzzing*
>>>>> <http://albertabuzzing.com/?author=1> Honeybees and Corn 2016
>>>>> <http://albertabuzzing.com/2016/09/honeybees-and-corn-2016/> by Lee
>>>>> Townsend <http://albertabuzzing.com/?author=1>
>>>>>
>>>>> I had a yard of 40 hives on a quarter section of treated corn this
>>>>> year, and it is interesting as I am not seeing any of the effects on the
>>>>> bees that groups like the Ontario Beekeepers Association claims to take
>>>>> place in this situation.  My bees are of the same species that are in
>>>>> Ontario, the corn is treated the same way as it is in Ontario, and the
>>>>> planting was done the same as in Ontario.
>>>>>
>>>>> Leads me to think the problem is not neonics, but beekeeper
>>>>> management.  It is truly unfortunate that the Ontario Beekeepers
>>>>> Association and groups like it refuse to admit what exactly they are doing
>>>>> with their colonies, with proof to back up their claims.
>>>>>
>>>>>
>>>>> *Lee Townsend <http://albertabuzzing.com/?author=1>* | September 4,
>>>>> 2016 at 8:40 pm | URL: http://wp.me/p5JjBC-1X
>>>>>
>>>>> Comment
>>>>> <http://albertabuzzing.com/2016/09/honeybees-and-corn-2016/#respond>
>>>>>    See all comments
>>>>> <http://albertabuzzing.com/2016/09/honeybees-and-corn-2016/#comments>
>>>>>
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>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> John Purdy PhD
>>>>> Environmental Scientist
>>>>> Abacus Consulting Services Ltd
>>>>>
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>>>>>
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