Market Farming

[sgilman <sgilman AT netheaven.com>]

Subject: Re: Bees
From: "Bill Shoemaker" <wshoemak AT inil.com>
Date: Thu, 14 Jun 2001 15:44:18 -0500
X-Message-Number: 6

>Hello,
>     I'm not sure it is accurate to say crop spraying has nothing to do
>with the  susceptibility of bee populations to the mites. A more holistic
>point of view looks at the overall ecological impacts of pesticides,
>GMO's, and other agro-biocides that have been let loose in the
>environment. Bees, in their role of crop pollinators, may well be the
>Number One "non-targeted species" and after all, over 90% (!!) of applied
>pesticides miss their targets entirely.

There is no way you can justify that statement. By far, the greatest 
volume
and geographic application of pesticides is the application of herbicides.
Though drift is a serious problem, and one I fight continually in my area,
it would be grossly inaccurate to say that 90% of applied herbicides miss
their target entirely. The economics of that kind of efficiency would put
the practice on the shelf. Other pesticides (insecticides included) are 
also
targeted carefully by applicators for the same reason. Frankly, most feral
bees do not (or did not) live in an area where they were likely to come 
into
contact with a threatening pesticide.


>When you consider the research
>showing that bees pick up Sevin in pollen, for example, and bring it back
>to the hive where it can kill colonies outright, then it follows that the
>state of overall health for pollinators has been severely impacted,
>making them susceptible to the mites. Under this view, pests (the mites)
>are a symptom, not the cause.


Under that view, you are mistaken. Bees can pick up sevin in pollen and
carry it to the hive. This is particularly a problem when wettable powder
forms of sevin are used rather than liquids. But it does not happen often.
Most growers who spray sevin know that it will kill bees. They also know
that bees have a critical economic impact on the crop they are raising by
improving pollination, which leads to greater yield and quality of the 
crops
they are raising, whether it's cucumbers, pumpkins, melons, apples, pears,
peaches, blueberries, etc. Few use sevin during pollination because it
simply isn't necessary and because they realize the threat to the bees. 
Both
domesticated and feral bees need the protection and growers know it.

When I said estimates of bee losses from mites were up to 95%, my sources
were apiculturists who understand the pesticide problems for bees as well 
as
the impact of the varroa and tracheal mites. They contend that the losses 
of
feral bees are that high due to mites, not pesticides. Mites are the cause
of decline and death of the hives, not the symptom.

Bill Shoemaker
Sr Research Specialist, Food Crops
Univ of Illinois - St Charles Hort Research Center


Hello,
     I used Sevin as a well-researched example that illustrates both the 
extreme toxicity of the pesticide to bees and the fact that bees carry it 
back to the hive, with toxic effects on the entire colony. While I'm sure 
most growers would not willingly poison area bees by applying such toxins 
during pollination -- the timing of treatments is subject to a host of 
other economic, weather, pest pressure, time pressure, etc. constraints 
that can easily put pollinator safety lower down on the list. Further, I 
am not so sure homeowners have an equal awareness or understanding and 
sevin is a major garden pesticide.  Also, this ignores what else may be 
happening in the vicinity. Bees find many common weed plants very 
attractive, for example, leading to additional exposure to toxins applied 
to nearby crops.
     While sevin has been proven to be a smoking gun with direct links to 
killing bees, other pesticides may have somewhat lesser effects (ie they 
don't kill outright) but still have a major impact on bees and other 
pollinators.For example, French honey makers were up in arms a few years 
ago over the systemic pesticides which are sold to farmers as as seed 
coatings which are taken up by the seedlings and spread via the sap 
throughout the crop plants -- wheat, barley, corn and sugar beets -- to 
protect against greenflies. The bee keepers claimed the neurotoxicity of 
the systemic pesticide, present full time in the crop plant and also 
present in the nectars and pollen, had a disorienting and weakening 
effect on the bees, causing them to die because they couldn't return to 
their hives. They also claimed that bees only had to alight on the crop 
plant to become exposed. Further,traces of one pesticide that was studied 
(BayerAG's Gaucho) were found to persist at the site for another 2 years 
and were able to be taken up by subsequent crops. 

     The 90% figure (90% of applied pesticides miss their targeted 
species entirely) is from Pimentel. I had generally thought of it as 
having to do more with insecticides and fungicides that have well 
demonstrated toxic effects on beneficial insects and soil microbes. But 
since you raise the question of herbicides, since pre-emergence 
herbicides are applied to the SOIL at the time of planting and SOIL is 
alive with millions (per teaspoonful) of microbes, soil animals, flora 
and fauna as the basis for the entire soil foodweb (which includes bees 
-- and humans) then I'd have to say there's a HUGE impact upon 
non-targeted species here too. High power microscopy reveals there are 
very definite biocidal effects on soil organisms from the use of 
pesticides. Some are translocated to the soil via the root exudates 
plants put out to colonize symbiotic beneficial soil organisms for 
mineralizing nutrients, transporting water, etc. 
     A study I came across a while back says there is a global shortage 
of pollinators with declines in pollinator abundance, diversity and 
availability. Mites alone do not account for this phenomenon. It is 
highly reductionist to claim that pesticides have nothing to do with the 
the health status of bees (and their ability to resist mites). Pesticide 
use has increased some 50 fold since DDT was first used in 1945. During 
that same time, however, the toxicity of new pesticides has also 
increased 10 fold. This environmental factor has to be included in any 
assessment -- the agroecosystem has to be considered as a whole. Bees and 
other pollinators perform an incredibly important role in the foodweb and 
have now become an important canary in the coal mine for conventional 
agricultural practices and our food supply. Sure, mites are the immediate 
problem (symptom) but the question is why they have gained such 
ascendancy after years of relative peaceful co-evolution and coexistence 
with bees. It is simply not accurate to say pesticides have no effects in 
this process.... 

Steve Gilman
Ruckytucks Farm