Jonathan Lundgren gave two talks at the ESHPA meeting. The first was titled "How the EPA Does Risk Assessments of Pesticides".  I started a thread on that talk under the subject heading "Lundgren on RNAi at ESHPA fall meeting".


The second topic was much more global.


Lundgren began by noting that honeybees today are challenged by multiple stressors, listing all the usual examples from Varroa, viruses, and nutrition, to chemical ones such as the 'cides.


He said that most approach each stressor as a separate problem to solve, but in fact all of the problems would become resolved (meaning we'd have healthy bees and good crops) if we understood that the root of all the trouble is not a "bee problem" but a biodiversity problem.  In other words, the multiple problems stressing bees would be minimized and bee health and productivity would improve by changes to the way we manage biodiversity.


He then said that agroecosystems have become the largest biome ON EARTH (!!!) (One assumes he is not including marine ecosystems!)


He said that agroecosystem management as practiced by the majority in the USA today causes these problems:


1.  Reduced biodiversity, not just because herbicides, fungicides, and pesticides reduce a large number of species in the fields, but also because we are cultivating fewer crops and those are becoming genetically less and less diverse through rigorous genetic manipulations and standardization of seeds.

2.  Simplified cropping systems, exemplified by crops such as corn.  Corn is now 30% of the crop area in the USA, and covers 5% of the total land area.  The market pressure on corn (exacerbated by ETOH and fuel laws) results in corn-on-corn planting (no rotation) and this can only be done with Bt corn....meaning most of the corn planted now is GMO corn.

3.  These negative changes are driven by three things; evolving technologies, social values, and market forces, that dictate farmer and consumer behavior.


When he and his lab team did a study of pesticide distribution within crops and within the surrounding field margins/hedgerows/ditches, they could not find any areas that did not contain neonics and other pesticides.  They could only find some areas with less concentrated pesticides.  This is because many of the compounds persist in the environment and are water-soluble.  He said that 10% of our total land area has predominantly GMO crops and persistent neonicotinoid residues.


So the next part of the study asked the question:  What is the biodiversity within the agroecosystem?  They took bioinventories....complete records of invertebrates in the soil and on the plants.


He said we have limited understanding of what he calls "bio-networks".  This lack is pointed out in papers such as:


Crowder, David W., et al. "Organic agriculture promotes evenness and natural pest control." Nature 466.7302 (2010): 109-112.


Results:  They found 107 insect species in the canopy of the crops.  7% of these (about 8) were pests, but did not occur at economically damaging levels.  13% of the species were minor pests.  The majority of the remainder were natural enemies of the pest insects.


Lundgren stated that rich biodiversity reduces the pest pressure on corn.  His work was published:


Lundgren, Jonathan G., and Scott W. Fausti. "Trading biodiversity for pest problems." Science Advances 1.6 (2015): e1500558.


Think of biodiversity as a giant network, like a spiderweb.  As links are removed, pests increase....meaning that biodiversity influences the magnitude of the pest populations.  Biodiversity provides services and performs functions that can not be indefinitely replaced by technology.


What to do?


1.  Reduce disturbance to increase diversity.  Tillage, for instance, reduces soil diversity.

    Heal the soil and help solve bee problems.

2.  Crop rotations, smaller plots, more crops, cover crops, conservation strips, field margins, weeds, intercropping all help increase diversity and are proven to still be profitable.


Andow, David A. "Vegetational diversity and arthropod population response." Annual review of entomology 36.1 (1991): 561-586.

Letourneau, Deborah K., et al. "Simple-but-sound methods for estimating the value of changes in biodiversity for biological pest control in agriculture." Ecological Economics 120 (2015): 215-225.


He then listed a number of farmers who have started to adopt this approach in the USA.  Ironically, by returning potato fields to a fallow year (instead of a barley crop), profits actually went UP.  During the fallow year, the farmers plant green manure and graze that.  Production costs go down, profits are steady or better than when the two monocultures are rotated.  He named specific large-scale farmers and the states they live in, a list I copied and can share here if anyone wants that information.


One of these farmers, David Brandt, of Carroll, OH, plants 10 acres with neonics and the rest of his acreage without them.  He gets a lower yield on the treated acres.  Lundgren asked him....why do you continue to plant neonic-treated crops on those 10 acres?  The answer:  His crop consultant said neonic treatment increases yield, so he plants that 10 acres year after year just to prove the consultant is full of s***.


Lesson:  We can coexist with all the species that share the crop space.  Up to 40% of our land space is agriculture.  Changing our farm practice will have to happen to improve the situation for our bees.


You can reach Dr. Lundgren at:  [log in to unmask]


Christina


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