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View Diary: Industrial agriculture is killing Monarch butterflies says Ellen Moyer (65 comments)

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  •  this seems to be a relatively minor effect, though (3+ / 0-)
    Recommended by:
    forgore, PeterHug, terabytes

    The USDA did a study to see how much Bt pollen was actually on the milkweeds, and how much was needed to kill the caterpillars:

    The studies in this project showed that monarch caterpillars have to be exposed to pollen levels greater than 1,000 grains/cm2 to show toxic effects.

    Caterpillars were found to be present on milkweed during the one to two weeks that pollen is shed by corn, but corn pollen levels on milkweed leaves were found to average only about 170 pollen grains/cm2 in corn fields.

    http://www.ars.usda.gov/...

    Of much greater significance seems to be the use of herbicides (including glyphosate) which simply kill the milkweed plants outright.

    No milkweeds=no butterflies.

    In the end, reality always wins.

    by Lenny Flank on Fri Apr 11, 2014 at 06:46:50 AM PDT

    [ Parent ]

    •  The article I reviewed on the Bt corn last month (0+ / 0-)

      supports your hypothesis, if I remember it correctly Lenny.

      My understanding is that the HT resistant crops allow farmers to apply higher amounts, and more toxic herbicides to their crops.

      When farmers spray the herbicides on their crops, wind blows it off the farmland to nearby natural areas killing the milkweed.

      And, as you say, no milkweed = no Monarch butterflies.

      Although, this "understanding" has been achieved so far only from reading a articles, many of them popular. My last formal courses in environmental science were some time ago.

      I have found no mention of transfer of herbicide from farms from butterflies, or other insects or animals moving about, or direct poisoning of butterflies, or caterpillars from pesticide blow-off, or during migration through farming areas.

      "Seriously, Folks, WTH?" - ("What the Heck? "h/t Joan McCarter, Seriously, Florida. WTF?)

      by HoundDog on Sat Apr 12, 2014 at 06:28:38 PM PDT

      [ Parent ]

      •  alas, some of our anti-science fringers here seem (0+ / 0-)

        eager to blame GMOs for everything up to the common cold, whether there is valid scientific evidence for it or not.  

        They do our side no good at all.

        :(

        In the end, reality always wins.

        by Lenny Flank on Sat Apr 12, 2014 at 07:47:11 PM PDT

        [ Parent ]

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