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Fwd: SF Chronicle article herbicides and butterflies
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Richard Worth
Apr 4, 2012, 4:31:02 PM4/4/12
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FYI. link below.
Begin forwarded message:
Please see this article about herbicides used to kill invasive weeds and impacts to native butterflies.
Weed killers threaten Lange's metalmark butterfly
San Francisco Chronicle
Weed killers commonly used to control invasive plants in the Bay Area also kill off butterflies, a federal toxicology study has found. Butterfly populations common to the Antioch Dunes National Wildlife Refuge dropped by as much as a third when the larvae and host plants were sprayed with each of three standard herbicides, according to the study commissioned by the U.S. Fish and Wildlife Service…
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2012/04/01/BAUU1NR4OH.DTL
Richard Worth
Entomologist / Lepidopterist
Plant Division
Oregon Dept. of Agriculture
635 Capitol St. NE
Salem, OR 97301
503-871-7108: cell
So many moths, so little time...
Paul Cherubini
Apr 4, 2012, 5:32:12 PM4/4/12
to
> http://tinyurl.com/cebyhx3
> "Key to the butterfly’s survival is the naked stem buckwheat
> plant, which is easily overgrown by the non-native plants
> ripgut brome, vetch and yellow starthistle.
> Refuge managers have tried to weed by hand but the process
> risks disturbing the buckwheat plants and butterfly eggs and larvae.
> And when refuge managers started spraying the plants with herbicides,
> they noticed the butterfly populations were dropping even more,
> says Stark.
> Each of the three herbicides in the Stark study operates differently,
> leading the researchers to think butterflies are being affected by
> inert ingredients or an effect on the butterflies’ food source.
Sounds like the naked stem buckwheat plants had caterpillars
that were being sprayed directly (along with the invasive plants).
So why should anyone be surprized there was some caterpillar
mortality? Herbicide sprays routinely contain surfactants, just
like kitchen dishwashing liquids do, that sometimes kill insects
that get a soaking wet dose.
So the actual herbicides (minus surfactant and emulsifier)
may have been harmless.
These media articles (including University news articles) are
unbalanced because the reporters don't contact the chemical
companies to give them a chance to voice their side of the story.
Paul Cherubini
------------------------------------------------------------
For subscription and related information about LEPS-L visit:
http://www.peabody.yale.edu/other/lepsl
> "Key to the butterfly’s survival is the naked stem buckwheat
> plant, which is easily overgrown by the non-native plants
> ripgut brome, vetch and yellow starthistle.
> Refuge managers have tried to weed by hand but the process
> risks disturbing the buckwheat plants and butterfly eggs and larvae.
> And when refuge managers started spraying the plants with herbicides,
> they noticed the butterfly populations were dropping even more,
> says Stark.
> Each of the three herbicides in the Stark study operates differently,
> leading the researchers to think butterflies are being affected by
> inert ingredients or an effect on the butterflies’ food source.
Sounds like the naked stem buckwheat plants had caterpillars
that were being sprayed directly (along with the invasive plants).
So why should anyone be surprized there was some caterpillar
mortality? Herbicide sprays routinely contain surfactants, just
like kitchen dishwashing liquids do, that sometimes kill insects
that get a soaking wet dose.
So the actual herbicides (minus surfactant and emulsifier)
may have been harmless.
These media articles (including University news articles) are
unbalanced because the reporters don't contact the chemical
companies to give them a chance to voice their side of the story.
Paul Cherubini
------------------------------------------------------------
For subscription and related information about LEPS-L visit:
http://www.peabody.yale.edu/other/lepsl
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