monarch at saber.net
Tue Apr 16 18:02:10 EDT 2002
Mark Deering wrote:
> SO PAUL, YOU CAN SEE THAT THESE SCIENTISTS DO INDEED
> FEEL THAT ROUNDUP AND ATRAZINE ARE EFFECTIVE
> FOR MILKWEED.
Mark, I never said Roundup could not be effective on milkweed. At a
high enough dose it can even kill a tree. The main point of the Nebraska
weed scientists was that "common milkweed [Asclepias syriaca] is spreading
and infestations are becoming more severe" (side note: Lincoln Brower
has determined that Asclepias syriaca is the larval foodplant of 92%
of the monarchs that migrate to the overwintering sites in Mexico)
And the weed scientists attribute this increase to these factors:
1. "Less tillage is used in crop production today than in the past, creating
more favorable conditions for plant establishment and growth."
2. "Tillage implements cut and drag root sections of the plant,
which spreads it.
3. Cultivated land in eastern Nebraska is in row crops most of the
time, which provides a favorable environment for common milkweed.
4. Irrigation and fertilizer use are practices that enhance common
milkweed as well as crop growth."
5. "Herbicides are widely used today which often do not harm common
milkweed, but control most annual weeds that would otherwise
compete with it."
In my own milkweed garden , for example, I intentionally sprayed
Roundup a month ago in order to kill competing annual weeds.
Today, these annual weeds are dead, but healthy milkweed is emerging
from underground milkweed rhizomes.
In this way, a monarch gardener can use Roundup to create a
monoculture of milkweed for maximum monarch production.
The public, however, only hears very negative information about
herbicides and monarchs.
Like last month in a British newspaper Lincoln Brower told the
"I think the big lesson is that in the United States... the
real threat are the herbicides killing the milkweeds and
other plants the monarchs use for food"
Back in July 1988 Dr. Brower wrote an article in which he predicted the
likely end of the monarch migration by the year 2000. In
the article titled "A Place in The Sun" Dr. Brower stated: It's fabulous
migration...could well disappear by the end of this century"
But four months ago (Dec. 2001) the monarch overwintering
population in Mexico was measured at 110 million butterflies which is
about 40% ABOVE normal.
Despite this experience, Dr.Brower continues to predict the imminent
end of the monarch migration. Just two weeks ago he spoke at Colorado
State University and had this to say:
Subject: Re: Re: Comments on: Weather deals serios blow to monarchs
Date: Wed, 3 Apr 2002 22:01:57 -0700
From: "anita lahey" <anitalahey at hotmail.com>
To: "Paul Cherubini" <monarch at SABER.NET>
References: <200203202157.g2KLvPo26846 at listserv.umd.edu>
Well, Paul, I just heard Dr. Brower speak today here at
Colorado State University. We don't have long to wait to find
out which of the two of you is correct: he predicts complete
Monarch extinction within 10-20 years. He showed us a picture
of one of his assistants buried up to his neck in dead
Monarchs. They were three feet deep. Pretty convincing evidence
to me. He also showed a graph which correlated forest thinning to
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