SI
SI
discoversearch

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor.  We ask that you disable ad blocking while on Silicon Investor in the best interests of our community.  If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.
Non-Tech : Farming -- Ignore unavailable to you. Want to Upgrade?


To: Jon Koplik who wrote (101)11/30/2000 8:18:51 PM
From: Jon Koplik  Read Replies (1) | Respond to of 4443
 
Yet another story on monarch butterflies / Bt corn pollen, etc.

November 30, 2000

Scientists Count Weeds in Cornfields

By THE ASSOCIATED PRESS

Filed at 7:12 p.m. ET

WASHINGTON (AP) -- Scientists concerned that pollen from gene-altered
corn may be killing monarch butterflies wanted to know how much of the
insect's favorite food, milkweed, grows on farms. They found more of the
weed than they expected.

Half of Iowa's corn and soybean fields, and three-quarters of the roadside
and pasture land in the state contain milkweed, the Agriculture Department
said Thursday. Research by the University of Minnesota turned up similar
findings in that state.

The concern is that pollen from the gene-altered corn is landing on
milkweeds and killing monarchs.

``We didn't have a good idea whether there is a significant amount (of
milkweed) in corn fields or near corn fields,'' said Douglas Buhler, who
conducted the USDA research. ``It provides the information that people can
use to assess the potential impact'' of the genetically engineered corn.

The corn, known as Bt, contains a bacterium gene that makes the plant toxic
to moth larvae that are a major pest to farmers. An estimated 19 percent of
the 80 million acres of corn planted this year was Bt.

Laboratory research at Cornell University showed that the pollen was toxic to
monarchs, but it is still unclear whether the pollen is dense or toxic enough in
cornfields when the butterfly larvae are feeding to be a threat to them.

An Iowa State University study published this summer suggested it was. One
in five monarch larvae died after being exposed to the toxic corn pollen for
two days, the study found, but even that research was partially conducted
under lab conditions.

Farmers say the pesticides they use on conventionally bred corn are more of
a danger to butterflies and other insects than the Bt crops.

In Iowa, milkweeds cover about 0.03 percent of the state's corn and soybean
fields and 2 percent of other rural land, including roadside ditches and
pastures, according to the USDA study. Corn and soybean fields account for
78 percent of Iowa's land mass.

The Minnesota researchers, who have yet to publish their study, counted
butterfly larvae at five sites in the state this summer and found the caterpillars
were more common inside than outside cornfields. Weeds in cornfields
contained two to five times as many larvae or eggs as weeds elsewhere, said
Karen Oberhauser, who led the research.

It isn't clear why, although it could be because weeds grown in the fertile soil
of the fields are healthier or because the butterflies have fewer predators
when they are living among corn stalks, said Oberhauser.

``What this research says is that if pollen falls in densities that are high
enough to harm monarchs that the monarchs are there,'' she said.

Copyright 2000 The New York Times Company