Transgenic pollen harms Monarch Butterfly
Use the following website to research the effects of Transgenic pollen on
the Monarch Butterfly
http://cls.casa.colostate.edu/transgeniccrops/CTmonarch0.html
Success Criteria
 Describe the experiment
 Answer the ‘Questions to consider’

Make a decision as to whether it is true that "transgenic pollen harms monarch larvae"?
The following headline appeared in the scientific journal Nature on May 20, 1999:
Transgenic pollen harms monarch larvae
In a brief article, the authors described their results from experiments in which larvae (the caterpillar
life stage) of Monarch butterflies were fed milkweed leaves dusted with pollen from Bt corn plants.
Over the course of four days, 44% of the caterpillars that ate Bt corn pollen died. The scientists fed
another set of caterpillars milkweed leaves dusted with pollen from conventional corn, and fed a third
set of caterpillars no pollen, only milkweed leaves, which are the normal diet for Monarch caterpillars.
There were no deaths among the caterpillars that were fed conventional pollen or no pollen.
Caterpillar on a leaf dusted
with Bt pollen. Forty-four
percent of these caterpillars
died.
Caterpillar on a leaf dusted
with conventional pollen.
None of these caterpillars
died.
Caterpillar on a leaf, no pollen
added. None of these caterpillars
died.
Questions to consider:
Would you expect Bt corn pollen to kill Monarch
butterfly larvae?
Would you expect Bt corn pollen to kill other
insects in addition to Monarch butterfly larvae?
Would you expect other parts of a Bt corn plant
to kill insects?
Photo courtesy of www.MonarchWatch.org
Do you have enough information to make a decision about the truth of the statement that
"transgenic pollen harms monarch larvae"?
Yes, I have enough information to decide
No. Tell me more about:
Bt
Bt corn
corn pollen
Monarch butterflies
the experiment
the scientist
Is it true that "transgenic pollen
harms monarch larvae"?
Register your answer:
Yes
No