Bt Plant-Incorporated Protectants October 15, 2001 Biopesticides Registration Action Document
data with a higher percentage of Bt corn in the diet may be needed for a more thorough assessment of chronic risk, 3) if continuing non-target insect census data was available, long-range risk characterization might be improved, 4) additional Cry protein soil accumulation data is being considered to provide a more complete exposure characterization, 5) Bt cotton isolation distances may need revision in Hawaii, Puerto Rico, and the Virgin Islands due to gene flow concerns, and 6) informal consultation with the Fish and Wildlife Service wad initiated regarding the Karner Blue Butterfly.
a. Bt Corn
EPA has also reviewed the original data base and the new data, information, and comments regarding ecological effects for Bt corn. EPA has reviewed the potential for gene capture and expression of the Cry1Ab/Cry1F endotoxin in corn by wild or weedy relatives of corn in the United States, its possessions or territories. The Agency has determined that there is no significant risk of gene capture and expression of any B.t. endotoxin by wild or weedy relatives of corn product registrations in the U.S., its possessions or territories. In addition, the USDA/APHIS has made this same determination under its statutory authority under the Plant Pest Act.
The Agency has concluded that based on the weight of evidence there are no unreasonable adverse effects of Cry1Ab or Cry1F protein expressed in corn to non-target wildlife or beneficial invertebrates. However, EPA is requiring insect census estimates from representative fields to determine if there are long-term adverse impacts from the use of Bt corn, field tests of Cry1Ab and Cry1F protein accumulation and/or persistence in soil under a range of conditions typical of Bt crop cultivation as confirmatory data, and chronic avian data.
In the Cry1Ab ecological effects testing done, no treatment related effects were observed in Bobwhite quail or catfish fed Cry1Ab corn as part of their diet. No measurable deleterious effects from the Cry1Ab protein on honey bee larvae, honey bee adults, parasitic wasps, Ladybird beetles, green lacewings, Collembola (springtails), and Daphnia were observed in submitted studies.
In the Cry1F ecological effects testing done, no treatment related effects were observed in Bobwhite quail fed Cry1Ab corn as part of their diet. No measurable deleterious effects from the Cry1F protein on honey bees, parasitic wasps, Ladybird beetles, green lacewings, Collembola (springtails), earthworms, Daphnia, and Monarch butterflies were observed in submitted studies.
MON 810 and Bt11 show relatively low toxicity to monarch larvae and the Cry1F protein has no detectable impact on monarch larvae. Overall, the available information indicates a very low probability of risk to monarchs in areas beyond the near edge of corn fields. Inside corn fields and at the near edge of corn fields there is low probability of monarch larvae encountering a toxic level of pollen for the Bt corn products covered by this risk assessment.