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United States Department of Agriculture

Agricultural Research Service

Research Project: PLANT RESISTANCE, BIOLOGY, AND RESISTANCE MANAGEMENT OF INSECT PESTS OF CORN

Location: Plant Genetics Research

Title: The Impact of MON863 Transgenic Roots is Equivalent on Western Corn Rootworm Larvae for a Wide Range of Maize Phenologies

Authors
item Hibbard, Bruce
item El Khishen, Ahmed - MAIZE RES SEC, ARC, EGYPT
item Vaughn, Ty - MONSANTO CORPORATION

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 18, 2009
Publication Date: August 1, 2009
Citation: Hibbard, B.E., El Khishen, A., Vaughn, T.T. 2009. The Impact of MON863 Transgenic Roots is Equivalent on Western Corn Rootworm Larvae for a Wide Range of Maize Phenologies. Journal of Economic Entomology. 102:1607-1613.

Interpretive Summary: Unexpected late-season damage has been seen with transgenic corn targeted toward corn rootworms. In order to help determine if the cause of this damage was reduced Bt protein levels late in the season, the effects of corn maturity on establishment, damage, and adult emergence of the western corn rootworm to transgenic corn and a non-transgenic corn line with the same genetic background was evaluated in field trials in 2002 and 2003. As expected, plant damage, western corn rootworm larval recovery, and adult emergence were significantly lower for transgenic than non-transgenic corn. The average weight of larvae and adults recovered from transgenic and non-transgenic corn were generally not significantly different. If western corn rootworm larvae were able to establish on transgenic rootworm-resistant plants, larval growth was relatively normal. Plant damage, the number of western corn rootworm larvae recovered, and adult emergence from transgenic corn did not significantly differ between egg hatch times at widely varying corn maturities in either year of the study. Although the extractable level of the transgenic protein decreased significantly for older corn in previous studies, in the current study, the amount of toxin did not vary in a way that affected neonate survival by western corn rootworm larvae in the field.

Technical Abstract: The effects of maize (Zea mays L.) phenology on establishment, damage, and adult emergence of the western corn rootworm (Diabrotica virgifera virgifera LeConte) to MON863 transgenic maize expressing the Cry3Bb1 protein and its isoline was evaluated in field trials in 2002 and 2003. As expected, plant damage, western corn rootworm larval recovery, and adult emergence were significantly lower for MON863 than isoline maize. The average weight of larvae and adults recovered from MON863 and isoline maize were generally not significantly different. If western corn rootworm larvae were able to establish on transgenic rootworm-resistant plants, larval growth was relatively normal. Plant damage, the number of western corn rootworm larvae recovered, and adult emergence from MON863 did not significantly differ between egg hatch times from widely varying phenologies in either year of the study. Although the extractable level of Cry3Bb1 decreased significantly from V4 to V9 maize in previous studies, in the current study, the amount of Cry3Bb1 did not vary from V3 to R3 in a way that affected neonate survival by western corn rootworm larvae in the field.

Last Modified: 7/24/2014
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