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Article
Larval distribution and survival of second generation European corn borer, Ostrinia nubilalis (H.ubner) (Lepidoptera: Crambidae) on Event 176 Bt Corn
Crop Protection
  • Amelia C. Zoerb, University of Nebraska-Lincoln
  • Terence Spencer, University of Nebraska-Lincoln
  • Richard L. Hellmich, Iowa State University
  • Robert J. Wright, University of Nebraska-Lincoln
  • Blair D. Siegfried, University of Nebraska-Lincoln
Document Type
Article
Publication Date
1-1-2003
DOI
10.1016/S0261-2194(02)00143-6
Abstract

European corn borer Ostrinia nubilalis H.ubner (Lepidoptera: Crambidae) larvae that have completed development on Event 176 Bt corn hybids have either survived exposure to sublethal doses of Cry1Ab Bt toxin or exploited plant tissues that do not express the toxin. To evaluate the impact of such exposure on larval establishment and survival, Event 176 plants with and without tassels and a non-Bt isoline were infested with O. nubilalis egg masses during anthesis. On the non-Bt plants, larval establishment occurred primarily on pollen collecting in the leaf axils, silks and ears. In contrast, almost no larvae were recovered from leaf axils of the Bt treatments and at least 50% fewer larvae were recovered from the silks and ears during the first 2 weeks after infestation relative to the non-Bt plants. The larvae recovered from Bt treatments weighed significantly less than those observed in the non-Bt isoline at 4 weeks after infestation. By the eighth week, the larval weights of all three treatments were similar in three of four different field tests, suggesting that second generation larvae have the ability to compensate for initial exposure to sublethal doses of Bt toxin. In laboratory assays involving exposure of neonate larvae to silks of Event 176 and non-Bt corn, survival of neonate O. nubilalis was not different although larval weights were significantly reduced (2- to 6-fold). These results suggest that second generation larvae completing development on Event 176 corn do not completely avoid exposure to the Bt toxin, although those that do survive are able to compensate for these sublethal effects. The implication of these results is that Event 176 hybrids do not appear to satisfy requirements for high dose that are recommended for resistance management purposes.

Comments

This article is from Crop Protection; 22 (2003); 179-184; doi: 10.1016/S0261-2194(02)00143-6

Rights
Works produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted.
Language
en
Date Available
2014-08-26
File Format
application/pdf
Citation Information
Amelia C. Zoerb, Terence Spencer, Richard L. Hellmich, Robert J. Wright, et al.. "Larval distribution and survival of second generation European corn borer, Ostrinia nubilalis (H.ubner) (Lepidoptera: Crambidae) on Event 176 Bt Corn" Crop Protection Vol. 22 (2003) p. 179 - 184
Available at: http://works.bepress.com/richard_hellmich/68/