Development of Diagnostic Concentrations for Monitoring Bacillus thuringiensis Resistance in European Corn Borer (Lepidoptera: Crambidae)

Authors

Paula C.R.G. Marcon, University of Nebraska-Lincoln
Blair D. Siegfried, University of Nebraska-LincolnFollow
Terrence A. Spencer, University of Nebraska-LincolnFollow
W. D. Hutchinson, University of Nebraska-LincolnFollow

Date of this Version

6-1-2000

Comments

Published in Journal of Economic Entomology Volume 93, Issue 3 (June 2000) pp. 925–930. Copyright 2000 Entomological Society of America. Used by permission.

Abstract

Two candidate diagnostic concentrations of the Cry1Ab and Cry1Ac toxins from Bacillus thuringiensis corresponding to the LC₉₉ and EC₉₉ (effective concentration that causes 99% growth inhibition) for European corn borer, Ostrinia nubilalis (Hubner), were determined based on previously obtained baseline data. Validation experiments using field-collected European corn borer populations from across North America showed that for Cry1Ab, a concentration corresponding to the upper limit of the 95% confidence interval of the LC₉₉, produced mortality .99% for all populations tested. However, for Cry1Ac, adjustments and further validation are probably necessary. Development of B. thuringiensis resistance monitoring programs that rely on diagnostic techniques are discussed.