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ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #104103
Title: LATE-INSTAR EUROPEAN CORN BORER (LEPIDOPTERA:CRAMBIDAE) TUNNELING AND SURVIVAL IN VARIOUS TRANSGENIC CORN HYBRIDS

Author
item WALKER, KARLA - IOWA STATE UNIVERSITY
item Hellmich Ii, Richard
item Lewis, Leslie

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/5/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: Several types of genetically-engineered (transgenic) plants have been produced that kill insects when they feed. Scientists and crop producers are excited about these plants because they offer an effective way to kill pests without conventional chemical insecticides. Reduced chemical usage translates into less surface and ground water contamination. Dramatic control of pests on these plants, however, has many scientists concerned about pests becoming resistant to these plants. This study investigated whether European corn borer larvae are controlled when they eat specific tissues (pollen, husk, silks, and kernels) of four commercially-available types of transgenic corn. Survival on husks, silks, and kernels could compromise strategies to manage borer resistance to these plants. Results indicate that two of the four types of transgenic corn effectively controlled corn borer larvae when they were fed husks, silks, and kernels. This information will be useful for stakeholders (scientists, companies that produce these plants, producers, and consumers) interested in prolonging the value of transgenic plants.

Technical Abstract: Field studies were conducted in 1996 and 1997 to determine injury by and survival of late-instar European corn borer, Ostrinia nubilalis, on genetically altered Bacillus thuringiensis (Bt) corn. Cry1Ab events 176, Bt11, MON810, and MON802, Cry1Ac event DBT418, and Cry9C event CBH351 were evaluated. Plants of each corn hybrid were manually infested with either two 3rd, two 4th, or two 5th instar O. nubilalis. Larvae were held in clos proximity to the internode of the plant above the ear with a mesh sleeve. Larvae were put on the plants during corn developmental stages V8, V16, R1, R3, R4, R5 and R6. This study shows that not all Bt hybrids provide the same protection against O. nubilalis injury. Hybrids with Bt events Bt11, MON810, MON802, and CHB351 effectively protected the corn against tunneling by late-instar O. nubilalis. The 176 hybrid was effective in controlling late-instar O. nubilalis larvae during V8, V12, and V16 corn developmental stages, however, significant tunneling occurred by 4th-instars during R3 and R5. DBT418 was not effective in controlling late-instar O. nubilalis during corn vegetative or reproductive stages of development. Whether the Bt hybrids satisfied high- and ultrahigh-dose requirements is discussed.