J.C. PERSHING
Monsanto Co., 700 Chesterfield Pkwy North, Chesterfield, MO  63198

Maize is the largest crop in the United States in terms of acreage planted and net crop value.  In 2000, the U.S. maize crop covered 79 million acres.  The western corn rootworm (CRW), Diabrotica virgifera virgifera LeConte, (Coleoptera: Chrysomelidae) is one of the most serious pests of maize in the United States.  Larvae damage maize through feeding on the roots, which reduces the ability of the plant to take up water and nutrients from the soil and causes harvesting difficulties due to lodging.  There are currently two common options for controlling CRW larval feeding, including synthetic insecticides and crop rotation.  The later tactic can be ineffective as a result of behavioral modifications.  The most common insecticide regime is an at planting time application, where the most widely used insecticides have been the organophosphate and synthetic pyrethroid insecticides.  In 2000, these insecticides for CRW control were applied on over 18% of the maize acreage.  This accounted for the largest insecticide usage in any one crop, totaling approximately 12 million pounds of active ingredient targeting CRW.

Recently, a third option has been developed using molecular biological techniques to produce transgenic maize expressing a Bacillus thuringiensis (B.t.) Cry3Bb protein. The Cry3Bb protein has been successfully transferred to corn to produce maize resistant to CRW feeding.

This new transgenic management tool has demonstrated superior larval feeding protection over current insecticides and has the potential to greatly reduce the amount of insecticides applied in maize cropping systems, thus benefiting the environment and potential adverse effects throughout the manufacturing, distribution and use chain.

This presentation describes the development status of Monsanto’s Cry3Bb expressing maize, including the results of efficacy and safety testing.