Insecticidal proteins from Bacillus thuringiensis protect corn from corn rootworms

Field tests of corn co-expressing two new delta-endotoxins from Bacillus th uringiensis (Bt) have demonstrated protection from root damage by western c orn rootworm (Diabrotica virgifera virgifera LeConte). The level of protect ion exceeds that provided by chemical insecticides. In the bacterium, these proteins form crystals during the sporulation phase of the growth cycle, a re encoded by a single operon, and have molecular masses of 14 kDa and 44 k Da. Corn rootworm larvae fed on corn roots expressing the proteins showed h istopathological symptoms in the midgut epithelium.