The discovery of new B.t. increases the chances that future insecticides may come from the soil, rather than the laboratory. Several of the newly discovered B.t. Patents are now pending on three of the new B.t. It is these very issues that recently prompted the United Nations FAO Commission on Plant Genetic Resources to consider extending its mandate beyond plant genetic resources to include the broader issues of biological diversity. Resistance to B.t.
Crops targeted include tobacco, tomato, corn, cotton, potatoes, sunflowers, citrus, and more.
The good news is that there is a great deal of commercial interest in the development of biological pest controls. One major market for an effective B.t. toxin, for example, is corn. There are a number of strategies that could be adopted to curtail the rapid rate of insect resistance to B.t. Dr. Gould suggests that genetic engineers will someday have the ability to produce crops that express insect-resistance genes only at times and places where they are required. Another approach involves the use of seed mixtures.