Plants have many natural mechanisms to keep insects at bay: repellent or toxic chemicals, thorns, hairs, and tough roots and stems. Seed companies try to tap into these mechanisms when developing crop varieties. But like everything else, there are pros and cons to using resistant varieties.

Resistant varieties will not interfere with other pest-management techniques such as crop rotation or, if needed, an insecticide application. They are usually the same price or only slightly more expensive than other seeds. And they may reduce the need for certain insecticide treatments, reducing costs and protecting water quality.