Western Corn Rootworm

The Western corn rootworm, Diabrotica virgifera virgifera, is one of the most devastating corn rootworm species in North America, especially in the midwestern corn-growing areas such as Iowa. A related species, the Northern corn rootworm, D. barberi Smith and Lawrence, co-inhabits in much of the range, and is fairly similar in biology; in the discussion below, many comparisons are made between the two species.

There are two other subspecies of D. virgifera; one, the Mexican corn rootworm (Diabrotica virgifera zeae) is a significant pest in its own right, attacking corn in Mexico.

Corn rootworm larvae can destroy significant percentages of corn if left untreated. In the United States, current estimates show that 30 million acres (120,000 km²) of corn (out of 80 million grown) are infested with corn rootworms and area is expected to grow over the next 20 years. The United States Department of Agriculture estimates that corn rootworms cause $1 billion in lost revenue each year, which includes $800 million in yield loss and $200 million in cost of treatment for corn growers (The Dow Chemical Company).