The European corn borer (ECB) is second only to the corn rootworm in importance as an insect pest of field corn. It causes an estimated $ 100 to $250 million in crop losses annually in Iowa alone. Iowa field corn sometimes receives chemical insecticide applications to control ECB if populations are high enough to warrant treatment. Seed corn routinely receives two to three insecticide applications per season to suppress ECB populations. Scouting and properly timed applications of insecticide or Bacillus thuringiensis (known d&Bt), a bacterium that works as a biological control, can manage first generation ECB effectively. However, the ECB has developed an extended egg-laying period, which makes it difficult to control second generations in part because of the difficulty in timing the treatments.