The western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) is one of the most serious crop pests in North America and Europe. WCR feeding causes reduced water and mineral uptake. Yield loss is most severe when water is limiting. Grain from damaged plants is also more likely to be left in the field due to increased lodging of plants with reduced brace root support. WCR are univoltine, with eggs overwintering in the soil. There are three larval instars, with the bulk of the damage being caused by third instar.