WCR and NCR are found throughout the western and northern Corn Belt - MCR is locally important in the West only, and SCR can be found throughout the U.S. but rarely causes economic damage
Most damaging corn pest, considered to cause more than $1 billion annual loss in North America
More prevalent in fields following corn
Besides corn, there is some larval survival on a few grasses such as foxtails and especially Miscanthus
Most corn rootworms are attracted to corn to lay their eggs and therefore easily managed with a crop rotation that alternates corn with other crops
However, two variations of this life cycle exist:
Soybean variant of western corn rootworm has evolved to lay eggs in fields other than corn, so larvae are present even when a field was not in corn the preceding year
Diapausing variant of the northern corn rootworm has evolved to lay dormant (diapause) in the soil as an egg for additional years before hatching so that larvae may also appear when corn is planted after a break in the rotation
Favorable conditions for increase are moist soils at egg laying and mild winters
Several natural enemies exist, including nematodes, parasites, predators and diseases, but the population rebuilds rapidly
Management selections may be aided by a careful scouting program that monitors adult presence and potential egg laying, allowing rough prediction of a future problem and the need for applying specific control measures
Avoidance using crop rotation
Control of larvae
Use of insecticide at planting to control newly hatching larvae
Use of seed treated with an insecticide
Control egg laying by spraying emergent adults
Best Practices with Pioneer Products
Suppression of larval development by planting genetically modified hybrids such as Pioneer® brand hybrids with the HXX trait.
HXX – Herculex® XTRA contains both the Herculex I and Herculex RW genes.
Herculex® XTRA Insect Protection technology by Dow AgroSciences and Pioneer Hi-Bred. Herculex® and the HX logo are registered trademarks of Dow AgroSciences LLC.