March 11, 2016
CRW Quick Facts
- High CRW pressure
is often a result of a
entire crop season
may identify fields
with growing CRW
- Heavy CRW
pressure can develop
due to the creation of a “trap crop” situation that serves
to attract and concentrate adult beetles during the egglaying
period. Corn in these areas the following season
may be subject to extensive damage due to CRW
- A number of environmental and management-related
factors can promote the development of trap crops
- Delays in maturity within areas of a field due to stress
conditions that slow crop development such as
prolonged saturation of the soil that may lead to
nitrogen deficiency. These areas dry down less quickly
and may attract foraging adult beetles later in the
- Late planted, double cropped, or fuller season corn
products (such as corn grown for silage) planted
adjacent to earlier maturing products may serve as a
late season refuge for adult beetles.
- Higher yielding products grown in the vicinity of poorer
performing products may be more attractive as a
habitat and potential food source to a number of
insects, including CRW.
- Anything that delays maturity, such as late planting,
stress due to planting in wet areas, or nitrogen
- Planter longer-season products in fields adjacent to
- High yield potential corn surrounded by lower yield
- Late planting that might expose corn to later emerging
CRW Best Management Practices
Follow recommended Integrated Pest Management (IPM)
practices, including cultural control tactics, scouting, and
the appropriate use of pest thresholds for chemical control
strategies. Implement BMPs in all fields with the probability
of high CRW pressure.
- Consider rotating to a non-host crop such as soybeans
to break the CRW life cycle. Periodic rotation can
benefit each crop in the rotation.
- Plant Genuity® SmartStax® RIB Complete® Corn Blend
products that provide dual mode-of-action (pyramided)
B.t. traits and deliver excellent CRW protection.
- If rotation or Genuity® SmartStax® RIB Complete® Corn Blend products are not acceptable options, consider using soilapplied
insecticides with non-Bt or single mode-of-action products. Planting single mode-of-action technologies such as
Genuity® VT Triple PRO® products or Genuity® VT Triple PRO® RIB Complete® Corn Blend products to manage CRW larvae
and adults is not recommended when less than satisfactory control of CRW was observed the previous season.
Regardless of which primary control tactic listed above is implemented, growers should adopt the following support activities
to maximize success:
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- Employ regular and appropriate scouting techniques.
- Use of a foliar insecticide is recommended if thresholds are reached. In general, potential for yield loss in the following
year’s corn could occur when adult beetle populations exceed 3/4 to 1 beetle per plant during the egg-laying period.
- Control volunteer corn and weedy escapes in soybeans. These plants may attract beetles and encourage concentrated
egg-laying within the non-host crop.
- Select CRW control measures that have a minimal impact on beneficial insects.
- Consult the Genuity® Rootworm Manager or your local agronomist for additional CRW management information
- Read the IRM Grower Guide prior to planting and observe all refuge requirements.