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Posted 14 June 2010. PMN Crop News.

Pressure from Black Cutworms Leading to Heavy Feeding, Cutting in Cornfields

Source: Dow AgroSciences Press Release.

Indianapolis, Indiana (May 20, 2010)--Intense moth flights have led to heavy black cutworm (BCW) feeding in many parts of the country. All growers should be scouting their fields diligently for damage from this insect. Only hybrids containing HERCULEX® Insect Protection already have a built-in defense from BCW.


"HERCULEX protects seed investments throughout the season by providing broad-spectrum insect control, including protection from BCW," says Duane Canfield, marketing specialist for Dow AgroSciences traits and germplasm licensing. "In a season with heavy pest pressure, HERCULEX helps give growers peace of mind their yield is protected."

Pressure from other insects, cool weather and partial delayed planting in some areas this spring is intensifying the damage caused by BCW, especially in hybrids without HERCULEX.

"For growers who are just getting back into planting after some wet weather, the BCWs are getting a head start. And the bigger they are, the harder they are to kill," says Travis Belt, Mycogen Seeds customer agronomist. "It will take more feeding on HERCULEX corn to have an effect on the larvae, which can lead to more damage."

Only hybrids containing HERCULEX® Insect Protection, including new SmartStax™ hybrids, provide in-plant protection from BCW, but it is still important for growers who planted corn hybrids with HERCULEX to be scouting their fields to understand all the pressures their crop is facing, not just BCW.

According to Wayne Bailey, a professor of plant sciences at the University of Missouri, cornfields that have been damaged by BCW are sporadic, but many of those fields have reached damage levels above the economic threshold for treatment. Moth captures continue in Illinois, too, and some fields are already being treated, as reported by the University of Illinois in the May 7, 2010, issue of The Bulletin.

Insecticide treatment may be recommended in late-planted corn or in fields where the corn is suffering from other pressures, such as cool weather or heavy pressure from other insects if BCW thresholds are reached. Consult a local crop adviser or university resource to determine the threshold for treatment in your area.

Once corn has reached the four-leaf stage of development, the threat of BCW cutting is reduced, but until that time, growers should be scouting their fields two to three times per week.

"Usually by early June the threat from BCW will be over," Belt says. "But it looks like we are going to deal with it through May; it’s a threat today."

Growers who planted hybrids with HERCULEX XTRA have season-long protection from other pests such as northern, western and Mexican corn rootworm; European corn borer and western bean cutworm, so even after the BCW threat has passed, corn remains protected from these insects all season. To learn more about the value of hybrids with HERCULEX, visit

SmartStax multi-event technology developed by Dow AgroSciences and Monsanto.

®HERCULEX and the HERCULEX Shield Logo are trademarks of Dow AgroSciences LLC.

SmartStax is a trademark of Monsanto Technology LLC. B.t. traited products may not be registered in all states. Check with your seed representative for the registration status in your state.

HERCULEX Insect Protection by Dow AgroSciences and Pioneer Hi-Bred.

©2010 Dow AgroSciences.

Casey Mattke