Entomologists: Start Scouting Western Bean Cutworms

Corn growers should start scouting in late July for signs of Western bean cutworm, a potentially yield-reducing pest, two Purdue Extension entomologists say.

First found in Indiana in 2006, Western bean cutworms feed on corn, legumes and dry beans, such as kidney and black beans. Despite the name, they do not feed on soybeans.

The cutworms can be identified by the black rectangles that develop behind the head of the later instars. These are commonly found feeding within the ear in late summer.

Western bean cutworm populations are tracked and roughly estimated each year using pheromone traps placed throughout the state. The traps capture the grayish-white moths, which usually lay eggs on Indiana corn plants in July. Feeding damage can appear a few weeks later.

So far this year, moth captures in northern Indiana are lower than previous years, said John Obermeyer, Purdue Extension entomologist and Indiana trap coordinator. But the number of moth catches does not necessarily give entomologists an accurate number of larvae, and is generally used as a presence or absence tool to initiate scouting.

Larvae begin emergence after a period of warm weather, but extreme conditions, such as last year’s drought and excessive heat, are hard on Western bean cutworm. With the cooler, wet Indiana spring this year, Purdue Extension entomologist Christian Krupke said the insects are likely delayed.

“We’ve had a cool spring, so we’d expect emergence a little later than last year,” he said. “It is likely that the hot, dry weather that we had last year was not good for them.”

In the early stages of development, Western bean cutworms feed on pollen caught in leaf axils of corn plants (where the leaf meets the stem). This is when growers should apply insecticides to fields to prevent further damage. Once the cutworm is inside the husk of the corn plant and begins feeding on kernels, insecticides are no longer effective. When pollen is gone, kernel feeding will begin and continue until the first frost.

According to Krupke, western bean cutworms also are sometimes indirect pests because they can increase the risk of ear rot development in corn plants by feeding on corn kernels. Some ear rots produce toxins that can be fatal if consumed by livestock – especially swine.

“When you take your grain to the elevator, they will test for mycotoxins. If it is over the threshold for that particular toxin, they might reject the whole batch,” he said. “That’s why this insect is a concern, because it makes the fungal pathogen colonize the ear more fully, which in turn raises toxin levels.”

Some Bacillus thuringiensis, or Bt, corn hybrids are very effective in resisting western bean cutworm damage, but growers are urged to check the label of their particular hybrids. Scouting and insecticide sprays are effective as well, but must take place before larvae enter corn ears.

More information about Western bean cutworm scouting can be found here.

Leave a Reply

Insecticides Stories

Crop InputsAgri-Mek SC Miticide/Insecticide Now Registered For Soybeans, Sweet Corn
July 5, 2016
Soybean growers can now use Agri-Mek SC miticide/insecticide for exceptional control of pests. Already trusted by fruit, nut and vegetable Read More
Crop InputsBayer: 5 Reasons We Disagree With Maryland Neonic Ban
April 12, 2016
We’re disappointed that the Maryland legislature chose not to stand up for sound science and the rights of Maryland’s homeowners Read More
Corn Earworm
FungicidesInsects And Diseases In 2016: Early Planting, More Stress
April 4, 2016
First, the good news: If we consider all the issues growers and retailers are facing right now — low commodity Read More
Crop InputsBayer: The Science Is On Our Side In Belt Insecticide Battle
April 1, 2016
You may have seen some media stories about Bayer’s current disagreement with EPA over registrations for our pesticide flubendiamide, marketed Read More
Trending Articles
Heritage Cooperative
Retail FacilitiesKahler Automation Designs State-Of-The-Art Facility For Heritage Cooperative
July 4, 2016
Heritage Cooperative in Marysville, OH, needed an efficient liquid, dry and grain facility to serve the many needs of their Read More
The Andersons Waterloo
ManagementFirst Indiana Facility Certified Under 4R Nutrient Stewardship Certification Program
June 27, 2016
The 4R Nutrient Stewardship Certification Program has announced that The Andersons, Inc.’s Waterloo, IN, facility has been added to its Read More
Food IT
Industry NewsCalifornia Event Will Mix Ag And Tech Professionals To Explore IT Solutions
June 20, 2016
Silicon Valley is hot on agriculture, and an upcoming event in California will bring together the food and tech industries Read More
Monsanto Luling Plant
Eric SfiligojWhat’s Next For Monsanto?
May 31, 2016
For the folks at Monsanto’s headquarters in St. Louis, MO, it has been an eventful few weeks. Back on May Read More
Soybean Plant closeup
Industry NewsMonsanto Rejects Bayer Bid; Open To More Talks
May 25, 2016
Monsanto Co, the world’s largest seed company, turned down Bayer AG’s $62 billion acquisition bid as “incomplete and financially inadequate” Read More
Eric SfiligojPity The Monsanto Haters
May 23, 2016
An old saying goes thus: “Be careful what you wish for. You just might get it.” Given current events, there Read More
Latest News
Illinois Researchers
FertilizerMeasure Of Age In Soil Nitrogen Could Help Precision Ag…
July 26, 2016
What’s good for crops is not always good for the environment. Nitrogen, a key nutrient for plants, can cause problems Read More
Kochia
Crop InputsNufarm Launches New Herbicide for Resistant Kochia
July 25, 2016
Nufarm introduces Scorch herbicide for U.S. farmers and ranchers combating a broad range of troublesome broadleaf weeds. A unique premix Read More
ManagementNew Rabobank Report Calls for Farmer ROI Focus
July 25, 2016
As U.S. row crop farmers brace themselves for a third year of negative margins, Rabobank believes farmers must lower the Read More
Syngenta Sign
Crop InputsBloomberg: Syngenta-Chem China Deal on Track for Regula…
July 25, 2016
Syngenta AG, which has agreed to be taken over by China National Chemical Corp. for $43 billion, said talks with Read More
ManagementGROWMARK Meeting Visit, Company Takeover Updates, and R…
July 22, 2016
Editors Paul Schrimpf and Eric Sfiligoj discuss their recent speaking engagement at GROWMARK’s eastern event, crop protection company merger rumors, Read More
Crop InputsMonsanto: EU Approves Roundup Ready 2 Xtend Imports
July 22, 2016
Monsanto Co. announced today that the European Commission has granted import approval for Roundup Ready 2 Xtend soybeans. This milestone Read More
Syngenta headquarters in Basel, Switzerland
Crop InputsSyngenta Announces Alfalfa Seed Split Off
July 22, 2016
On September 1, 2016, Syngenta will transfer sales and distribution of alfalfa seed to the NEXGROW branded business that is Read More
Dow DuPont
Crop InputsDuPont, Dow Shareholders Approve Merger
July 21, 2016
DuPont and The Dow Chemical Company announced that, at their respective special meetings of stockholders held today, stockholders of both Read More
ManagementLand O’Lakes Announces SUSTAIN Business Unit, Oth…
July 20, 2016
Land O’Lakes, Inc. today announced the formal organization of a new business unit, SUSTAIN, and its leadership. SUSTAIN will focus Read More
Monsanto Luling Plant
Crop InputsReport: Bayer Shareholder Proposes Monsanto ‘Host…
July 20, 2016
One of Bayer AG’s top 20 shareholders said Wednesday it may make sense for the life-science company to launch an Read More
Young Corn Closeup
Industry NewsNew Leaf Symbiotics Snags Former Monsanto Microbials Le…
July 20, 2016
NewLeaf Symbiotics, announced today the appointment of Dr. Janne Kerovuo as Vice President for Research and Discovery.  Dr. Kerovuo comes Read More
Corn and ditch
ManagementStudy: Saturated Buffers Reduce Nitrates From Subsurfac…
July 19, 2016
The Agricultural Drainage Management Coalition (ADMC), Agricultural Drainage Management Systems Task Force and Dr. Dan Jaynes with the National Laboratory Read More
Case sprayer nozzle closeup
EquipmentAgronomists, CCAs, Custom Applicators Invited To FSR Ag…
July 19, 2016
Agronomists, Certified Crop Advisers (CCA) and custom applicators can stay current on agronomy issues on the grounds of the Farm Read More
Soybean Field
LegislationOhio Soybean Association Names Brian Hill Legislator Of…
July 19, 2016
The Ohio Soybean Association (OSA) has announced that State Representative Brian Hill (R-Zanesville) has been named one of two Legislators of Read More
Eric SfiligojThe Latest Monsanto Rumors: A Game Of Tones
July 18, 2016
When companies are engaged in the back-and-forth of the acquisition game, the tone of their various announcements is always important. Read More
Nozzle spray close-up
AdjuvantsWest Central Distribution Introduces New Elite Family O…
July 14, 2016
West Central Distribution recently released a new line of Elite adjuvants to work alongside the new herbicide technologies that combat Read More
Bayer sign
Crop InputsBayer Makes New Offer For Monsanto
July 14, 2016
Bayer AG boosted its takeover offer for Monsanto Co. to about $65 billion in a bid to overcome the U.S. Read More
ManagementAn Update on Water
July 14, 2016
CropLife Editors Eric Sfiligoj and Matthew Grassi discuss agricultural water issues in conjunction with a recent field trip in Ohio. Read More