Are We Going To Have Aphids Or Not?

Soybean aphids

Soybean aphids should be on a soybean grower’s radar every year, says Dr. Erin Hodgson, Iowa State University Extension entomologist. Now that the insects have broken the on-off, every-other-year cycle, experts can no longer consistently predict when, where, or how heavy infestations may be anymore.

“We don’t know what has changed, whether it’s overwintering, places to overwinter, if they just get a good start in the spring in some areas, or something else,” Hodgson explains.

Potassium (K) may even be a factor. A recent survey of field samples in Wisconsin and Michigan, reported in the Better Crops With Plant Feed publication from the International Plant Nutrition Institute, leads to some concern that low soil K levels in soybeans may leave the crop susceptible to soybean aphid. In their conclusion, the study’s authors stated that “aphid infestations can still occur when K nutrition is adequate, but preventing K deficiencies provides at least one degree of protection or insurance against yield loss from soybean aphids.”

Choosing soybean varieties with resistant genes adapted to a specific growing region can lessen the pressure, but soybean fields may still need a foliar insecticide application. And biological predators, in particular lady beetles, may help keep soybean aphid populations from escalating into an infestation warranting insecticide application.

Strong Opponent

If the original cycle were still in play, 2009 should have been a year of heavy infestation. Instead, while some areas required spraying, it was not as bad as previous years, Hodgson says.

The soybean aphid first appeared in the U.S. in the Great Lakes states around 2000. A decade later, it covers nearly all soybean-growing areas in the U.S. and Canada. After overwintering as several generations of eggs and nymphs in the invasive, woody buckthorn plant, winged generations begin moving into soybean fields in June when beans are at the R1 reproductive stage. That’s when your dealership’s scouts and your grower-customers need to get into the fields to scout.

Scouting early and often may prevent an explosive expansion later in the season. Aphids are known for their long-distance summer migration, and for their ability to reproduce. Those that survive a seed treatment or insecticide application just keep multiplying. “It’s important to know that even if a grower uses a seed treatment, it’s not a silver bullet,” Hodgson warns.

A high kill rate with a foliar insecticide treatment — if the threshold warrants the application — also is crucial to success. Aphids tend to rebound from broadspectrum insecticide applications much better than the beneficial insects, and can increase their numbers rapidly in favorable conditions.

“Last year we saw high aphid infestations in late-planted regions and also where the growing season turned relatively cool,” says Paula Davis, Pioneer Hi-Bred senior manager for insect and disease traits. “The buildup time for aphid populations typically is late June through July, but last year it occurred later, from July into September in some places. Illinois especially got hit with later flights of aphids.”

Keep On Scouting

Soybean growers should develop a scouting plan to monitor the crop’s condition throughout the season, whether they employ your staff’s services or do it themselves. Examining multiple places in the field to get an overall analysis and identify problem areas is critical every year, says Travis Belt, Mycogen Seeds customer agronomist.

Hodgson recommends that retailers and growers get out into the field to scout at flowering and continue through seed set. Scout the undersides of new leaflets on a regular basis, preferably weekly but at least every 15 days, to determine how fast the aphid numbers are climbing.

University entomologists have determined that foliar application of an insecticide is needed when the field has reached a threshold of an average of 250 aphids per plant — but not before. “It’s the best way to protect yield and reduce cost,” Hodgson says. “Applying anything below the threshold is a waste of money. Some growers have limited access to equipment, so they get scared and schedule the application early so they get on the schedule — before determining if they’ve reached the treatment threshold. The infestation could be at 100 and never go any higher, for example. That’s very expensive; the cost of fuel, equipment, and product adds up.”

What should your scouts and grower-customers look for? Usually, the aphids will form colonies on the undersides of the plant leaf, especially the newest trifoliates. Hodgson recommends walking through each field, checking 30 plants randomly per 50 acres. “It should take 20 minutes, in and out,” she says. “Count every aphid on the plant and take the average of the 30 plants to determine your count.”

Spray What?

Some of the insecticides approved by EPA for use in controlling soybean aphids this season include:

•  Endigo ZC (lambda-cyhalothrin + thiamethoxam) from Syngenta Crop Protection is formulated with Zeon technology and uses dual modes of action for fast and effective knockdown of key insect pests, including soybean aphids, and long residual control against re-establishing insect populations, yet has minimal impact on beneficial insects.

•  Belay (clothianidin) from Valent U.S.A. Corp. is a third-generation neonicotinoid with a novel mode of action. The highly systemic chemistry provides initial knockdown of soybean aphids after a few hours, and also quickly translocates through the plant for control from 14 days to 21 days.

•  Leverage 2.7 (imidacloprid + cyfluthrin) from Bayer CropScience, now available at a new lower price, provides fast knockdown, extended residual control, and Stress Shield (which helps defend plants from environmental stresses). Two modes of action provide both contact and in-plant protection from a broad spectrum of sucking and chewing pests, including soybean aphids.

•  Cobalt (chlorpyrifos + gamma-cyhalothrin) and Lorsban Advanced (chlorpyrifos) from Dow AgroSciences LLC provide broadspectrum insect control in soybeans.

•  BASF recently signed an agreement with Meiji Seika Kaisah, Ltd. for the co-development of a new insecticide, currently called ME5343. The new class of chemistry and new mode of action show significant efficacy for the control of aphids and certain other insects, especially those that have developed resistance to other insecticides. BASF will submit it for regulatory approval in the U.S. in 2013, with a commercial launch planned for 2015.

Topics:

Leave a Reply

Insecticides Stories

InsecticidesSyngenta Recommends Soybean Scouting To Prevent Economic Loss From Insects
July 22, 2015
Proper soybean insect pest control begins with scouting. As the warm weather continues, Syngenta encourages growers to implement a scouting Read More
InsecticidesVestaron Biopesticide Approved In California
June 29, 2015
Vestaron Corporation, a developer of insect control products derived from naturally occurring peptides, today announced that its VST-006330-EP biopesticide has received Read More
InsecticidesValent’s Zeal SC Miticide Receives EPA Approval
June 29, 2015
Valent U.S.A. Corporation announced today that Zeal SC Miticide has been registered by EPA with a new liquid formulation that Read More
Tim Hassinger Dow AgroSciences President and CEO
Crop InputsDow Details Molecular Forensic Technology For Insecticides
June 10, 2015
Just like each human fingerprint is unique; microbes that have been developed to produce naturally based crop protection products are Read More
Top 100 Articles
Crop InputsLand ‘O Lakes, United Suppliers Finalize Merger
August 24, 2015
According to a press release on August 24, owners of United Suppliers, Inc. and members of Land O’Lakes, Inc. “have Read More
West Central Cooperative, Jefferson, IA
CropLife 100Iowa Cooperatives To Explore Unification
August 19, 2015
The boards of directors at two of Iowa’s leading farmer-owned cooperatives yesterday signed a letter of intent to study the Read More
CropLife 100Southern States Coop Hosting Drone Flight This Friday
August 3, 2015
Southern States Cooperative — No. 9 on the CropLife 100 — is hosting an FAA-approved drone demonstration at Grandview Farms Read More
CropLife 100Aligned Ag Distributors Adds Four New Owners
July 30, 2015
Aligned Ag Distributors LLC has announced the addition of four new customer/owners to Franklin Holding Co. LLC. They are: The Read More
CropLife 100Pinnacle Purchases California-Based Specialty Crops Retailer
July 20, 2015
Pinnacle Agriculture Holdings has successfully acquired California-based NH3 Service Co.  Operating as part of Pinnacle’s Performance Agriculture brand, the new locations Read More
Asmus Farm Supply liquid fertilizer facility features 20,000 square feet
CropLife 100Slideshow: Asmus Farm Supply Shows Off Its New Liquid Fertilizer Facility
July 15, 2015
Asmus Farm Supply, Rake, IA, recently added a new liquid fertilizer facility to its company operations. The new liquid fertilizer Read More
Latest News
StewardshipBee Buffer Strip Initiative Seeks 100 Ohio Farmers
August 31, 2015
The U.S. Bee Buffer Project, an initiative of the Pollinator Partnership (P2), Burt’s Bees and The Burt’s Bees Greater Good Read More
2015 ShowStopper Award, MAGIE
EquipmentA ShowStopper From Case IH: The Patriot 2250
August 31, 2015
For nine years now, visitors to the yearly Midwest AG Industries Exposition (MAGIE) show have been tasked with not only Read More
Crop InputsMonsanto, FMC Expand Roundup Ready PLUS Platform
August 31, 2015
FMC Corp. and Monsanto Co. announced today an expanded agreement to continue their participation in the Roundup Ready PLUS Crop Read More
Deere Nutrient Applicator
Eric SfiligojThe Good & Bad News From MAGIE
August 31, 2015
As I write this column, I’ve just returned from the annual Midwest AG Industries (MAGIE) trade show in Bloomington, IL. Read More
CPS Morenci receiving its 4R certification
StewardshipCPS Morenci Becomes First Michigan Facility Certified I…
August 31, 2015
The 4R Nutrient Stewardship Certification Program has announced that Crop Production Services, Inc.’s facility located in Morenci, MI, has been Read More
EquipmentDeere Announces Soucy Track Distribution Alliance
August 28, 2015
John Deere announces an alliance with Soucy Track to sell and distribute products through the John Deere dealer channel. “This Read More
FertilizerFall-Applied Phosphorus: A Rooted Investment
August 28, 2015
As commodity prices decrease and input prices continue to rise, farmers are seeking more efficient strategies for meeting a high Read More
Monsanto Sign
Crop InputsWhat’s Next For Monsanto, Syngenta?
August 28, 2015
After dropping its $47 billion bid to take over Swiss agribusiness firm Syngenta, Monsanto may be turning its focus to Read More
Golden Harvest Corn stalks
Crop InputsMonsanto: Syngenta Not The Only Horse In Crop Protectio…
August 28, 2015
Monsanto Co, having ditched an audacious $46 billion (£30 billion) offer for Syngenta AG, may downshift to a humbler strategy Read More
ManagementConsolidation hits and a miss; And a look at China’s ch…
August 28, 2015
As Monsanto suspends its pursuit of Syngenta, consolidation news at the retail and distribution level heats up. CropLife magazine’s Executive Read More
Corn Field
MicronutrientsHuma Gro Introduces New Boron Liquid Nutrient Formulati…
August 28, 2015
BORO-MAX, a new boron (B) 10% liquid nutrient formulation, has been added to the Huma Gro product line. This new Read More
Crop InputsNFU: Monsanto Decision To Withdraw Syngenta Bid ‘…
August 26, 2015
National Farmers Union (NFU) President Roger Johnson said the organization was very pleased by the news that Monsanto has withdrawn Read More
Crop InputsMonsanto Withdraws Bid For Syngenta
August 26, 2015
Monsanto Co. abandoned its latest effort to acquire Syngenta AG, the world’s top maker of pesticides, after a sweetened bid Read More
Syngenta Sign
Crop InputsSyngenta Comments On Monsanto Announcement
August 26, 2015
The Board of Syngenta confirms that it received a verbal proposal from Monsanto to acquire the company at a price Read More
Case IH Patriot 2250 Sprayer
EquipmentHigh-powered Case IH Patriot 2250 Sprayer Pushes Throug…
August 26, 2015
Engineered with more muscle, the new 660-gallon-capacity Patriot 2250 sprayer features best-in-class horsepower, along with the fuel efficiency that comes Read More
Crop InputsLand ‘O Lakes, United Suppliers Finalize Merger
August 24, 2015
According to a press release on August 24, owners of United Suppliers, Inc. and members of Land O’Lakes, Inc. “have Read More
TMX-2050 In-Cab Display Launch Run Screen
Eric SfiligojPrecision Ag Could Shine In Increased Spotlight On Agri…
August 24, 2015
By any measure, 2015 is turning into one of the most challenging years agriculture has ever experienced. All throughout good Read More
ManagementCrop Conditions In Minnesota and Traveling Time
August 21, 2015
Editors Paul Schrimpf and Eric Sfiilgoj discuss the crop outlook from a field trip to Minnesota and upcoming travel plans. Read More