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

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
InsecticidesEPA Moves To Cancel The Insecticide Flubendiamide
March 7, 2016
The U.S. EPA is issuing a notice of intent to cancel all Bayer CropScience, LP and Nichino America, Inc., flubendiamide Read More
Trending Articles
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
Monsanto Luling Plant
Crop InputsReport: Bayer Eyeing Monsanto For Possible Mega-Merger
May 16, 2016
Bayer AG is exploring a potential bid for U.S. competitor Monsanto Co. in a deal that would create the world’s Read More
Aerial Drone
Precision AgA Deeper Dive Into The Future Of Precision Ag
May 9, 2016
For about two decades now, through the good and the bad times, the ups and the downs inherent in agriculture, Read More
Latest News
Allen Summers Asmark Institute PSM Training
EmployeesAsmark Institute Sponsors 25 ResponsibleAg Auditor Trai…
June 21, 2016
The Asmark Institute has announced plans to provide 25 scholarships through their affiliated State fertilizer and agrichemical associations to help encourage Read More
Kennebec Elevator
CropLife 100Wheat Growers Celebrates Kennebec Elevator Grand Openin…
June 21, 2016
Over 250 patrons and guests were on hand to celebrate Wheat Growers’ Kennebec Elevator grand opening. South Dakota Secretary of Read More
Land O Lakes
Industry NewsLand O’Lakes To Acquire Ceres
June 20, 2016
Land O’ Lakes, Inc. and Ceres, Inc. have announced that they have signed a definitive merger agreement under which Land O’Lakes Read More
Food IT
Industry NewsCalifornia Event Will Mix Ag And Tech Professionals To …
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
LegislationVilsack Christens WinField Crop Adventure, Talks Monsan…
June 17, 2016
The WinField Crop Adventure grand opening ceremonies at Fair Oaks Farms (near Winemac, IN) welcomed USDA Secretary of Agriculture Tom Read More
Crop InputsFields of the Future: WinField Doubles Down with Agri-E…
June 16, 2016
Land O’Lakes, Inc., joined by Agriculture Secretary Tom Vilsack, today will host Fields of the Future, a live broadcast about Read More
Bayer sign
Crop InputsMonsanto Turns Back Bayer Again
June 14, 2016
Bayer AG’s bid to buy Monsanto Co. for more than $60 billion has hit an impasse that could pose a Read More
Young Corn Field
Crop NutritionNext Generation Of Nitrogen Efficiency Technology Conve…
June 13, 2016
Commodity price projections indicate farmers will continue to face tight margins again this year. Delivering higher yields and more bushels Read More
Industry NewsLa Crosse Seed Acquires Cover Crop Solutions Brand
June 10, 2016
La Crosse Seed announces that it is the new and exclusive owner of the entire family of brands of Cover Read More
ManagementTravel Plans and EU Rejection of Glyphosate, Biotech Cr…
June 9, 2016
Editors Paul Schrimpf and Eric Sfiligoj talk about upcoming trips and the latest in the European Union’s moves against glyphosate Read More
Aspire with Boron
Crop InputsStudy: Aspire with Boron Ups Alfalfa Yields
June 8, 2016
Alfalfa growers are successfully improving yields through the cutting season by applying an important micronutrient. In a recent study, The Read More
Industry NewsAGCO Announces Tragic Death of Longtime Employee
June 8, 2016
It is with deepest regret that we announce the passing of our dear friend, colleague and customer advocate-in-chief Kevin W. Read More
Wheat Field North Dakota
Industry NewsBASF Inks Northern Seed for Clearfield Wheat R&D Li…
June 6, 2016
BASF has licensed Northern Seed LLC to perform research and development of BASF’s proprietary and patented Clearfield technology in wheat. Read More
ManagementBayer/Monsanto, EU/Glyphosate, Corn/Soybeans
June 2, 2016
Editors Paul Schrimpf and Eric Sfiligoj discuss the latest regarding industry mergers, the glyphosate debate in Europe, and an update Read More
Growers looking at soybeans
Industry NewsKoch Licenses 2 Marrone Products For North American Dis…
June 2, 2016
Koch Agronomic Services (Koch), with support from its affiliate, Koch Biological Solutions, has secured exclusive rights to sell REGALIA Rx Read More
Gypsum
Industry NewsBeneficial Reuse Management Launches GYPSOIL BLENDABLE
June 2, 2016
Beneficial Reuse Management (BRM) has introduced GYPSOIL BLENDABLE, a new high-quality pelleted gypsum fertilizer that supplies 17% sulfate sulfur and Read More
StewardshipAgrible Joins Field To Market To Pursue Sustainable Sou…
June 1, 2016
Agrible, Inc. has joined Field to Market: The Alliance for Sustainable Agriculture as an associate member. As a leading multi-stakeholder Read More