Late Planting: 10 Key Insects To Watch

Questions are surfacing about the impact of late planting on key insect pests of corn and soybeans, said Mike Gray, University of Illinois Extension entomologist. Based upon the progress of planting this spring, Gray said he can understand the interest.

Here are 10 key corn and soybean insects growers and retailers should keep a close eye on this spring:

1. Western corn rootworms. Western corn rootworm larvae typically begin to hatch during Memorial Day weekend celebrations. Above-normal temperatures for the remainder of May could accelerate this time line, Gray said. In general, late planting tends to reduce the likelihood of economic infestations of corn rootworms.

“During the past few days (May 7 to 11), corn planting has been progressing at a very impressive clip across many areas of the state,” he said. “At this point, unless corn planting is set back again due to a prolonged stretch of wet weather, I don’t believe the slow pace of planting will affect western corn rootworm densities this growing season.”

2. Black cutworms. Fields that have been tilled and planted late this spring are more susceptible to black cutworm injury. Corn is at most risk when planted into fields that have supported dense populations of winter annual weeds. Gray said he has seen many fields that match this description this spring.

“Don’t be lulled into complacency just because a Bt hybrid has been planted,” he warned. “Large infestations of black cutworms (anticipated this spring) can potentially overwhelm certain Bt hybrids. I urge producers to look for early signs of leaf feeding to assess the potential threat of cutting.”

3. European corn borers. Although few growers worry about this pest anymore, Gray said early planting tends to favor the establishment of the first generation. Late planting increases potential problems with the second generation.

4. Bean leaf beetles. Bean leaf beetle establishment is affected by many factors, including their ability to overwinter as adults beneath plant debris in wooded or sheltered areas, Gray said. Although many areas in Illinois experienced very cold temperatures this past winter, snowfall was abundant and likely provided a blanket of insulation.

“As bean leaf beetles break their dormancy and begin emerging from their overwintering sites, they often first fly to alfalfa fields,” he said. “Early-planted soybean fields are most at risk to early-season bean leaf beetle feeding. Because soybean planting will be later this season, I don’t anticipate large economic infestations of this insect this spring. Any early-planted and isolated field of soybeans located near a wooded area is always at risk to bean leaf beetle injury.”

5. Soybean aphids. Soybean aphid densities were very low throughout Illinois in 2010. In fact, suction trap counts in September and October of last year were exceptionally low, Gray said. These sub-economic adult densities led to very few eggs on its overwintering host, buckthorn.

“I anticipate a very weak flight of aphids to soybean fields this spring,” he said. “The late planting of soybeans will further contribute to a downward spiral of aphid densities early in the season. If the summer of 2011 is mild, aphid densities could certainly rebound by late season. The reproductive power of this insect is impressive. A hot summer may result in another “no-show” for this insect.”

6-7. White grubs and wireworms. In general, delays in corn planting negatively affect densities of these soil insect pests. If planting has occurred and seedlings are subjected to prolonged periods of cool and wet soil conditions, increased levels of root injury by white grubs and feeding on below-ground portions of the stem may occur by wireworms.

“As soil temperatures increase, wireworm larvae typically begin to move deeper into the soil profile and away from the seed zone”, Gray said. “Corn that is planted later in the month into soils that are becoming progressively warmer may not experience as much wireworm injury.”

Annual white grubs, such as Japanese beetle grubs, typically complete pupation by late May and early June. Consequently, their potential to injure late-planted corn is greatly diminished the further planting is delayed in May. However, true white grubs have a three-year life cycle and may injure corn root systems all summer long the second year of their life cycle. Accurate identification of grub species is key to their effective management, Gray said.

8-10. Corn earworms, corn leaf aphids, and fall armyworms. Many insects migrate into the Midwest each year. However, it’s a bit too early to determine how the planting may affect densities of corn earworms, corn leaf aphids, and fall armyworms, Gray said.

“Corn may reach the pollination period at a later date in July this season, typically a period of the summer more prone to hot and dry conditions,” he said. “These insects may reach economic densities on corn plants growing under more stressful conditions this year. Time will tell.”

(Source: Illinois Ag Connection)

Leave a Reply

Insecticides Stories

InsecticidesHow To Scout For Corn Earworms In Corn
July 28, 2014
In her weekly report, University of Missouri Agronomy Specialist Jill Scheidt discusses what to look for when scouting for corn earworm. Read More
InsecticidesEPA Grants Besiege Insecticide Additional Approvals
June 18, 2014
EPA has granted additional registration approvals for the use of Syngenta's Besiege insecticide on sorghum, cereal grains and peanuts. Read More
InsecticidesPrevathon Insect Control Approved For Cereal Crops
January 13, 2014
DuPont's Prevathon insect control powered by Rynaxypyr has received U.S. EPA registration for use on cereal crops, including wheat, most other small grains and sorghum. Read More
InsecticidesInsecticides 2014: Insect Pressure, Solutions On The Rise
January 2, 2014
Bt resistance, weather concerns and myriad other issues have led to an increase in both traditional pest pressures as well as new pests. Read More

Trending Articles

ManagementExpert To Discuss Farmland Value, Rent At Farm Science Review
August 18, 2014
While cropland values in Ohio increased in the past two years, they have remained flat in 2014, declining in some cases, according to an Ohio State University agricultural economist. Read More
EquipmentAdvance Your Technology IQ At MAGIE
August 13, 2014
The Midwest AG Industries Exposition (August 20-21) is the place you need to be to see, study and evaluate how new advances in the equipment, operations, crop protection and fertility sectors can help your business prosper. Read More
HerbicidesScouting Key To Next Season’s Soybean Herbicide Program
August 12, 2014
When growing soybeans, growers need to think ahead to stay one step ahead of weeds. That means examining weed threats and evaluating which herbicides work best. Read More
StewardshipMichigan Agriculture Leaders On Toledo Water Ban: We Want To Be Part Of The Conversation
August 8, 2014
Leaders of Michigan agricultural organizations said Thursday that the government should not have a “knee-jerk reaction” based on last weekend’s water ban in Toledo due to fertilizer run-off in Lake Erie. Read More
CropLife 100BRANDT Acquires Lemon Ag Services
August 4, 2014
The acquisition of Lemon Ag fits BRANDT’s aggressive corporate strategy of providing superior agronomic advice and services for customers in central Illinois. Read More
Eric SfiligojThe Resurgence Of Crop Protection
August 4, 2014
Plenty of new offerings over the next few years should see a rebirth for the crop protection products category in terms of market share. Read More

Latest News

CropLife 100Pinnacle Acquires California-Based Retailer
August 29, 2014
Pinnacle Agriculture Holdings will acquire Kerman Ag Resources, Inc., which will operate under Pinnacle's Performance Agriculture brand. Read More
Allied Cooperative Grain Plant
ManagementArcadia Co-op To Merge With Allied Cooperative
August 28, 2014
Allied Cooperative has announced that members of Arcadia Co-op voted in favor of a merger with Allied Cooperative, paving the way for the consolidation which will be effective on December 1, 2014. Read More
InsecticidesBioinsecticide VENERATE Now Registered In California
August 27, 2014
Marrone Bio Innovations' VENERATE is a new tool to help California growers control crop-damaging insect pests, fight the development of insect resistance and reduce pesticide residues on fruits and vegetables. Read More
CropLife 100Two Iowa-Based Ag Co-ops To Merge
August 27, 2014
The Board of Directors and management of United Western Coop, Missouri Valley, IA has completed a merger with Heartland Co-op, West Des Moines, IA, effective September 1, 2014. Read More
FertilizerKoch Expands AGROTAIN Nitrogen Stabilizer Portfolio
August 26, 2014
Koch Agronomic Services, LLC has added two new innovative nitrogen stabilizers to the AGROTAIN product family – AGROTAIN ADVANCED and AGROTAIN DRI-­MAXX. Read More
Seed/BiotechDuPont To Build Two Seed Treatment Centers
August 26, 2014
DuPont has announced construction on two state-of-the-art centers dedicated to developing and testing seed treatment formulations, applications and seed handling techniques in an important step toward bringing new solutions to growers. Read More
Seed/BiotechLoveland Products Acquires A Controlling Interest In Ag…
August 26, 2014
Loveland Products, a subsidiary of Agrium , has announced the company has acquired a controlling interest in Agricen, a Dallas-area agricultural biotechnology company delivering biochemical-based products for efficient and sustainable plant nutrition. Read More
StewardshipUp Close Look At The 2014 Environmental Respect Award W…
August 25, 2014
The 2014 Environmental Respect Award winners were honored recently at the 24th annual event in Wilmington, DE. Read More
Eric SfiligojAg Science Rejection Carries Consequences
August 25, 2014
As innuendo and fear dog the regulatory process, agriculture can’t get the new tools it needs to combat world hunger. Read More
LegislationFarmers Dismayed As New Farm Bill Dumps Direct Payments
August 25, 2014
The threatened end of cash subsidies to the nation’s row crop farmers dates back through at least the last two iterations of national agriculture policy legislation. Read More
MAGIE 2014 ShowStopper
EquipmentJohn Deere Again Wins MAGIE ShowStopper Award
August 25, 2014
For the second consecutive year, John Deere was honored at the Midwest AG Industries Exposition (MAGIE) for its new R4045 sprayer. Read More
CropLife 100GROWMARK CEO To Retire
August 22, 2014
GROWMARK chief executive officer Jeff Solberg has announced his retirement effective September 15, 2014. Read More
InsecticidesDuPont’s Prevathon Approved For Dry Beans
August 22, 2014
DuPont Prevathon insect control powered by Rynaxypyr has received EPA registration for foliar use on dry bean crops, including dried shelled peas and beans. Read More
ManagementNCGA DuPont New Leaders Program Enters Sophmore Season
August 20, 2014
The National Corn Growers Association and DuPont are pleased to announce the second year of the NCGA DuPont New Leaders Program. Read More
FungicidesVerdesian Links Up With Mitsui, Hokusan
August 20, 2014
Mitsui Chemicals Agro, Inc., and Hokusan Co., announced the signing of an exclusive licensing agreement allowing Verdesian Life Sciences global access to its patented technology for suppressing mycotoxin contamination in wheat and barley. Read More
SprayersUniversity Of Illinois Introduces New Spray App
August 18, 2014
University of Illinois Extension has released a new smartphone app for making sprayer-related calculations. Pesticide Spray Calculator, or Spray Calc, Read More
Crop InputsSyngenta Names New Manager Of Federal Government Relati…
August 18, 2014
Laura Wood Peterson has joined Syngenta as manager of federal government relations, based in Washington, DC. Read More
ManagementExpert To Discuss Farmland Value, Rent At Farm Science …
August 18, 2014
While cropland values in Ohio increased in the past two years, they have remained flat in 2014, declining in some cases, according to an Ohio State University agricultural economist. Read More