Category Archives: Insect

Corn earworm moth report for July 23, 2020

Prior to this week, corn earworm/bollworm moth counts have been low in southeast Virginia black light traps. For this week (July 17-23), average nightly catches of moths were: Greensville = 7.4; Prince George-Templeton = 0.3; Prince George-Disputanta = 0.7; Southampton = 1.5; Suffolk = 7.4. Thanks to the Virginia Cooperative Extension Agents who are operating traps this season.

We have tested 47 corn earworm/bollworm moths since June 23, 2020 in our pyrethroid resistance monitoring program. Moths are captured in pheromone traps and are exposed to 5 micrograms of cypermethrin inside a glass vial for 24 hours, then rated as dead/down/alive. Untreated controls (in acetone-only treated vials) are also evaluated to correct for control mortality. The average for the past month is 43% moth survival. High survival rates indicate an increased chance of pyrethroid control issues and the need to consider alternative chemistries if a spray is needed.

In a non-Bt corn experiment planted on April 9 at our research farm in Suffolk, VA, we had large corn earworm larvae in the ears last week. Now they have exited the ears and are pupating in the soil. It takes about 10 days for the moths to emerge–this flight out of corn is the one that we are concerned with in crops such as soybean, cotton, peanuts, and vegetables–the moths want to lay eggs on a good food source for their larvae. Please check back with the Advisory for more pest updates and recommendations.

Northern Neck Crops Conference – Warsaw, VA

The 2020 Northern Neck Crops Conference will be held Thursday, Jan. 16 at the Cobham Park Baptist Church, 13829 History Land Hwy Route 3, Warsaw, VA 22572. This year’s conference will include pesticide certification training, updates from FSA, NRCS, and SWCD, and several Specialists and Agents from Virginia Cooperative Extension that will cover a wide variety of topics. We look forward to seeing your there for a great day of learning and interaction with the experts. Lunch will be provided. Agenda detail are below.

Full Attendance to the conference has been approved for Private Pesticide Applicator Recertification in Category 90 & 91, and Commercial Categories 1A, 10, and 60.  The conference has also been approved for 1.0 Virginia Nutrient Management CEU and 4.0 CCA-CEU credits.

9:00 – 9:05           Welcome – Trent Jones, VCE – Northumberland & Lancaster

9:05 – 9:50           Using Cover Crops for Weed Control – Michael Flessner, VCE – Weed Science Specialist

9:50 – 10:35        Market Update Robert Harper, Virginia Farm Bureau -Grain Division Manager

10:35 – 10:40      Irrigation Resources – Julie Shortridge, VCE – Biological Systems Engineering Specialist

10:40 – 10:55      BREAK – Please visit with our sponsors!

10:55 -11:40       IPM Updates – Sally Taylor, VCE – Entomology Specialist

11:40 – 12:35      Weathering the Storm: How to Cultivate a Productive Mindset – Jeremy Daubert, VCE – Rockbridge County

12:35 – 1:15         LUNCH

1:15 – 1:20           Program Updates – Scott Hammond, NRCS – Soil Conservationist

1:20 – 1:25           Program Updates – Brandon Dillistin, NNSWCD – District Technical Manager

1:25 – 2:15           Corn and Small Grain Production Update – Wade Thomason, VCE – Grains Specialist

2:15 – 2:30           Break & Evaluations

2:30 – 3:00           Legal Updates – Robert Christian, Pesticide Investigator – VDACS

3:00 – 3:30           Safety Updates – Trent Jones & Stephanie Romelczyk, VCE – Northern Neck

3:30 – 3:40           Wrap Up & Paperwork

2020 Four Rivers Agricultural Conference – Providence Forge, VA

The 2020 Four Rivers Agricultural Conference will be held Tuesday, Jan. 14 at Providence Forge Recreation Center: 9900 Carriage Rd, Providence Forge, 23140. This year’s conference will include pesticide certification training, several Specialists and Agents from Virginia Cooperative Extension that will cover a wide variety of topics, and others. In addition, you will be able to get your dicamba herbicide certification with training being offered by Don Cline of BASF. We look forward to seeing your there for a great day of learning and interaction with the experts. Lunch will be provided. Agenda detail are below.

Full Attendance to the conference has been approved for Private Pesticide Applicator Recertification in Category 90 and Commercial Categories 1A, 10, and 60.  The conference has also been approved for 2.5 Virginia Nutrient Management CEU and 2.0 Contact hours for DCR Conservation Planner Re-Certification

9:00        Registration Opens/Meet with Vendors

9:30        Welcome

9:35        Controlling your Drops highlighting dicamba and glyphosate– Laura Maxey-Nay, Hanover Ag Agent

10:00     Pesticide Training – droplet size/playdough- Ed Olsen, Henrico Ag Agent

10:30     Pesticide Legal Update – Robert Christian, VDACS

11:00     2nd round of registration for those not needing pesticide recertification credit

11:15     Dicamba Certification – Don Cline, BASF

12:15     Sponsored Lunch/Meet with Vendors

1:00        Agency updates

1:15        Grain Market Update- Robert Harper, Manager, Virginia Farm Bureau Grain Division

1:45        What I learned from Argentina Agriculture, pest control and nutrient management –Paul Davis

2:05        Corn Update and Hybrid Selection, Dr. Wade Thomason, Extension Grain Agronomist

2:35        Break (visit with sponsors)

2:50        Positioning Your Full-Season Soybean for Maximum Yields, Dr. David Holshouser, Extension Soybean Agronomist

3:20        Making insect management decisions now by purchasing seed for next season, Sally Taylor, Extension Grain Entomologist

3:50       Nematode Panel, various specialists will discuss current nematode control practices.

4:50       Adjourn and paperwork

Tri-County Crop Production Conference – Carson, VA

The 2020 Tri-County Crop Production Conference will be held Tuesday, Jan. 14 at the Carson Volunteer Fire Department on 19806 Halifax Rd in Carson, VA. This year’s conference will host several Specialists from Virginia Tech that will cover a wide variety of topics. In addition, you will be able to get your dicamba herbicide certification with training being offered by Don Cline of BASF. We look forward to seeing your there for a great day of learning and interaction with the experts. Lunch will be provided. Agenda detail are below.

9:00 – 9:05          Welcome and Announcements

9:05 – 9:40         Positioning Your Full-Season Soybean for Maximum Yields– Dr. David Holshouser

There are many things we can do to increase full-season soybean yield, but decisions made before planting are the most important.  This presentation will focus on site-specifically positioning your crop to best take advantage of the limiting resources of water, light, and nutrients.

9:40-10:20          Plant disease management – Dr. David Langston

Nematode and disease interaction issues in soybeans.  Update on fungicide and seed treatments available for corn and soybeans.  Common diseases occurring in 2019.

10:20-10:40       Break

10:40 – 11:10    Update on insect pest management – Dr. Sally Taylor

Review of major insect pests in 2019.  Recommendations for preparing for 2020, scouting tips to use throughout the season, and updates on insecticides available for use.

11:10 – 11:40   Small Grain and Corn Update – Dr. Wade Thomason

Review of the latest research in corn and small grain production in Virginia. 

11:40 – 12:00     Getting Started with Irrigation and Irrigation Survey – Dr. Julie Shortridge

Irrigation is not used on a wide scale in Virginia.  This presentation will introduce our new water specialist and a irrigation survey for growers.

12:00 -12:45       Lunch

12:45 – 1:15       Pesticides in VA update – Robert Christian, VDACS

Update on federal record keeping and worker protection standard. Additional information on changes in pesticide labeling for VA.  PPE review for commonly used pesticides.  Changes to paraquat labeling, handling, and training.

1:15 – 1:35         Weed control update – Scott Reiter

Roundup resistant common ragweed is common in our soybean cropping systems.  There are also 4 different herbicide technology systems in play for the 2020 season.  We will cover the options available and the stewardship needed to keep the herbicides on the target crops.

1:35 – 1:55          Cover crops – Mike Parrish

Cover crops have many uses in our production systems.  Soil erosion control, soil health properties, weed control, and moisture retention.  Presentation will cover results from local cover crop plots and impact on these properties.

1:55 – 3:00          On Target Academy – Don Cline, BASF

This session will cover the required training for using dicamba herbicide in post-emerge applications to Xtend soybeans and cotton.  Applicator & recordkeeping requirements, nozzle selection and technology, buffer requirements, weather conditions, and tank mix additives will be explained in detail

Full Attendance to the conference has been approved for Private Pesticide Applicator Recertification in Commercial Categories 1A, 10, and 60. 

Corn earworm pest problems on hemp and results of recent insecticide tests

By: Tom Kuhar (Entomology Professor, Virginia Tech), Kadie Britt (Ph.D. student researching hemp IPM), and Helene Doughty (Entomologist, Eastern Shore AREC, Painter, VA)

Fig. 1. Corn earworm damaging CBD hemp in Virginia. Photo by Kadie Britt.

Corn earworm has become one of the most important pests of hemp, Cannabis sativa, in Virginia and many other states (Fig. 1).  Please see our factsheet on this insect as it relates to hemp: https://www.pubs.ext.vt.edu/content/dam/pubs_ext_vt_edu/ENTO/ento-328/ENTO-328.pdf

Corn earworm can be quite damaging to the seed heads of hemp grown for grain (Fig. 2), but, as we’ve seen recently in Virginia, the pest can also damage hemp grown for CBD oil.  Over the past few weeks, corn earworm densities and damage to CBD hemp has reached very high levels throughout Virginia, and their presence in fields has been associated with increased flower bud rot (Fig. 3). This can result in significant economic damage to that crop. 

Due to strict regulations on pesticide use on hemp, insecticide recommendations for managing this pest are quite limited at this time.  Recently, we evaluated the efficacy of some naturally-derived pesticides that can be legally applied on hemp in Virginia and one naturally-derived (OMRI-certified) insecticide that currently is not allowed to be applied on hemp (Spinosad).    

Fig. 1. Corn earworm damage to grain hemp. Photo by Helene Doughty, Eastern Shore AREC.
Fig. 2. Bud rot on CBD hemp. Photo by Kadie Britt.

Eastern Shore Insecticide Field Trial:

Treatments included:

  1. Gemstar (5 fl oz/A) – which is a nuclear polyhedrosis virus that is specific to the corn earworm species.  The virus causes corn earworm to become sick and die.  Fig. 4. Shows a corn earworm killed by the virus. 
  2. Javelin WG (8 oz/A)Bacillus thuringiensis (Bt) strain kurstaki – bacterial crystalline proteins that kill caterpillars.
  3. Dipel DF (16 oz/A) – Bt kurstaki different formulation
  4. BoteGHA (32 fl oz/A) Beauveria bassiana – entomopathogenic fungi
  5. Entrust (5 oz/A) – Spinosad derived from soil microbes. *cannot legally be applied on hemp in Virginia. 
Fig. 4. Corn earworm killed by virus (Gemstar insecticide). ESAREC 2019. Photo by Helene Doughty.

We evaluated their efficacy in the field on the Eastern Shore of Virginia in a randomized complete block small plot trial.  Hemp plots were sprayed twice (1 week apart) and numbers of live CEW larvae and damage was assessed.  Results are shown in Figs. 5 & 6.  Entrust was the only product that provided effective control of CEW.  Unfortunately, this is the one product that we evaluated that is not allowed to be applied on hemp.  The insecticide Entrust is OMRI-certified however.    

Fig. 5. Numbers of live corn earworm larvae on hemp plants after insecticide treatments at the ESAREC, Painter, VA.
Fig. 6 Corn earworm damage to hemp seeds in the field after insecticide treatments.

Virginia Tech bioassay trial:

Treatments included:

  1. Gemstar (5 fl oz/A) – which is a nuclear polyhedrosis virus that is specific to the corn earworm species.  The virus causes corn earworm to become sick and die.  Fig. 3. Shows a corn earworm killed by the virus. 
  2. Javelin WG (8 oz/A)Bacillus thuringiensis (Bt) strain kurstaki – bacterial crystalline proteins that kill caterpillars.
  3. Dipel DF (16 oz/A) – Bt kurstaki different formulation
  4. Xentari (16 oz/A) – Bacillus thuringiensis , subsp. aizawai , Strain ABTS-1857
  5. BoteGHA (32 fl oz/A) Beauveria bassiana – entomopathogenic fungi
  6. Entrust (5 oz/A) – Spinosad derived from soil microbes. *cannot legally be applied on hemp in Virginia. 

In order to evaluate the efficacy, untreated hemp seed heads were collected from Kentland Farm and dipped in each of the treatments.  Approximately 1 oz of seeds was placed per diet cup and four reps of 10 cups each were set up for the aforementioned six insecticide treatments.  CEW larvae (3rd instar (medium sized) were collected from sweet corn planted at Kentland Farm and were immediately placed 1 larva per cup.  Mortality was evaluated 1, 2, 3, and 4 days after treatment (Fig. 7).  Similar to the Eastern shore field trial, Entrust provided the most effective control of CEW.  However, this trial also included the Bt aizawai product Xentari, which also provided significant control (better than the other products except spinosad.  Xentari is allowed for use on hemp in Virginia.  For best management of corn earworm during this time, apply Bt products on hemp every few (2-3) days in early morning or late evening. Corn earworm must consume the insecticide for the application to be effective, so ensure good spray coverage on plants. Dead worms may not be noticed until 48 hours after first application.

Fig. 7. Percentage mortality of corn earworm larvae placed on treated hemp seeds in a controlled laboratory experiment. DAT refers to days after treatment (insecticide dip).

EVAREC Soybean Field Day is This Tuesday

The Eastern Virginia Agricultural Research and Extension Center (EVAREC) Soybean Field Day is this Tuesday, Sept. 24. The field day begins at 8:45 am and tours will begin promptly at 9:00 am. There are a number of different topics to be discussed, all supported by the Virginia Soybean Checkoff. The 2019 full-season soybean variety test will also be available for viewing. Lunch will be served by Nixon’s Catering. We look forward to seeing you there.

The EVARE is located at 2229 Menokin Road, Warsaw, VA 22572. For more information, contact Dr. Joseph Oakes, EVAREC Superintendent at 804-333-3485.

Group 1 Field Tour Schedule

  • 8:45 – Welcome & Introductions; Load Trailers to ACR 2
  • 9:00-9:20 – Integrated Pest Management Approach for Soybean
  • Dr. Sally Taylor
  • 9:25-9:45 – Food Grade Soybean Breeding
    • Mr. Nick Lord
  • 9:45 – Load Trailers to Y1
  • 9:55-10:15 – The Best Maturity Group for Your Farm
    • Dr. David Holshouser
  • 10:15-10:30 – The Use of UAV in Crop Research and Production
    • Dr. Joseph Oakes
  • 10:35-10:55 – Roundup-Ready and Conventional Soybean Breeding
    • Dr. Bo Zhang
  • 11:00-11:20 – Weed Management in Soybean
    • Dr. Michael Flessner
  • 11:20 – Walk to Seed Lab

Program & Speakers in the Seed Lab

  • 11:40 – Begin Indoor Program
    • Dr. John Fike: VT Forage Extension Specialist – Hemp Production
    • Dr. Mike Evans: VT School of Plant and Environmental Sciences
  • 12:00 – Lunch is Served: Nixon’s Catering

Thank You to Our Field Day Sponsors!

Crabbe Aviation                       Ryan Ellis

Frazier Quarries                      UniSouth Genetics

James River Equipment            Virginia Crop Improv. Assoc.

Montague Farms

Corn earworm update for September 5, 2019

Average nightly black light trap captures of corn earworm moths this week were: Chesapeake=33; Greensville=13; Southampton=10; Suffolk=27. Hanover had 12 per night if averaged over the past 2 nights, but 3 if averaged over the entire week. Here is the table:

In our corn earworm pyrethroid resistance monitoring experiment (adult vial tests), the seasonal average is 36% survival to a 24-hour exposure of 5 micrograms of cypermethrin per vial.

Corn earworm update for August 29, 2019

Nightly corn earworm/bollworm moth averages for reporting black light trap stations this week were: Greensville=22; Prince George (Templeton)=12; Prince George (Disputanta)=10; Southampton=13; Suffolk=32. Please see the link to the table below and also compare this year’s Suffolk, VA numbers to the past several years.

I have seen a large number of corn earworm moths in our soybean at the Tidewater Agricultural Research & Extension Center in Suffolk this week. Remember to scout for larvae and use the threshold calculator for soybean: https://www.ces.ncsu.edu/wp-content/uploads/2017/08/CEW-calculator-v0.006.html

Our pheromone trap catches at Suffolk have also increased and we were able to conduct more adult vial tests for resistance monitoring using the pyrethroid cypermethrin. The average survival for this season is now 37%.

Corn earworm update for August 8, 2019

Black light trap catches of H. zea (corn earworm/bollworm) moths increased at most locations this week. Please see the data table for more information.

We have tested 168 corn earworm moths in our cypermethrin vial tests so far this season, with a seasonal average of 39.5% survival. Here are the results by month (we’ll be conducting more tests throughout August):

We have updated our corn earworm survey of field corn (as a predictor of infestation risk in other crops such as soybean) to include Rockingham County’s 10.8% infested ears. Thanks to all cooperators for their efforts. Statewide average infested ears was 15.3% for 2019. The updated table and map are here: