Category Archives: Pest Group

Have a thrips plan ready for cotton and peanut in 2026

With a good rain today (Thursday May 7), now is a good time to consider your plan for thrips management in cotton and peanuts for 2026.

The first step is to consider how your planting date affects your thrips management, using the thrips risk predictor tool from NC State. This tool forecasts the risk of heavy thrips injury to cotton, specific to a given location and target plant date. An example output from the tool at the Tidewater AREC in Suffolk can be seen below. Because the model uses local weather data, the closer to planting you are when you check, the more accurate the model will be. In this example, the model looks very different than when it was checked prior to today’s weather. It will also change significantly for different locations, so it is worth your time to enter your own information. As of May 7, for the Tidewater AREC, cotton planted between 5/9 and 5/12 will be at elevated risk for thrips injury.

Cotton planted into the high risk windows may benefit from the addition of an in-furrow insecticide targeting thrips. You can also recheck the model after planting to target your scouting efforts and determine the need for foliar insecticides. In the above example, if we had planted cotton on 4/29, we would be monitoring it carefully for thrips injury as it emerges and grows. The most consistent economic return on a foliar thrips spray will come from an application just as the first true leaf is visible. The thrips risk model also generates an optimal spray date, as indicated by the red dot on the figure below. This is an underutilized feature of the tool, and we are testing the value of this model output in the 2026 season.

This tool is specifically designed for cotton, but planting date also has an impact on thrips in peanut. In 2025, we found significantly higher thrips pressure and tomato spotted wilt virus incidence in early planted (late April) peanuts relative to mid or late may. Imidacloprid (Admire Pro) in furrow at planting can provide some thrips suppression, but efficacy has decreased over time, and it is likely insufficient for high-risk scenarios. There are other at-plant options including AgLogic and Thimet, but they are more expensive. We are generating more extensive efficacy data for all at-plant options in 2026. For earlier planted peanuts, scout carefully to determine the need for a foliar application in addition to at-plant insecticides.

The next thing to consider is what insecticide to use, if a foliar application is made. In 2025, we identified tobacco thrips populations with reduced susceptibility to Acephate in Virginia (~ 75-79% mortality on average). We are continuing to monitor this situation in 2026. Hemi SC provides excellent control for both tobacco thrips and western flower thrips and is a viable alternative. This product must be applied either in combination with an herbicide or with a non-ionic surfactant to achieve good control. For peanut, Exirel (cyantraniliprole) can provide good control as a foliar application.

One additional consideration for foliar management are differences in species composition. Western flower thrips have histroically been more difficult to manage with acephate. In 2025, we had a higher proportion of western flower thrips in cotton than usual. Look out for future updates on species composition for 2026.

Managing Fusarium Head Blight Risk as Drought Accelerates Wheat Development in Virginia

Update: 4/20/2026. Drought conditions remain moderate to severe across much of Virginia. Although a weather system moved through the state on April 19, most major small grain production areas received little rainfall (<0.1 inch). Combined with the warm temperatures observed last week, these dry conditions are accelerating winter wheat development. Much of the wheat in the Northern Neck, Middle Peninsula, and Eastern Shore has headed or is approaching heading, and some fields have started flowering.

As of April 20, 2026, the risk of Fusarium Head Blight is low across most production regions, although pockets of moderate risk remain. Fields planted no-till into corn residue are at greater risk, especially when susceptible varieties were used. Growers with susceptible wheat planted into no-till corn stubble may still benefit from a timely fungicide application.

Because heat and drought can move wheat through growth stages more quickly than expected, scout fields frequently so fungicides can still be applied at the correct stage, Feekes 10.5.1 (beginning flowering).

–Douglas S. Higgins, Plant Pathologist, Virginia Tech Eastern Shore Agriculture Research and Extension Center

Corn earworm update–August 21, 2025

Pheromone trap data from our cooperators across Virginia are in this Table. Virginia Cooperative Extension Agents Hélène Doughty (Northampton County) and Scott Reiter (Prince George County) reported many corn earworm larvae in soybean fields this week. Scott’s black light trap averaged 9.3 moths per night. With his help, our entomology program put in an insecticide efficacy experiment in Prince George soybean on August 20. The economic threshold calculator for corn earworm larvae in soybean can be found here. Our cypermethrin adult vial tests show 46% dead or down moths after 24 hours exposure time to this pyrethroid insecticide (n = 594 moths tested this season).

Corn earworm/bollworm update–August 14, 2025

Updated corn earworm moth catches from our pheromone trap network are in this Table. Prince George County’s black light had 11 total moths over the past 8 nights, but high numbers were caught in that county’s pheromone trap (averaging 42.5 per night over the past 8 nights).

Today in a project supported by USDA-NIFA Crop Protection and Pest Management’s Extension Implementation Program, our entomology crew sampled cotton in Suffolk, VA with no genetic protection against bollworm and found 14% boll injury due to this pest in the insecticide-untreated plot. There was no boll injury due to bollworm in the insecticide-untreated WideStrike or Bollgard 3 plots.

Soybean Aphids Found in Mid-Season Soybeans

Robbie Longest, Essex County Extension Agent

Carrie Ortel, Extension Soybean Agronomist

Tim Bryant, Extension Entomologist

Recently, soybean aphids have been confirmed at higher populations than typically expected in August. While many folks are scouting for worms and stinkbugs, we also recommend looking for aphids in your soybean fields as well. The key variables to consider regarding managing soybean aphids are the number of aphids per plant and the soybean growth stage. Information from our Pest Management Guide on Soybean Aphids in summary including info on thresholds and sampling are as follows (VCE Field Crops PMG, Publication 456-016):

  1. Number of aphids per soybean plant

The current economic threshold for aphids is an average of 250 aphids per plant, on two consecutive field visits spaced about 5-7 days apart. This is because aphid populations can “crash” quickly due to heavy pressure by natural enemies like lady beetles, parasitic wasps, and fungal diseases. When scouting, choose a “Z” or “W” shaped pattern to cover the entire field and sample at least 20 to 30 plants per field by examining the entire plant, including stems and upper and lower leaf surfaces. Use the aphid/plant average for determining the need for treatment.

  • The soybean growth stage

The threshold of 250 aphids per plant applies to soybeans through the R5 growth stage (3 mm long seed in the pod at one of the four uppermost nodes on the main stem), after which time plants can tolerate 1,000+ aphids with no threat to yield. If an insecticide is applied for aphids, pyrethroids (e.g. bifenthrin, Warrior II, Mustang Max, etc.) can be effective for management, but choosing a more selective insecticide can preserve natural enemy populations and limit future flare ups of aphids or other pests.

More information on soybean aphids can be found from Purdue University here: https://ag.purdue.edu/department/entm/extension/field-crops-ipm/soybean/soybean-aphids.html as well as a recent article published by University of Nebraska-Lincoln here: https://cropwatch.unl.edu/2023/soybean-aphid-scouting-and-management/.

See the Virginia Tech pest management guide for a full list of labeled insecticides for soybean aphids. Please feel free to reach out to Robbie Longest (robbiel7@vt.edu) or Tim Bryant (btim2@vt.edu) with any additional questions.

Corn earworm update–August 7, 2025

The August 2025 corn earworm moth pheromone trap data (to date) can be found in Table 3. Some of the higher catches occurred in Brunswick, Prince George, and Rockbridge, VA. Last month’s data can be found in Table 2. Scott Reiter’s black light trap in Disputanta captured a total of 30 moths this week (6 nights).

We’ve evaluated 470 moths in our cypermethrin vial tests, with 48% dead/down after a 24-hour exposure to this pyrethroid insecticide at the 5 microgram/vial rate.

Corn earworm update–July 31, 2025

Pheromone trap catches of corn earworm (=bollworm) moths are available in this Table. The Prince George black light trap averaged approximately 13 moths per night this week and that county also had high pheromone trap catches. A peanut field at the Tidewater Agricultural Research and Extension Center in Suffolk, VA hit corn earworm larval threshold numbers (8 larvae per drop cloth sample) and we dropped in an insecticide efficacy experiment. We were finding 2.5 bollworm eggs per 100 cotton terminals this week in Suffolk. Our cypermethrin adult vials tests indicate 44% dead or dying moths after a 24-hour exposure to this pyrethroid insecticide (n = 340 moths tested from Suffolk).

Corn earworm (=bollworm) update–July 24, 2025

Corn earworm moth pheromone trap catches started to increase this week in some counties where captures have previously been low. The highest nightly averages were Brunswick (47), Prince George (30), Accomack (20), Greensville (15), Virginia Beach (13), and Southampton (11). Here is the Table. Black light trap catches at Prince George (Disputanta) averaged 3 per night. Cypermethrin vial test results are 53% dead or down moths after a 24-hour exposure to this pyrethroid insecticide at the rate of 5 micrograms per vial (n=178 moths tested). I found a bollworm egg in cotton on July 23 in Suffolk, VA.

Corn earworm update–July 17, 2025

Corn earworm moth nightly pheromone trap catches ranged from zero to 9 per night this week (here is the Table). Black light traps averaged 1.8 per night in Petersburg and 1.3 per night in Disputanta.

In our corn earworm adult vial tests with the pyrethroid cypermethrin (5 micrograms/vial rate), 62% of moths were dead or knocked down after a 24-hour exposure (64 moths from Suffolk, VA have been tested to date). We will continue to provide weekly updates on trap catches and vial test results.