Douglas S. Higgins, Assistant Professor and Extension Specialist, Virginia Tech Eastern Shore Agriculture Research and Extension Center
In Virginia, wheat is currently at varying growth stages across the state. Many fields are at the boot stage (Feekes 9) or beginning to head (Feekes 10.1 to 10.3), while in some areas and in early-maturing varieties heads are fully emerged (Feekes 10.5).
For those choosing to make a fungicide application, the optimal timing for managing scab is at early flowering (Feekes 10.5.1) and up to seven days afterward (see figure below). Reminder: Do not use products that contain strobilurins (FRAC 11) to manage scab.
Warm, humid, and wet conditions leading up to and during flowering favor infection by the scab-pathogen. As of April 25, 2025, conditions in Virginia are not favorable for disease development in flowering wheat. However, for fields expected to flower in the coming days or weeks, monitor your local weather closely and consult the Fusarium Risk Tool (https://www.wheatscab.psu.edu/) for updates on disease-conducive conditions.
Allium Leafminer (ALM) (Phytomyza gymnostoma), first detected in the U.S. in 2015, has spread through the Northeast, affecting onions, garlic, leeks, chives, and shallots. Detections have been made in VA over the past few years. To date the pest has been detected in the following localities: Frederick, Montgomery, Carroll, Nelson, Northampton, Botetourt, and Bedford counties, plus the City of Lynchburg. If you see oviposition injury, please report it through this form so we can make an accurate map of the pest distribution in VA.
Allium leafminer adult fly. Photo by Grace Stern
Growers should inspect crops for neat rows of small white spots on leaves, indicating feeding and oviposition. Initial infestations often occur on the tips of leaves, with adults visible near leaf tips in cooler conditions. To manage ALM, use floating row covers and apply insecticides as needed. Entrust, works well for organic growers. An integrated pest management (IPM) plan, including monitoring and timely intervention, is essential to reduce ALM’s impact and ensure a successful harvest. For more information, contact your local extension office or visit relevant resources.
Alllium leafminer oviposition marks. Photo by Grace Stern
First, I would like to introduce myself. I am Tim Bryant, the new assistant professor of entomology and extension specialist at the Tidewater AREC, in Suffolk, VA. I did my master’s degree here at the TAREC under Dr. Sally Taylor, and I am excited and grateful for the opportunity to come back and work with the farming community in Virginia. I am also looking forward to continuing to provide updates on this platform as regularly as we have updates to provide. Now, on to a quick update from my first few weeks on the job…
Soybean aphids have been reported in Mecklenburg and Prince George counties (First reports 8/28). Aphids can reproduce asexually, and are capable of rapid population growth under the right conditions, so close monitoring is important. Our threshold for managing soybean aphids is 250 per plant at R4 (full pod) or prior, and 1000+ at R5 (beginning seed) and beyond. The below image shows 300 aphids on a single leaflet as a point of reference (Photo credit: Roger Schmidt, University of Wisconsin-Madison, Bugwood.org). There is likely to be multiple developmental stages of aphids present at one time, and early stages are very small.
There are a couple key considerations for managing aphids; 1) they are highly susceptible to population crashes from natural enemies or weather events, and 2) broad-spectrum insecticide applications (i.e. pyrethroids) may kill aphids, but also the afore-mentioned beneficial insects. Eliminating beneficials can potentially flare up spider mites or other pests later on. If you think you may have an aphid problem, scout several areas of the field to estimate the number of aphids per plant and pay close attention to the number of beneficial insects present. Where we scouted for aphids, there were also large numbers of lady beetle adults and larvae, which are excellent aphid predators. If you reach the aphid threshold, sample again in 5-7 days to ensure the population has not crashed. Narrower spectrum insecticides (e.g. sivanto) may preserve some beneficial insects if an application for aphids is made. See our pest management guide (beginning on page “4-62”) for more details on labeled products, application rates, etc.
The below image shows a lady beetle larvae, which were found in abundance along with the aphids we are reporting on here, feeding on an aphid (Photo credit: Winston Beck, Iowa State University, Bugwood.org).
I have heard from several growers and county agents that they have been seeing a lot of moldy ears lately. Unfortunately, the drought in June followed by wet conditions in July and early August set the stage for ear rot fungi to infest corn this year. Ear rot diseases are Aspergillus ear rot, Diplodia ear rot, Fusarium ear rot, Gibberella ear rot, Penicillium ear rot and Trichoderma ear rot. Pictures and symptoms and signs of each are below.
Aspergillus ear rot
Image by A. Robertson
Diplodia ear rot
Image by G. Munkvold
Fusarium ear rot
Image by A. Robertson
Starburst kernel pattern from Fusarium ear rot
Image by Pioneer Seeds
Gibberella ear rot
Image by A. Robertson
Penicillium ear rot
Image by A. Robertson
Trichoderma ear rot
Image by G. Munkvold
Damage Caused by Ear Rots
The most obvious losses due to ear rots are to yield and quality. Probably the biggest concern with ear rots is that some of them produce mycotoxins that harm humans and livestock. Mycotoxin producers are Aspergillus ear rot (aflatoxin), Fusarium ear rot (fumonisin), Gibberella ear rot (deoxynivalenol or DON) and to a lesser degree Penicillium ear rot (PR toxin and Ochratoxin A). Grain cannot be sold for food or feed if aflatoxin levels are 20 ppb (parts per billion), fumonisin levels cannot be higher than 30-50 ppb and DON no higher than 5 ppb.
Assessing Damage
Growers should hand pick 100 ears of corn from a representative area of a field and shuck them. Pick out 10 ears showing the worst ear rot damage. Place these ears side-by-side to assess the average amount of kernel damage. If more than 25% of the kernels on these 10 ears are damaged, you have a problem. If less than 25% of kernels on the 10 worst ears are damaged, check the field again after a rainfall event and plan on harvesting early. Harvesting at more than 20% moisture and drying to less than 15% moisture will significantly reduce harvest losses when compared to waiting for the corn to dry on its own in the field. The extent of the problem can be determined by shelling all 100 ears, mixing the grain thoroughly, and sending a sample (usually 5.0 lbs) to a reputable mycotoxin testing facility. Don’t mix grain from a field affected by ear rots with grain from a field that has not been affected.
What to do if You Have 10% or More Affected Ears
Harvest early at higher moisture and dry to below 15% moisture
Adjust combine to discard light or damaged kernels
Clean harvest equipment between affected fields and clean fields
Segregate poor quality grain from good grain
Store affected long-term grain at less than 13% moisture and 30°F or below
By: Tom Kuhar, Alejandro Del Pozo, and Katlyn Catron.
Summer storms moving up from the South often bring pests with them. Fall armyworm (FAW) is definitely one of them, and true to form, this tropical moth pest has shown up around Virginia, causing problems in various crops as well as turfgrass. We noticed FAW attacking whorl-stage sweet corn in Blacksburg three weeks ago, and recently have heard reports of problems in Richmond and Appomattox. Other colleagues have documented the presence of FAW in Williamsburg and the Hampton Roads. Fall armyworm is a tropical moth native to warm climate areas of the western hemisphere. It cannot successfully overwinter in Virginia, but frequently makes its way to our state by flying at high altitudes where populations get carried northward on wind fronts. Turfgrass, pasture grass, late planted sweet corn and sorghum, and fall small grains plantings can be particularly at risk to damage from this pest.
Fig. 1. Fall armyworm damage to turf in September 2021. Fall armyworms in turfgrass.
Crops at risk. This pest seems to have a very wide host range, with over 80 plants recorded, but clearly prefers grasses. In addition, field crops also can be attacked, including alfalfa, barley, Bermudagrass, buckwheat, cotton, clover, corn, oat, millet, peanut, rice, ryegrass, sorghum, soybean, sugarcane, timothy, tobacco, and wheat. When the larvae are very numerous, they defoliate the preferred plants, acquire an “armyworm” habit and disperse in large numbers, consuming nearly all vegetation in their path. Just like a battle front, FAW damage appears in a characteristic progressive line across grass plantings (Fig. 1).
Monitoring. Because of the unpredictability of pest pressure from year to year and throughout the season, the use of pheromone traps to monitor local presence and build-up of FAW levels of these moth pests is strongly recommended. Pheromones are natural compounds that are emitted by female FAW moths to attract male moths (Fig. 2) for mating. Synthetic compounds that mimic natural FAW pheromones, often referred to as lures, are placed in traps to attract and trap male moths to inform farmers if FAW is present in their fields and if there is a need for increased scouting. Funnel or bucket (unitrap, universal trap [see Fig. 3]) is the preferred trap for FAW moths. We are monitoring FAW in different locations around Virginia and have caught moths at all locations (Fig. 4).
Fig. 2. Fall armyworm adult moth. Fig. 3. Bucket trap for monitoring FAW moths. Fig. 4. FAW moth caught in trap this week in Williamsburg, VA.
In-field scouting for turfgrass. If you are unsured that you might have an active FAW infestation, you could use the soap flush method, to drench a designated area and disturb the caterpillars that are present. Below are suggested steps to conduct a step-by-step soap flush drench.
What do I need to scout for FAW?
– 03 gallons of water per lawn
– Liquid dish soap (our suggestion is to use a lemon-scent soap)
– Measuring utensils
How do I start?
– Mix 3 tablespoons of the dish soap in one gallon of water
– Then pour one gallon of the soap solution over 2 squared-foot area of the lawn
What is next?
– Spend at least 5 minutes observing the areas of the lawn where you pour the soap water
– Be patient, it takes some time for these caterpillars to move up from the thatch, since the dish is an irritant for them
– There will be several insects and other arthropods crawling out from this area
– Remember to look for caterpillars with the “Y” suture on the front of their heads to confirm the presence of fall armyworms
– Repeat this drench technique in a total of three different spots in one lawn
Control. Most fall armyworms that established in Virginia will die naturally from diseases, parasitoids, and predation, and virtually none will make it through the winter., Nonetheless, masses of larvae can cause significant feeding damage to turfgrass in just a day or two, and thus quick mitigation is sometimes needed to stop their attack. This invariably involves insecticide applications. A wide range of products are available for control of FAW, but resistance to certain insecticides has been reported in some populations and control of large larvae is sometimes difficult with any insecticide. Pyrethroids appear to still be working well on FAW as well as most of the newer lepidopteran-targeting insecticides like diamides (i.e., Acelpryn in turfgrass, Coragen and Vantacor in agricultural crops) and spinosyns (Radiant, Entrust, Blackhawk in ag crops, Matchpoint in turfgrass etc.).
A few disease issues have popped up within the past week on peanuts and soybeans. Some are pretty routine and some are not…
Peanuts
As you may expect, the wet, humid weather has been favorable for peanut diseases like leaf spot, southern stem rot (white mold) and Sclerotinia blight, but especially leaf spot. Sclerotinia is moving slowly due to the warmer weather over past two weeks, but with highs in the 70s today and possibly going forward I expect it to move faster. I have observed Sclerotinia blight in my trial plots. This late in the game I prefer Omega 500 for Sclerotinia blight over Miravis + Elatus. Miravis may not perform against leaf spot if there’s any out there already and Elatus is not a good stand-alone product for Sclerotinia. Remember, if you use Omega 500 you must use a leaf spot material with it. With leaf spot, just don’t extend your spray interval beyond 14 days. The leaf spot advisory has shown leaf spot risk to be steadily high and the last effective spray date jumps 2 days every day. If leaf spot is already showing up you may want to use a micronized sulfur product to temporarily arrest leaf spot along with a fungicide that gives residual control. The hot weather we experienced up until now has led to southern stem rot (white mold) showing up in some fields. If this is the case the best products for that are Excalia (3.0 fl oz), Elatus (7.0 – 9.0 oz) or Convoy at 32 fl oz.
Soybeans
Warm humid weather have led to outbreaks of FLS (frogeye leaf spot) and target spot in some fields. Frogeye will show up first in soybeans that have poor resistance to FLS, and some soybean varieties are more susceptible to target spot like AG49XF3. Both diseases can be very similar in appearance but FLS shows up more in the upper canopy and target spot starts in the lower canopy. I have seen pictures of soybeans defoliated from the bottom up by target spot recently. If you sprayed ahead of disease symptoms you shouldn’t have many problems, but you may see target spot start showing up. If you see disease is already there, use products that have an effective Group 3 fungicide that have curative disease activity. Examples would be Delaro Complete, Lucento, Revylok and Topguard or Topguard EQ.
If you have questions or concerns contact me via e-mail at dblangston@vt.edu or use my cell phone at (757) 870-8498.
By: Tom Kuhar and Brian Currin, Department of Entomology, Virginia Tech.
Early sweet has had its challenges this year in Virginia for sure. First the weather. A drought in June was hard on a lot of crops, but definitely corn if you weren’t able to irrigate. Following that up, a series of rainfall events almost every day in some locations for some stretches in July made it hard to spray insecticides on sweet corn in a timely manner. In addition to challenging weather, pest pressure has been unusually high. We are not even out of July yet and corn earworm moth numbers have been higher than usual in central and western Virginia this month in 2024. Moth catch in pheromone traps totaled 192 and 286 moths per trap last week in Montgomery County (western part of the state) and Halifax County (south central Virginia), respectively. That’s pretty high for July. Harvested sweet corn last week from Whitethorne, VA was heavily infested with corn earworms (Fig. 1) and later corn in the whorl stage had higher than usual infestations of fall armyworm (Fig. 2). This pest species usually comes later in the season. This year some early summer storms brought FAW moths from the south to Virginia.
Fig. 1. Large corn earworm larvae in sweet corn in Whitethorne, VA July 20, 2024.
Many sweet corn growers rely on insecticide spray programs to protect their ears from worm infestations. Some corn earworm populations have shown reduced susceptibility to pyrethroid insecticides such as lambda-cyhalothrin, bifenthrin, Hero, Baythroid, Asana XL, etc. Currently the top performing insecticide products with regards to corn earworm control in sweet corn include: Coragen, Coragen Evo, and Vantacor (all contain the same diamide active ingredient). These insecticides are also relatively safe on nontarget organisms like vertebrates, bees, and natural enemies. Beseige and Elevest also include the same diamide active ingredient paired with a pyrethroid. They are very effective, but less safe on beneficial organisms. The spinosyn products Radiant and Blackhawk are also fairly effective as is the old carbamate standby, Lannate LV. This older insecticide has performed well in recent efficacy trials in sweet corn. These are pretty much it when it comes to effective insecticides for sweet corn. All of these insecticides should be used in a rotation with other products. Recent insecticide trials have shown that rotating the aforementioned products with pyrethroids every other spray provides decent control. This may not be the case in areas that are showing high levels of insecticide resistance.
Fig. 2. Fall armyworm attacking sweet corn in Whitethorne, VA July 20, 2024.
Table 1 shows an action threshold for spray intervals based on trap catches of moths. Our moth catch has been high in late July suggesting a short interval between sprays is probably needed.
Table 1. Action thresholds and insecticide spray intervals during silking based on pheromone trap catch of CEW moths using the Scentry nylon mesh trap and Hercon Heliocoverpa zea lure.
Barley yellow dwarf virus (BYDV) is a significant threat to small grains worldwide and is currently impacting winter wheat in Virginia. This virus is transmitted by cereal aphids. In addition to wheat, BYDV can also infect barley and other perennial grassy hosts, including forage crops such as tall fescue. Yield losses to BYDV often do not exceed 30-35%; however, excessive losses have also been reported in some regions.
Our ongoing survey in Virginia is indicating a widespread BYDV infection. Nearly all the samples tested in 2024 have been positive for BYDV. These samples were received from Augusta, Culpeper, Essex, Prince George, Shenandoah, Montgomery, Northumberland, and Nottoway counties.
Symptoms
BYDV symptoms include reddening or yellowing of leaves (starting from the tip and leaf edges), reduced root biomass, and decreased stem height, ultimately affecting yield and grain quality (Fig. 1). These symptoms also resemble those of other conditions; therefore, laboratory testing is needed to confirm BYDV infection.
Once infected, there is no remedy for the affected plants. However, a combination of cultural and chemical approaches can help minimize the risk of BYDV spreading.
Managing weeds and volunteers can eliminate BYDV and aphid reservoirs. Late fall planting provides an opportunity for the young seedlings to evade infestation by aphids that are on the move from reservoirs. Seed treatment with systemic insecticides combined with late planting are expected further to minimize the risk of BYDV infection in the fall.
Infections that occur in the spring are not expected to result in significant losses since plants often outgrow BYDV infection.
Mapping BYDV distribution in Virginia
We are currently investigating the distribution of BYDV in Virginia and evaluating factors that can predict the risk of BYDV incidence. You can contribute to our ongoing research by sending plant samples for BYDV testing; samples will be tested free of charge. Your participation will help us better understand the prevalence and transmission dynamics of BYDV in Virginia, enabling us to develop targeted management strategies to mitigate the risk of BYDV incidence in agricultural landscapes.
Pleasefill out this form and include it with your plant samples.
As most of you know, corn earworm is a devastating pest of many crops in Virginia.
This native moth pest can successfully overwinter as pupa in Virginia when winters are relatively mild. Virginia crops will also get the usual dispersal of moths coming up from the southern states after mid-July that will lay eggs on many crops that flower in late summer.
Last week Mr. Bill Tiver from Halifax County reported 10 moths per night in his corn earworm trap placed on his farm and larvae already infesting some of his earliest sweet corn. In addition, VCE agent Helene Doughty, in Cape Charles, VA on the Eastern Shore recorded high numbers in the corn earworm moth trap placed there. This is definitely some early warnings of a potentially bad corn earworm year. We most definitely had higher than usual insect overwintering success in Virginia this year.
Greetings friends across Virginia. My graduate student, Hannah Swarm, is researching the ecology and management of wireworms in Virginia. Wireworms are the subterranean larval stage of click beetles and can be quite damaging to many crops including potato, sweetpotato, corn, grains, carrot, hemp, to name a few.
For one of her research objectives, we are hoping to document the different species of wireworms that are found in the different regions of the state (Coastal, Piedmont, mountains).
If you happen to have a decent field where we could come visit and dig around the outside perimeter and collect wireworms, we would greatly appreciate it. Please, email us: hannahswarm711@vt.edu and tkuhar@vt.edu. We are collecting during the months of April and May. Many thanks.
