While presenting at a community garden meeting with growers and gardeners in Boydton, VA this morning (Sept 10), one of them talked about a pest that was creating holes in her sour gherkin cucumbers. I checked it out and it was pickleworm (see photos). Location was Clarksville, VA. This is not good news for our large pumpkin industry in Virginia. This means that at least some of these tropical moths have mead their way from the southern U.S. on storm fronts and are depositing eggs on blossoms of cucurbit host plants like cucumbers, squash, and pumpkins.
Pickleworm holes in gherkin cucumbers – Clarksville, VA September 10, 2025. Pickleworm larva crawling out of infested cucumber.
Larvae bore into fruit where they can cause the fruit to rot in addition to reducing marketability of the fruit. Growers should inspect their fruit and blossoms regularly until harvest. If pickleworm is found, there are many effective insecticides to control it, but the most affordable would probably be a pyrethroid.
Authors: Taylore Sydnor (Ph.D. Student), Alejandro Del-Pozo (Assistant Professor) & Thomas Kuhar (Professor) – Department of Entomology, Virginia Tech
Diamondback moth
Diamondback moth (DBM), Plutella xylostella, is an important pest of brassica crops worldwide including Virginia (Fig. 1). Management of this pest is challenging due to its ability to quickly develop resistance to insecticides. Therefore, integrated pest management (IPM) tactics are strongly desired. Mating disruption has been developed for DBM as an alternative to insecticides. Mating disruption involves releasing high rates of the mating pheromone into fields confusing and/or desensitizing male moths so that they cannot find female moths and mate and produce damaging larvae on the crops. The strategy has worked extremely well for tree fruit moth pests, and is currently being researched by our lab in Virginia for DBM.
Fig. 1. Diamondback moth larva and leaf feeding damage.
Mating Disruption Trials
In the past three years we have tested several mating disruption dispensers and other products in commercial cabbage and broccoli fields in Hillsville and Mechanicsville, Virginia. Similar research has been conducted in North Carolina and South Carolina by our entomology colleagues. Virtually all of our trials have resulted in sentinel trap shut down of DBM moth catch in the middles of commercial brassica fields that have had mating disruption pheromones released (via dispensers) as compared with non-mating disruption (control) fields that had significant moth catch in the fields (Fig. 2). When male moths cannot find females, then there will be little to no DBM larval infestations on the crops. The Trécé Incorporated dispensers (Fig. 3) used in the aforementioned research are not commercially available yet.
Fig. 2. Weekly catch of diamondback moths (mean ± SE) in baited sticky traps placed in the centers cabbage fields treated with mating disruption dispensers (n= 6) vs. controlFig. 3. Trécé Incorporated MESO pheromone dispenser in a cabbage field. Photo credit: Taylore Sydnor.
Although we have tested various dispensers, tablets, and sprayable pheromones, with each demonstrating success for reducing DBM, the only commercial DBM mating disruption product currently available to growers is a sprayable pheromone, Checkmate® DBM-F (Fig. 4). The sprayable product has been around for a while, but not heavily used by commercial growers probably because of the plethora of effective lepidopteran insecticides that have hit the market in the past 25 years. However, with DBM populations developing resistance to virtually all of the insecticide classes, mating disruption is now a more attractive option for managing this difficult pest.
Fig. 4. CheckMate DBM-F mating disruption product from Suterra.
In 2024, we tested Checkmate® DBM-F in commercial cabbage in Hillsville, VA (4 treated fields paired with 4 control fields), then later in the fall in 2024 in broccoli in Mechanicsville, VA (1 treated field and 1 control field).
Fields were sampled from July to August. Growers were encouraged to maintain their spray regimens to maintain homogeneity between field plots. All treatment fields in both locations were treated with Checkmate at a rate of 2 fl oz/acre approximately every 30 days. Three pheromone-baited delta sticky traps were placed equidistant in each field plot to monitor the DBM moth activity and were checked weekly. In Hillsville, we found that Checkmate® DBM-F was not significant in reducing DBM populations when compared to the control fields. However, during this trial there was a lot of rain, 5.34” over a two-week span, that likely reduced the efficacy of the sprayable pheromone to last in the field. In fairness, the company does recommend re-applying the product after rain events. See the following blog from Suterra that addresses the different rates and frequencies: https://www.suterra.com/blog/checkmate-dbm-f-flexible-spray-timings-for-diamondback-moth-control
This was not possible given the amount of rain that occurred during that 2-week stretch. We felt a more fair assessment of the product occurred with our test in Mechanicsville, where we found that DBM adult captures were significantly shut down in fields treated with Checkmate® DBM-F when compared to control plots (Fig. 5). Overall, we conclude that Checkmate® DBM-F has the potential to be effective in reducing DBM pest populations when applied at the proper conditions. Growers need to be mindful of rainfall after application.
Fig. 5. Weekly catch of diamondback moths (mean ± SE) in baited sticky traps placed in the center of broccoli fields treated with CheckMate DBM-F vs. control.
Over the past three years, we have tested several types of mating disruption dispensers and products for DBM, and have consistently achieved sentinel trap shut-down (= effective control) of the pest in cabbage and broccoli fields in Virginia. We encourage growers to try this innovative strategy for controlling this very difficult pest. Please feel free to contact us if you are interested in trying mating disruption for DBM in Virginia.
Corn earworm is one of the most important pests of agricultural crops in Virginia feeding on corn, cotton, beans, tomatoes, and other crops. Often cold winters lead to high mortality of pupa in the soil and most CEW moths coming from more southern locations. Typically, we don’t see much moth activity and pest pressure until mid-July. But this spring we have seen some unusually high corn earworm moth activity at pheromone traps for this early in the year. Sweet corn grower Mr. Bill Tiver from Halifax Co. (near the North Carolina border) reported >30 moths in one night at his trap on May 26, 2025. Helene Doughty caught 50 moths at a trap in Northampton County this week. Delaware traps also are catching high numbers for late May based on recent correspondence from David Owens. This probably is the result of high overwintering survival of CEW pupa in Virginia or North Carolina soils and pupation already occurring. This could mean the start of a bad year for corn earworm, but so much of this depends on CEW moth flights rolling in from the South on prevailing winds during the summer. We shall see, but it would behoove you to monitor for CEW and keep tabs on this pest if you grow susceptible crops like sweet corn, soybeans, tomatoes, and others.
Corn earworm moths caught in Halifax Co. Virginia May 26, 2025. Photo: Bill Tiver.Corn earworm larva in sweet corn at harvest. From Blacksburg, VA, August 2024.
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
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.).
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.
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.
Commercial vegetable producers have a new tool to assist with integrated pest management (IPM) of diseases and insects in vegetables. MyIPM for Vegetables is the newest resource in the MyIPM app series (https://myipm.app/) for smartphones and smart devices. It currently includes modules for diseases and insects of cucurbits and tomatoes, and additional vegetable crops are planned to be added in the future. Modules contain images and descriptions of diseases and insects; information on available chemical, biological, and cultural management methods for each disease/insect; and tables of labeled fungicides and insecticides that include active ingredients, product names, FRAC/IRAC codes, efficacy, application rates, preharvest intervals (PHIs), and restricted-entry intervals (REIs). Links to additional resources may also be included.
App content is focused on commercial vegetable production in the southeastern U.S., but users outside the southeastern U.S. and home gardens may also find information in the app useful. The development of MyIPM for Vegetables content was led by vegetable entomology and plant pathology specialists from universities within the southeastern U.S. who are part of the Southeastern Vegetable Extension Workers (SEVEW). The SEVEW are also responsible for the popular Southeast U.S. Vegetable Crop Handbook (www.vegcrophandbook) that has been a key resource for commercial vegetable producers in the southeastern U.S. for over 20 years. Author and image credits for specific disease or insect profiles and pictures are available at http://myipm.app/vegetabltes.
MyIPM for Vegetables is not intended to replace product labels. It is meant to be a tool to help vegetable producers make informed IPM decisions. Pesticide users should always read and follow label instructions prior to use. Product labels may change. Product rates may differ depending on the site of application (e.g., field or greenhouse) or type of application (e.g., foliar-applied or soil-applied. Check product labels for additional instructions, precautions, and/or restrictions not listed in the app. Also, check the state registration status of products prior to purchase and use; products may not be registered for use in all states.
MyIPM for Vegetables is free to download for Apple (Apple Store) and Android devices (Google Play). Content is downloaded directly to phones/devices; an Internet connection or cellular signal is not required to access content once it is downloaded. Updates, however, do require an Internet connection or cell signal, and notifications will pop up when updates for downloaded modules and the appropriate Internet/cell connection is available. The MyIPM series began with MyIPM Fruit & Nut that was originally developed by Clemson University in 2012 for peaches and strawberries; the app has since expanded to include other small fruits, tree fruits, and pecans. Other apps in the series include MyIPM Row Crops and MyIPM Hawaii. The Southern Region IPM Center maintains the databases for the MyIPM series apps.
Acknowledgement
This work is partially supported by the Southern IPM Center (Project S23-043) as part of the USDA National Institute of Food and Agriculture Crop Protection and Pest Management Regional Coordination Program (Agreement No. 2022-70006-38002).
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Prepared by Dr. Rebecca A. Melanson, Associate Extension Professor, Plant Pathology, Central Mississippi Research and Extension Center; Dr. Thomas Kuhar, Department of Entomology, Virginia Tech; Dr. Tom Bilbo, Coastal Research and Education Center, Clemson University; and Ms. Inga Meadows, Department of Entomology and Plant Pathology, North Carolina State University.
EPA has finally issued a statement on the revocation of tolerances for chlorpyrifos. For this year, 2024, chlorpyrifos can be used on all product labeled crops. In 2025 and beyond, it will only be allowed on 11 specific crops; alfalfa, apple, asparagus, cherry (tart), citrus, cotton, peach, soybean, strawberry, sugar beet, and wheat (spring and winter). However, there will be further state restrictions on those 11 tolerances coming soon (e.g. chlorpyrifos will only be allowed on tart cherries in MI).
———- Forwarded message ——— From: U.S. EPA Office of Chemical Safety and Pollution Prevention oppt.epa@public.govdelivery.com Date: Fri, Feb 2, 2024 at 1:23 PM Subject: EPA Update on the Use of the Pesticide Chlorpyrifos on Food To: dlfrank@vt.edu
EPA Update on the Use of the Pesticide Chlorpyrifos on Food The U.S. Environmental Protection Agency (EPA) is issuing an update on the use of the pesticide chlorpyrifos on food.
Chlorpyrifos is an organophosphate insecticide used for a large variety of agricultural uses, including soybeans, fruit and nut trees, broccoli, cauliflower, and other row crops, as well as non-food uses. In a final rule issued in August 2021, EPA revoked all tolerances for chlorpyrifos, which establish an amount of a pesticide that is allowed on food. This action effectively stopped the use of the pesticide chlorpyrifos on all food and animal feed. EPA took this action in response to an April 2021 order from the U.S. Court of Appeals for the Ninth Circuit for the Agency to issue—within 60 days—a final rule addressing the use of chlorpyrifos in food or feed crops, without taking public comment or engaging in “further fact-finding.”
That tolerance revocation rule was challenged by a chlorpyrifos registrant and several grower groups in the U.S. Court of Appeals for the Eighth Circuit. On November 2, 2023, the Eighth Circuit issued a ruling vacating EPA’s final rule and sending the issue of chlorpyrifos tolerances back to EPA for further proceedings. The ruling did not include a timeframe or specific instructions for EPA to take a final action on the use of chlorpyrifos in food or feed crops without public comment. EPA is issuing a technical correction in the Federal Register that changed the Code of Federal Regulations to reflect the Eighth Circuit’s decision. The Eighth Circuit’s mandate issued on December 28, 2023, finalized the court’s judgment and vacated the Agency’s 2021 rule revoking chlorpyrifos tolerances.
Since the tolerances are currently in effect, growers can now use currently registered chlorpyrifos products on all crops with reinstated tolerances, consistent with directions for use on those product labels. However, such uses may be subject to restrictions by individual states.
The Eighth Circuit’s decision stated that EPA should have considered modifying the tolerances in addition to complete revocation and noted that the Agency had “identified 11 specific candidates” of food and feed crop uses whose tolerances could be modified in a Preliminary Interim Decision EPA issued in 2020. Thus, the Agency expects to expeditiously propose a new rule to revoke the tolerances for all but 11 uses with additional restrictions for geographic location and rate of application to address safety of the tolerances, and potential restrictions for farmworker and other vulnerable populations, and vulnerable species and their habitats. Those 11 uses are: alfalfa, apple, asparagus, cherry (tart), citrus, cotton, peach, soybean, strawberry, sugar beet, wheat (spring), and wheat (winter). These 11 uses were identified in the December 2020 Chlorpyrifos Proposed Interim Decision and represented about 55% of the total chlorpyrifos usage (average annual pounds applied) on agricultural commodities between 2014-2018.
EPA is also engaged in discussions with registrants of chlorpyrifos products to further reduce exposures associated with these 11 uses of chlorpyrifos. EPA will also consider the 2020 Proposed Interim Decision and public comments received on that document. At this time, any existing final cancelation orders, including any terms for sale, distribution, and use of existing stocks of products subject to those cancelation orders and related return programs for chlorpyrifos products, remain in place, unless and until amended by EPA. EPA will continue to update the public as it evaluates and takes any actions related to chlorpyrifos use. For more information, view the Federal Register Notice.
