The Pee Dee Research and Education Center invites you to learn the most recently findings of research in plant pathology, entomology, soil and crop science in South Carolina.
Come join us in the field day organized at the Pee Dee Rec Field day on August 28th, from 9:00 am to 12:00 pm, and hear from the experts of Clemson university!
It was only a matter of time, given its previous detections in North Carolina and Georgia—and now South Carolina has officially joined the list of states where the invasive Spotted Lanternfly (Lycorma delicatula) has been detected. This phloem-feeding planthopper poses a serious threat to vineyards, ornamental plantings, and tree health throughout the region.
Dr. Muhammad “Zee” Ahmed, Assistant Professor at Clemson University’s Turf and Ornamental Entomology Lab, is actively collaborating with entomologists nationwide through the Multistate Working Group for SLF. His ongoing efforts include:
With a host range exceeding 100 plant species and proven economic damage in the millions—particularly in vineyards—the need for early detection and rapid response cannot be overstated. Dr. Ahmed’s outreach emphasizes careful scouting for SLF egg masses, which can be confused with mud dauber nests, lichens, or other natural debris. Recognizing black sooty mold, branch dieback, and the insect’s distinct nymph and adult appearances are also key.
Management Tactics at a Glance
Dr. Ahmed’s field guide is a critical resource for growers, landscapers, and IPM professionals looking to protect turfgrass, ornamental landscapes, and agricultural sectors from this hitchhiking pest.
To learn more or get involved, contact Dr. Ahmed at mahmed2@clemson.edu.
Mealybugs may be small, but their impact in greenhouse production can be massive. These sap-sucking pests often sneak in as nearly invisible crawlers and quickly establish persistent infestations—nestling behind leaves, burrowing into root zones, and hiding in plant debris. Once entrenched, they can be notoriously difficult to manage.
At the Turf and Ornamental Entomology Laboratory, we’ve seen firsthand how challenging mealybug outbreaks can be for growers. That’s why PhD students Powlomee Mondal and Peilin Tan, under the guidance of Dr. Zee Ahmed, compiled a comprehensive guide to help greenhouse professionals tackle these pests head-on.
What’s Inside the Strategy
In the article, Managing Mealybugs in the Greenhouse, we outline a science-based, step-by-step approach that includes:
This guide is designed to empower growers with practical, research-backed tactics that reduce pest pressure while preserving plant health and minimizing chemical overuse.
Read the Full Article
Mondal, P., Tan, P. and Ahmed, Z., 2025. How to manage mealybugs in the greenhouse. Greenhouse Management, [online] 24 June. Available at: https://www.greenhousemag.com/article/managing-mealybugs-pest-control-greenhouse/ [Accessed 4 Jul. 2025].
Grower Input Needed:
In addition to the article, Peilin Tan is conducting a brief survey to better understand the current challenges and research needs related to mealybug management in greenhouse systems. The survey consists of nine multiple-choice questions and does not collect any personal information.
We would greatly appreciate your participation:
Take the Survey
Figure 1: Scale insects.
Figure 2: Mealy bug species globally, in the USA, and in greenhouses.
Figure 3: Mealybug species considered greenhouse pests.
The combination of warmer temperatures and stress from dry conditions for rainfed fields is a reminder that if our fields have some history of stem rot/white mold disease (Figure 1), we can proactively protect them during our earlier fungicide applications. This can be as simple as adding tebuconazole in with the 45-day spray or coming in earlier 30/35 DAP with Elatus/Excalia/Lucento, or we may also consider swapping fungicides during latter applications for increased control. Not all fields need the extra attention, but it is a helpful tool at our disposal where we are looking for additional management. Likewise, earlier applications are less subject to canopy interference of spray penetration/ground deposition. Rain is our friend for many things including fungicide wash in, but its contribution rapidly drops off with increasing time after application. Two days after an application, rain will help some but is at that point more modest than monumental. Rain-in the day of application or a day after improves wash in, but this often comes at the expense of foliar leaf spot coverage/control. A persnickety predicament, or rather, a reminder of fine tuning one way or another. If we are coming due for an application where soil disease control is a priority and we can wait a day to two/three days to take advantage of a coming rain we can consider doing so, keeping in mind the suggestive rather than absolute nature of forecasts. This is more helpful later in the season when canopy size is larger. However, an application without rain is better than no application at all. We cannot wait indefinitely to take advantage of a possible rainfall, and we do well to keep in mind the importance of effective leaf spot management at the same time, as both our soil and foliar diseases are best managed in a preventative rather than reactive manner.
From work across eleven experiments conducted from 2015 to 2023 evaluating the efficacy of several different fungicides for stem rot/white mold control, maximum label rates of benzovindiflupyr plus azoxystrobin (Elatus) and inpyrfluxam (Excalis) were estimated as conferring the greatest returns over the chlorothalonil-only control (Bravo-only).
Control efficacy of maximum labeled rates of flutolanil (Convoy) and prothioconazole plus tebuconazole (Provost Silver) were also effective in managing this disease. While an application of tebuconazole alone for soil disease control was among the most efficient in terms of % stem rot control per fungicide product application cost, that active ingredient also conferred the least total amount of control at its maximum label rate. This makes tebuconazole an important and efficient fungicide to keep in our overall disease management programs, but other fungicides or tank mix combinations are capable of providing greater control where we could benefit from it due to specific fields having a history of increased white mold disease pressure, weather conditions during the year favoring its development, or application windows preceding a timely rain or irrigation allowing us to capitalize on increased efficacy.
The U.S. cut flower market was valued at approximately 9.2 billion USD in 2021 and is projected to grow to nearly 12.8 billion USD by 2028, with a steady compound annual growth rate of 4.8%. While irises make up a smaller share of this market, their visual appeal and versatility give them lasting economic and cultural value. Some varieties even pull double duty—producing rhizomes used in perfumes and traditional medicine. For South Carolina, ornamental horticulture is more than just aesthetics—it’s a key part of the state’s thriving green industry. Irises—particularly a wide range of native and cultivated varieties/cultivars—play a notable role in this sector, contributing to landscape diversity, wetland restoration, and the ornamental plant trade.
However, iris growers across the region may be facing an unseen threat. We recently discovered a dipteran leafminer, tentatively identified as Cerodontha sp., causing significant damage in iris production areas. A quick survey of major plant outlets in Florence, SC revealed that most Louisiana iris plants were infested, with damage easily mistaken for abiotic stress like overwatering or nutrient issues (Figure 1).
What to Look For:
Detecting and monitoring the leafminer life cycle in your area is the first step in effective management. Many growers have had difficulty managing leafminers, and a key early task is confirming whether the symptoms observed are actually caused by leafminers. This involves locating mines and inspecting them for visible life stages such as larvae, pupae, or empty trails. Misdiagnosing the symptoms or mistiming treatments can significantly reduce control efficacy, especially when insecticides are applied during periods when the pest is in the egg, pupal, or inactive larval stage—times when it’s least vulnerable and least exposed to control measures.
If you find damage on your irises:
Please contact Dr. Zee Ahmed at mahmed2@clemson.edu or (352) 283-0173 for support with identification and management.
The Clemson University Cotton/Soybean Insect Newsletter is in its 20th year of distribution/circulation to stakeholders needing regular and timely information about important arthropod pests of cotton and soybeans in South Carolina and the southeastern USA. The newsletter includes information from contributors (Extension agents, consultants, industry reps, etc.) about the situation in their areas of the state, weekly observations in cotton and soybeans, frequent data from current or past research trials, current numbers of important insects caught in pheromone traps, insect identification aids, and much more.
Anyone can request to receive the newsletter by emailing Jeremy Greene at greene4@clemson.edu to request inclusion. Please include your role (producer, consultant, industry rep, etc.) in South Carolina or elsewhere to ensure you are added in the correct email category.
Clemson Cooperative Extension is hosting two Corn and Soybean field days in July! The events will start at 8:30am and end around 12:00pm.
After presentations, free lunch will be served! The events are free, and topics will include key information on corn and soybean production and management practices. See the flier below.
Turf pests often go unnoticed until they cause significant economic and aesthetic damage. Last week, Dr. Zee Ahmed, assistant professor of turf and ornamental entomology, visited a homeowner who had invested over $25,000 in new St. Augustine grass—only to see it severely affected by southern chinch bugs. Whether introduced with the sod or migrating from neighboring lawns, these pests can wreak havoc in no time. With peak chinch bug activity approaching, early detection and management are crucial. To help identify, monitor, and control this destructive turf pest, Dr. Ahmed’s team put together a comprehensive field guide. Stay ahead of the damage—knowledge is your best defense!
Spodoptera frugiperda or fall armyworm is a common pest of numerous crops in South Carolina. Overwintering sites in North America include south Florida, Texas, Mexico, and the Caribbean. Each year, the insect migrates through much of the U.S., including South Carolina where infestations are generally found starting in June, with populations often increasing later in the season. We were surprised to find last week whorl infestations of fall armyworm so early in the growing season. The female moths lay eggs in masses on corn leaves, and larvae feed on leaves, creating rows of holes. This type of injury occasionally leads to yield losses when population densities are high in a field. Fall armyworm larvae has an inverted Y mark on its head (Figure 1) the distinguish it from related species. More information on the identification and management of fall armyworm can be found in our Land-Grant Press article.
Figure 1: Inverted Y mark on Spodoptera frugiperda larvae. Image credit: Steve L. Brown, University of Georgia, Bugwood.org.
Larvae of fall armyworm were found in our corn field trial located in Blacksville, South Carolina, last Thursday (May 8, 2025). Larvae were feeding on non Bt corn leaves when plants were at the V3 growth stage (Figure 2), with a typical aggregated pattern of several plants in a row infested, followed by uninfested plants. The trial has plots with Bt corn which were not infested with fall armyworm.
Figure 2: Fall-armyworm larvae feeding on corn leaf, Blacksville, SC. Image credit: Author.
It’s the time of year to be on the lookout for stink bugs in corn in South Carolina. Several species can cause damage, with the brown stink bug, Euschistus servus, and southern green stink bug, Nezara viridula, being the most common. While damage at the seedling stage can occur, the most common injury occurs when stink bugs feed from V14-VT. Which leads to crooked or banana shaped ears. We outline here information on stink bug biology, damage, and management.
Overview and identification
Stink bugs are shield-shaped insects, which have a similar appearance across species. As the name suggests, the brown stink bug is dark brown in color. There is a beneficial stink bug species called spined soldier bug that may be confused with brown stink bugs, but is distinguished by the presence of pointed and sharp shoulders (i.e. pronotum), which are absent on the brown stink bug. Immature or nymphal brown stink bugs are light green in color with a brown patch on their abdomen. Southern green stink bugs are slightly larger than brown stink bugs and green in color. The nymph of southern green stink bugs has a series of pink, white, and black spots on their abdomen, which can be used to distinguish them from other species. Other species such as the brown marmorated stink bug, green stink bug, and rice stink bug can be common in South Carolina, but are not common pests of corn.
Left: adult brown stink bug. Image credit: Gerald Holmes, Strawberry Center, Cal Poly San Luis Obispo, Bugwood.org. Right: fourth instar brown stink bug nymph. Image credit: Herb Pilcher, USDA Agricultural Research Service, Bugwood.org
Left: Adult southern green stink bug; note the presence of tachinid fly eggs. Right: fourth instar southern green stink bug nymph. Image credits: Russ Ottens, University of Georgia, Bugwood.org.
Damage to corn
Field corn is susceptible to injury during three key stages of field corn development: 1) emergence (VE) – six-leaf stage (V6), 2) two weeks prior to tasselling (VT) during the earliest stages of ear development, and 3) the first two reproductive stages of development (R1 and R2). During the early vegetative stages (i.e. VE-V6), stink bugs feed directly on the growth point of young plants, which can lead to stunted plants, tillers, leaf holes, deformities, or plant death in severe cases. Prior to tasseling, feeding leads to a characteristically crooked or “banana-shaped” ear, which limits overall yield potential and can expose the ear to secondary pests and pathogens. It is important to note that during these stages, the ear is not yet visible, but stink bugs can use their mouthparts to penetrate into the plant and find the developing ear to feed on. After pollination, feeding on kernels has limited potential to directly impact yield but can introduce grain quality issues in the form of fungi and mycotoxin contamination if bugs are at a high enough density.
Early vegetative injury from stink bug feeding, with severely stunted plants. Image credit: Tim Bryant, Clemson University.
Banana-shaped ears as a result of stink bug feeding during late vegetative stages prior to tasseling. Image credit: Tim Bryant, Clemson University.
Discolored kernels and fungal growth as a result of stink bug feeding during early reproductive stages of corn development. Image credit: Tim Bryant, Clemson University.
Sampling and management
During early vegetative stages, fields that are planted into heavy cover crop residue can potentially be at higher risk for large populations and injury. Proper seed slot closure can be affected by this heavy cover and expose more sensitive portions of the plant to feeding, increasing injury potential. Fields that were planted with soybeans in the previous season can also be at a higher risk for early-season infestations. As wheat matures and dries down, the interface of wheat and corn is at high risk for stink bug infestations. Wheat is an excellent early-season host for stink bugs, which can easily move into nearby corn during wheat harvest. Wheat harvest often coincides with the later vegetative stages of corn development, which are susceptible to stink bug injury.
For early vegetative infestations, insecticidal seed treatments, which are applied almost universally to commercial corn seed, can provide some protection from early season injury. Generally, fields with a history of stink bug pressure or at risk of injury from soil pests may benefit from increased seed treatment rates. Additionally, foliar insecticides can effectively manage stink bugs throughout the season, but it is critical to scout and only apply an insecticide at the economic threshold level for the given growth stage. The economic threshold is 1 bug per 10 plants from V1 to V6, 1 per 4 plants from V12-VT, and 1 per 2 plants at R1 and R2. The two most important considerations for applying an insecticide are achieving good coverage and timing the application properly. Ensuring canopy penetration is especially critical during the later stages of corn development. Bifenthrin is generally the most effective material to target brown stink bugs specifically. Applying an insecticide only at the economic threshold level will also preserve naturally occurring biological control agents in the field that broad-spectrum insecticides would otherwise kill.
For more detailed biology and management information on brown stink bugs in field corn, see this Land-Grant Press article and this scouting guide for stink bugs in southeastern corn.
