Category: Ornamental entomology

The two-spot cotton leafhopper is spreading fast across the Southeast, threatening hibiscus and other ornamentals with hopperburn damage.

At Clemson’s Pee Dee REC, Dr. Zee Ahmed, along with his graduate students Nisha Yadav and Peilin Tan and research specialist Shawn Chandler, tested six insecticides, providing growers with the first science-based guidance for managing this pest in hibiscus nursery production.

Key grower takeaways:

1. Scout regularly with a 10x–30x lens

2. Match treatments to insect life stages

3. Rotate insecticides by IRAC group

4. Integrate biological & cultural controls

Figure 1: Field guide to the TSCL showing approximate adult size, life cycle stages and timing, key identification feature of two dark wing spots, common feeding damage symptoms, host plant range, scouting methods, and cultural/chemical control options.

Figure 2: Scan the QR code to access the complete field guide for TSCL, along with additional field guides on ornamental pests.

Read More: https://news.clemson.edu/clemson-launches-first-chemical-trial-to-combat-invasive-leafhopper-in-ornamentals/”

In greenhouse, nursery, and ornamental crop production, anticipating pest threats is crucial to protecting plant health, maintaining market access, and ensuring operational efficiency. The 2026 Insecticide, Miticide & Fungicide (IMF) Guide provides an updated, science-based framework for pest management, including chemical class charts, resistance management strategies, and pest-specific recommendations. It reinforces Integrated Pest Management (IPM) principles, accurate identification, consistent monitoring, cultural and biological controls, and strategic chemical rotations to reduce resistance risk, preserve beneficial organisms, and maintain compliance with state and federal regulations.
A complete guide is available here: 2026 Insecticide, Miticide & Fungicide Guide.

This year, Dr. Zee Ahmed, Assistant Professor of Turf and Ornamental Entomology at Clemson University, took proactive pest management a step further with the release of a specialized field guide on Thrips parvispinus, a pest still under regulatory concern in the United States. Designed for growers, inspectors, and extension agents, the guide equips stakeholders with tools to detect infestations early, before they escalate into costly outbreaks. Early detection not only minimizes unnecessary insecticide applications but also slows the development of resistance and helps avoid potential trade or quarantine complications.

Together, the 2026 IMF Guide and Dr. Ahmed’s field guide form a powerful one-two punch: a comprehensive management framework paired with a targeted diagnostic tool. For stakeholders, this means better decision-making, reduced chemical dependency, and a stronger position in meeting both production and regulatory demands, assuring healthier crops, healthier markets, and a healthier future for the industry.

Figure 1. Field Guide for Thrips parvispinus (Ahmed, 2025): A visual diagnostic reference to aid in proactive detection in ornamental and edible crops.

The spotted lanternfly (SLF) has been established in 19 U.S. states since its first detection in Pennsylvania in 2014. It was confirmed in North Carolina in 2022, Tennessee in 2023, Georgia in 2024 and South Carolina in 2025. While other neighboring states in the southeastern U.S. don’t yet have confirmed established populations, the risk of establishment remains high.

Dr. Zee Ahmed (Clemson University) and his colleagues—Dr.   Shimat Joseph (University of Georgia), Dr. Midhula Gireesh (University of Tennessee), Karla Addesso (Tennessee State University) and Alejandro Del Pozo-Valdivia (Virginia Tech) developed a management calendar to support early detection and proactive control efforts for ornamental growers in the Southeastern U.S. This seasonal framework offers practical guidance to help growers address SLF concerns proactively from late summer 2025 through summer 2026.

Here is the link  Spotted Lanternfly Management Calendar for Ornamental Growers in the Southeastern U.S.

Dr. Zee Ahmed (Clemson University) and Dr. JC Chong (SePRO Corporation) have co-authored a new article in the July 2025 issue of GrowerTalks, offering practical strategies for managing scale insects in nurseries and landscapes.

Key highlights include:

• Identifying the most common scale insects
• Understanding why the crawler stage is the most vulnerable and effective target for control
• Monitoring crawler emergence using sticky bands
• Selecting insecticides that minimize impact on beneficial insects

With over 1,100 species in North America, scale insects are often difficult to detect and manage. This guide helps growers improve treatment timing and reduce long-term infestations.

Read the full article: “Target Scale Insect Crawlers to Prevent Sticky Situations” (https://www.growertalks.com/Article/?articleid=27527) in GrowerTalks, July 31, 2025.

Figure 1: Comparison of different types of scale insects

Figure 2: Top 35 scale insect species on ornamental plants: voltinism and approximate crawler emergence timing

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:

• Accurate species identification to tailor control strategies
• Timed applications based on pest life cycles
• Rotation of systemic and contact insecticides to prevent resistance
• Sanitation protocols, including bench-washing and debris removal
• Efficacy data to guide product selection and application timing

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 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:

• Yellowing and wilting of iris leaf blades (Figure 2)
• Short, whitish serpentine tunnels near the base of leaves (Figure 2)
• Iris plants failing to bloom

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.