Integrated Pest Management

Month: September 2026

Ongoing research on defoliators, podworm, and natural enemies in South Carolina soybean fields

September 4, 2026

Entomologists at Clemson University have been sampling soybean fields across the state of South Carolina for soybean defoliators, podworms (Helicoverpa zea) and their natural enemies. Common soybean defoliators include the soybean looper, green cloverworm, velvetbean caterpillar, yellow stripped armyworm and the bean leaf beetle (Fig 1). The most predominant natural enemies include big-eyed bugs, assassin bugs, damsel bugs, spined soldier bug, and several lady beetle species. This research has several goals, including quantifying the spatial variability in insect densities and defoliation levels during full bloom and pod-filling stages, associating defoliation levels with defoliator species, and using landscape cropping area around soybean fields and field management information to predict insect densities and defoliations levels. Management of defoliators and podworms is primarily performed by chemical insecticide applications during pod set growth stage (R3). The ultimate goal of this project is to optimize insecticide usage by informing growers of the risk of infestations in their fields.

Fig 1:Green cloverworm, soybean looper and bean leaf beetle (from left to right), common soybean defoliators in SC.

Fig 2 (left): Soybean field defoliated in Marion County. Fig. 3 (right): pod worms present in the same field.

A total of 46 fields were sampled this year. Most fields did not reach the defoliation threshold, but some did for the corn earworm. In most cases, our visual estimates of defoliation levels in a field overestimated actual defoliation levels. This field in Marion County (Fig 2) was estimated to be around 10% defoliation when observing the canopy, and pod worms far exceeded the threshold number of 3 per 10 sweeps (Fig 3). However, when using software to accurately estimate defoliation based on photos of leaves, the field was at 3.4% defoliation only. None of the scouted fields have reached the defoliation threshold level for reproductive stages to date, but more fields remain to be scouted this year.

 

A Practical, Compatible Strategy for Greenhouse Mealybug Management

September 2, 2026

Contributing author: Dr. Zee Ahmed

Mealybugs remain one of the most persistent and costly pests in greenhouse ornamentals. Their waxy covering, protected feeding sites, cryptic diagnostics, and overlapping generations make them difficult to suppress with insecticides alone. Recent work from Clemson University provides growers with a clear, practical roadmap for integrating biological control with selective chemistries without undermining either tool.

This synthesis is based on two complementary publications:

Together, these pieces distill what growers can reliably use and how to deploy those tools in a compatible, stage‑aligned program.

 

Biological Control: What Actually Works in Greenhouses

Across commercial suppliers, only a small set of biological agents consistently perform against citrus, Madeira, long-tailed, and striped mealybugs:

  • Cryptolaemus montrouzieri (mealybug destroyer)
  • Chrysoperla spp. (lacewings)
  • Micromus variegatus
  • Parasitoids (Anagyrus pseudococci, Leptomastix dactylopii, Leptomastidea abnormis)
  • Entomopathogenic fungi (Beauveria bassiana, Isaria fumosorosea)

These are the tools growers can realistically access and integrate.

 

Chemical Tools: Selectivity Determines Compatibility

Many broad-spectrum insecticides (IRAC 1A, 1B, 3A, 4A) suppress mealybugs but also harm predators and parasitoids, even as dried residues. Clemson’s synthesis highlights selective chemistries that maintain compatibility:

  • Buprofezin (IRAC 16)
  • Pyriproxyfen (IRAC 7C)
  • Flonicamid (IRAC 29)
  • Afidopyropen (IRAC 9D)
  • Pyrifluquinazon (IRAC 9B)
  • Spirotetramat (IRAC 23)

These materials repeatedly show low direct toxicity to adult predators and minimal disruption when used thoughtfully.

Additional diagnostic and species‑specific guidance is available in Mondal et al. (2025), which outlines practical identification keys, IR‑4 efficacy patterns, and management considerations for citrus, Madeira, Mexican, Phormium, and root mealybugs.

 

Timing Is the Key to Compatibility

Growers often ask for a simple “safe vs. unsafe” list, but compatibility depends on when and how materials are used:

  • Apply selective insecticides early, before predator release.
  • Introduce Cryptolaemus or lacewings when populations are moderate, not explosive.
  • Use spot treatments to preserve predators.
  • Allow residues to decline before reintroducing biological control if a reset spray is necessary.

This timing‑based approach is the core of both GrowerTalks articles.

 

Operational Takeaways for Growers

  • Cryptolaemus remains the cornerstone predator for greenhouse mealybugs.
  • Lacewings provide supplemental pressure on crawlers.
  • Selective chemistries allow growers to intervene without disrupting biological control.
  • Integrated programs are most successful when pesticides and predators are used together, not in competition.
  • Compatibility is achieved through selectivity + timing, not by avoiding chemicals altogether.

 

References 

Ahmed, M.Z., Tan, P., & Mondal, P. 2027. Greenhouse Mealybug Management Guide for Growers. In: GrowerTalks 2027 Insecticide, Miticide & Fungicide Guide, pp. 7–8. Available at: https://www.growertalks.com/pdf/IMF2027_Guide.pdf

Mondal, P., Tan, P., & Ahmed, Z. 2025 Effective mealybug control strategies for greenhouse growers. In: Greenhouse Management 2025, August 8, 2025. Available at: https://www.greenhousemag.com/article/managing-mealybugs-pest-control-greenhouse/

Tan, P., & Ahmed, M.Z. 2026. A Practical, Compatible Strategy for Greenhouse Mealybug Management. GrowerTalks, August 31, 2026. Available at: https://www.growertalks.com/Article/?articleid=28194

 

Figure Caption: Mealybugs turning ornamentals into an all‑you‑can‑eat buffet. Compiled by Zee Ahmed (Clemson University).