The Common cutworm (CCW), Agrotis segetum, also known as the Turnip moth, is a small insect with a disproportionately large impact on agriculture. While populations are often scattered and unpredictable, sudden outbreaks can devastate maize seedlings by cutting stems, boring into young plants, and reducing stands before crops can properly establish. Therefore, effective pest management depends on early and reliable detection.
Historically, this has been challenging because there is no consistently effective attractant for CCW under South African field conditions. This leaves farmers without a reliable and efficient way to track population pressure and make informed decisions.
The purpose of the study
Recognising this gap, Taryn-Maie Kuhn, Field Researcher at Insect Science, conducted multi-season field trials to determine whether a pheromone-based monitoring solution could be optimised for practical, real-world use in South African maize. By mimicking the female moth’s sex pheromone, synthetic lures offer a species-specific and environmentally responsible method to monitor moth activity and support data-driven pest management.
Trials were carried out during the 2022/2023 and 2024/2025 maize seasons in North West and Limpopo provinces. Two lure loading concentrations (standard 1x and elevated 10x) and two trap types, namely Yellow Delta Traps (YDT) and Yellow Bucket Funnel Traps (YBFT), were tested. Captures were recorded weekly over a 12 to 14-week period.
Clear evidence of success and what it means for farmers
Across all trial sites, pheromone treatments captured substantially more moths than non-pheromone controls, confirming that the lure is not only functional, but a reliable and practical monitoring tool for CCW.
This marks a significant advancement: farmers now have access to a working lure that allows them to track CCW population levels, understand population pressure trends, and make timely, strategic decisions about when to implement pest control interventions. Rather than reacting to damage after it occurs, growers can now proactively monitor risk, improving crop protection precision and sustainability.
Key findings
Results across locations revealed valuable insights:
- Site 1 (North West): Over 1,800 moths were captured overall. Trap catches were comparable across pheromone loadings, with no meaningful performance advantage observed for higher concentrations.
- Site 2 (North West): Nearly 900 moths were captured. The 1x lure recorded the highest catch at this site, reinforcing the absence of a consistent benefit from increased pheromone loading.
- Site 3 (Limpopo): Overall moth pressure was low (184 moths captured), and no discernible differences were observed between the treatments.
A particularly important outcome was that increasing pheromone concentration from 1x to 10x did not significantly improve trap performance across sites. This indicates that standard loading is sufficient and that lower-dose lures, being more cost effective, are equally effective for growers.
In terms of hardware, Delta Traps and Bucket Funnel Traps captured equal numbers of moths, meaning that farmers have flexibility to select trap type based on cost, availability, and operational preference.
Confidence in recommendations
While higher replication would always enhance statistical robustness, the 13-week duration of the trial provides strong and meaningful data from which confident and practical recommendations can be made. The consistency of trends across locations further reinforces the reliability of the observations.
Conclusion
This research represents a step forward in CCW management. For the first time, a dependable pheromone lure (once registered) will be available to support real-time field monitoring of Agrotis segetum in South African maize. Farmers can now:
- Monitor pest presence and population levels with confidence
- Assess population pressure rather than guessing
- Make timely, informed decisions on when intervention is necessary
- Avoid unnecessary spraying and improve resource efficiency
By delivering a proven, economical lure solution and demonstrating flexibility in trap choice, Insect Science provides growers with a practical, accessible monitoring tool that strengthens integrated pest management (IPM) and supports more sustainable, resilient maize production.
