By Blake Jackson
Crop specialists at the University of Kentucky are encouraging growers to use insecticides only when pest populations reach economically damaging levels.
According to Dr. Rogerio Lira, Dr. Felipe C. Batista, and Dr. Ric Bessin of the University of Kentucky, applying insecticides without proper scouting or adding them routinely to fungicide and herbicide applications can create significant long-term challenges for crop production.
While finding insects in a field may raise concerns, it does not automatically mean treatment is necessary. Many agricultural systems rely on beneficial insects, spiders, and naturally occurring pathogens that help keep pest populations under control.
When broad-spectrum insecticides are applied unnecessarily, these natural enemies can be eliminated, disrupting the balance of the field ecosystem.
Researchers pointed to recent examples in western Kentucky, where repeated pyrethroid applications targeting alfalfa weevil reduced beneficial insect populations.
As a result, aphid populations increased rapidly under favorable weather conditions, creating secondary pest problems that required additional treatments. In these situations, insecticide use contributed to new challenges rather than solving the original issue.
Another concern is the development of insecticide resistance. Repeated use of products with the same mode of action can allow resistant insects to survive and reproduce, gradually reducing the effectiveness of available control tools.
University researchers observed reduced susceptibility to several pyrethroid insecticides in fall armyworm populations during the 2024 and 2025 growing seasons.
When treatment is necessary, selecting products that are less harmful to beneficial insects can improve long-term pest management.
Extension specialists emphasize that regular field scouting, monitoring pest numbers, and comparing populations to established economic thresholds remain the most effective strategies for making sound insect management decisions.
By avoiding unnecessary applications, growers can protect beneficial organisms, slow resistance development, reduce input costs, and preserve insecticide effectiveness for future use.
Photo Credit: getty-images-kali9
Categories: Kentucky, Crops, Alfalfa