Gill’s mealybug has become an increasing concern for California pistachio growers, with the potential to impact both yield and crop quality if left unmanaged. Todd Burkdoll, Field Market Development Manager with Valent U.S.A., says early detection and proper timing are critical to keeping this pest under control.
Gill’s mealybug feeds on plant sap, diverting nutrients away from developing nuts and weakening the tree. In addition, the pest produces honeydew, which creates a sticky residue that can lead to sooty mold and blackened clusters. “It stains the hulls and creates a sticky mess,” Burkdoll said, noting that infestations can reduce market quality and overall productivity.
One of the biggest challenges with mealybugs is their behavior. They often hide under bark and only move into the canopy when conditions are favorable. Once populations establish and begin reproducing, control becomes more difficult. That’s why Burkdoll emphasizes treating early—when mealybugs begin moving onto new growth.
Senstar® Insecticide is one tool growers can use to effectively manage Gill’s mealybug. The product combines a systemic active ingredient with an insect growth regulator, allowing it to target pests in multiple ways. As insects feed, they ingest the systemic component, while the growth regulator disrupts development and prevents them from progressing through life stages.
The ideal application timing is shortly after pistachio bloom, when mealybugs are moving into the canopy and trees have sufficient leaf area for effective uptake. Burkdoll noted that with proper timing and good coverage, growers can often achieve strong control with a single application.
He also stressed the importance of thorough spray coverage, calling it one of the most common factors affecting performance. Slower application speeds and full canopy penetration can significantly improve results.
Scouting remains essential. By monitoring orchards and targeting known problem areas, growers can stay ahead of infestations and protect both yield and quality.
For more information, visit Valent.com/Senstar.
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