Battling a New Pest: Addressing the Threat of Carpophilus Truncatus in California’s Nut Industry
What We’ll Cover
The Challenge at Hand
Pecan weevils, codling moths, bacterial leaf scorch – these may be just a few of the threats facing tree nut growers in California and beyond, but they were joined this past year by a new name: Carpophilus truncatus.
Both the larvae and adult specimens of Carpophilus truncatus directly attack the kernel of affected nuts, which ultimately leads to reduced yield and quality. They have the ability to overwinter in unharvested mummy nuts – a factor that exacerbates the challenge of eradication.
While similar Carpophilus beetles have been reported as having infested walnuts in Argentina and Italy, Carpophilus truncatus in particular has been recognized as a top pest among almond producers in Australia for nearly a decade. The University of California Cooperative Extension’s Houston Wilson first detected the beetles in September of 2023, with infestations later confirmed across Stanislaus, Merced, Madera, and Kings counties. This widespread establishment and apparent presence for at least a year suggests that the impact may have been underestimated.
|Average amount of crop damaged when Carpophilus truncatus are present
- Scientific Reports, 2022
With the existing history of Carpophilus truncatus in Australia, there are a number of valuable insights and strategies for control that have proven effective:
Current methods involve direct inspection of hull-splits to check for signs of infestation.How to Reduce Risk
Instantly move from detection, to image evidence, to management alerts – improving response time.
Crop sanitation is a fundamental tool for managing Carpophilus, particularly the removal and destruction of unharvested mummy nuts to eliminate overwintering populations.
How to Reduce Risk
Automate SSOP task alerts for operators and overdue tracking for managers — preventing missed sanitation.
Industry researchers are actively working on additional guidance materials and surveying orchards to help establish California-specific identification, monitoring, and management strategies.
Taking the Initiative & Moving Forward
While the discovery of Carpophilus truncatus in California undoubtedly presents a challenge to the nut industry, collaborative research, vigilant monitoring, and proactive sanitation efforts by growers will have a significant impact on these invasive pests. With the experience garnered by years of handling the beetles in Australia, the California nut industry can adapt and thrive in the face of this emerging threat. Leveraging smart tools such as Provision can enable urgent action as spring approaches – and the window of opportunity to destroy overwintering beetles closes.