P-143 - Freezing as a Treatment to Control Plodia interpunctella (Lepidoptera: Pyralidae) in Jujube

The Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), is a cosmopolitan pest that infests a wide range of stored cereal products, dried vegetables, fruits, nuts, and processed foods. It is the most significant pest of stored products in America and a primary pest affecting dried jujube during storage. In recent years, P. interpunctella has become the most important pest of stored jujube in California, with severe infestations leading to 100% crop loss. This study evaluated freezing and freeze-thaw cycles as potential treatments to eliminate P. interpunctella in heavily infested dried jujube. After treatment, eggs and larval stages were dissected from jujube and assessed for mortality. In total, over 10,000 eggs and larvae were examined. Freezing at approximately −15°C (range: −12.5 to −16.5°C) for 96 hours resulted in 95% mortality of eggs and larvae. A freeze-thaw cycle—consisting of freezing at −15°C for 48 hours, thawing at 22°C for 48 hours, followed by freezing again at −15°C for 72 hours—achieved 100% mortality. These findings suggest that cold storage can be integrated into jujube storage protocols as a safe, non-chemical method for controlling P. interpunctella infestations.