Sulfakinin Signaling Regulates Feeding and Energy Homeostasis in Hyphantria cunea : A Viable Target for Oral RNAi-Based Pest Control

Hyphantria cunea is a globally important pest of agricultural and forest ecosystems, owing its invasiveness to starvation tolerance, high feeding activity, and rapid reproduction. Neuropeptide signaling systems play a central role in regulating these key physiological processes. This study characterized the Sulfakinin (SK)/Sulfakinin receptor (SKR) pathway in H. cuneaand evaluated its potential for pest management. SK and SKR expression was influenced by nutritional status. Silencing SK or SKR disrupted energy homeostasis, increased food consumption, depleted energy reserves, reduced stress tolerance, and severely impaired reproduction. Conversely, SK peptide injection suppressed feeding during the early treatment period and significantly limited larval weight gain at 48–72 h. Furthermore, oral delivery of bacterially produced dsRNA targeting SK or SKR induced RNAi responses, resulting in increased larval mortality and delayed development. Collectively, these findings highlight the SK/SKR signaling pathway as a promising molecular target for sustainable RNAi-based strategies to control H. cunea.