TRPA1-kinase axis polarization: Nepetalactone drives pest repulsion and predator attraction via divergent PKC/CaMKII signaling.

INTRODUCTION: Nepetalactone, an iridoid compound derived from Nepeta cataria, is a potent TRPA1 agonist known to repel hematophagous insects. However, its ecological roles and molecular mechanisms within agricultural ecosystems remain largely unexplored. OBJECTIVES: This study aimed to investigate: (1) the species-specific effects of nepetalactone on pests and predator insects, (2) its action on TRPA1 orthologs, and (3) its potential for push-pull pest control strategies. METHODS: We employed multi-tiered approaches including behavioral assays (two-choice tests, Y-tube olfactometry), molecular techniques (RNAi, qRT-PCR, FISH, Western blot), calcium imaging, and electrophysiology to assess behavioral responses and underlying mechanisms. Field trials further validated pest suppression efficacy. RESULTS: Nepetalactone exhibits dual functionality: it activates TRPA1 orthologs through conserved cysteine-rich domains, triggering calcium influx and aversion in three sap-sucking pests (Cacopsylla chinensis, Diaphorina citri, Megalurothrips usitatus; Order: Hemiptera). Conversely, it paradoxically attracts two predatory ladybeetles (Harmonia axyridis, Propylea japonica). Mechanistically, this behavioral dichotomy arises form divergent downstream kinase signaling - PKCα mediates repellency in pests, whereas CaMKII drives attraction in predators - despite conserved TRPA1 activation. Field trails validated operational synergy: nepetalactone combined with predatory ladybeetles achieving >90 % pest suppression through integrated push-pull effects. Our integrated approach (calcium imaging, RNAi, electrophysiology) reveals that TRPA1-kinase axis polarization governs species-specific chemoperception. CONCLUSION: These findings resolve the ecological paradox wherein a single semiochemical elicits opposing trophic behaviors. nepetalactone is established as a keystone agent for sustainable pest management, providing a molecular blueprint for engineering TRPA1-targeted repellents. Furthermore, it advances push-pull strategies by exploiting predator-pest signaling networks.