Aleurocanthus spiniferus, an invasive pest native to Southeast Asia, exhibits rapid dispersal capacity and high eradication resistance. In recent years, there have been continuous records of its invasion into new host plants. Odorant-binding proteins (OBPs) are essential at the peripheral level of olfaction, and their olfactory function has been partially confirmed by research. This study explores the functions of key OBPs mediating host selection by measuring the in vivo and in vitro binding capabilities of OBPs from A. spiniferus to host volatiles. Under exposure to more than five host volatiles, the two OBPs, AspiOBP1 and AspiOBP2, exhibited significant differential transcriptional regulation. AspiOBP1 exhibited good binding affinity to (Z)-3-hexenol and 3-carene, and with binding energies greater than −3 kcal/mol, ARG-79 might be the critical amino acid site for AspiOBP1 binding to host volatiles. AspiOBP2 exhibited no binding to any of the six tested volatiles in fluorescent competitive binding assays. Adults fed with dsAspiOBP1 showed significantly reduced behavioral and EAG responses to the attractant 3-carene and two repellents [(Z)-3-hexenol and nonanal]. Adults fed with dsAspiOBP2 lost both behavioral and EAG responses to the attractant 3-carene and the repellent (Z)-3-hexenol. The findings of this study not only elucidate the binding mechanisms between OBPs of A. spiniferus and host volatiles but also provide new targets for the future development of novel plant-derived insecticides and RNA-based pesticides to control this pest.

Cold tolerance of natural enemy insects is a critical determinant of their overwintering survival and efficacy in biological control. The green lacewing (Chrysoperla nipponensis) is an important natural enemy insect that overwinters as adults in nature; however, its high overwintering mortality severely limits its effective application in spring. To investigate the molecular mechanisms underlying low-temperature adaptation, this study focuses on the temperature-sensitive Transient Receptor Potential (TRP) channels and their roles in the cold tolerance of C. nipponensis. The TRPA subfamily gene, Pyrexia-1, was identified and found to be significantly downregulated upon cold exposure. A functional analysis indicates RNAi-mediated knockdown of Pyrexia-1 significantly lowered both the supercooling point and the freezing point of C. nipponensis adults, enhancing their survival rate at −10 °C. These results indicate Pyrexia-1 as a negative regulator of cold tolerance. Further mechanistic investigation revealed that inhibition of Pyrexia-1 function specifically down regulates the expression of trehalase (TRE1) genes, resulting in a marked accumulation of the cryoprotectant trehalose in adults. This metabolic adjustment was accompanied by the upregulation of heat shock protein Hsp70. Overall, these findings establish Pyrexia-1 as a critical molecular switch linking temperature-sensing signals to the metabolic pathways governing freeze resistance, thereby orchestrating the systemic cold adaptation in C. nipponensis. This discovery provides novel insights into the molecular basis of insect low-temperature adaptation and suggests a potential strategy for enhancing the overwintering capacity of natural enemy insects by targeting this regulatory node.