A subtropical insect species, Maruca vitrata, is invasive to temperate zones. Supercooling capacity of M. vitrata was confirmed in all developmental stages, in which egg exhibited the lowest supercooling point (SCP) at –22.5oC. However, low temperature lethality was observed at much higher temperatures than SCPs in all developmental stages. In addition, this nonfreezing injury increased with incubation time at rearing condition. Uncontrolled phenoloxidase activation appeared to cause the nonfreezing injury. Preexposure to a cool temperature before lethal low temperature significantly increased survival of M. vitrata. This cold hardening accompanied with increase of glycerol content in hemolymph. Transcriptome of M. vitrata under cond-hardening was assessed.