Feeding on rapid cold hardening enhances cold tolerance of .

Low temperatures greatly influence newly introduced species, and increased cold tolerance can facilitate their establishment in new environments. The invasive alien species is distributed at high latitudes and altitudes, where it suffers more from cold stress than it would at low latitudes or altitudes. Whether cold stress influences the accumulation of cryoprotectants and cold tolerance in , and further influences the cold tolerance of its biological control agent, , through feeding remain unknown. We investigated the levels of cryoprotectants and metabolic changes in We found that the level of total sugar, trehalose, proline, and other cold responsible metabolites increased in after rapid cold-hardening (RCH) treatment, when compared to normal plants. These indicated that RCH treatment could improve the cold-hardiness of . We then investigated the levels of cryoprotectants and metabolic changes in . We found that fed on RCH-treated had higher levels of total sugar, trehalose, proline, glycerol, lipid, lower water content, lower super-cooling point, and increased cold tolerance compared to fed on normal . This suggested that fed on cold-hardened could increase its cold tolerance. Results showed a trophic transmission in insect cold tolerance. Our study enriches the theoretical basis for the co-evolution of cold tolerance in invasive and herbivorous insects.