[Dynamic changes of cold-resistant substances of overwintering Chilo suppressalis (Walker) larvae]

Aimed to understand the mechanisms of cold-resistance of overwintering Chilo suppressalis (Walker) larvae at physiological and biochemical levels, the supercooling point (SCP) and the contents of water, ash, elements, fat, fatty acid, glycrol, total sugar, and protein in the larvae samples collected at different time were determined. The results showed that the SCP and the contents of free water, dissociated fat, total sugar, and protein in the overwintering larvae decreased first and increased then, whereas the contents of bound water, ash, combined fat, K, Na, Mg, Fe, Ni and Cr, and glycerol decreased after an initial increase. The components of fatty acids in overwintering larvae had some changes, but the main components were still 9-hexadecenoic acid, 9-hexadecanoic acid, and 9-octadecenoic acid. The contents of 9-hexadecenoic acid and 9-hexadecanoic acid decreased first and increased then, while that of 9-octadecenoic acid was in adverse. The dynamic changes of the contents of test substances could reflect the cold-resistance of overwintering C. suppressalis larvae.