Abstract: 【Aim】 To explore the effects of low-temperature storage for varying duration on the survival, growth and development of Spodoptera litura pupae, and investigate the changes in metabolites of S. liturapupae subjected to low-temperature treatment over different time periods. 【Methods】The pupae of S. litura were subjected to treatment at 10 ℃ for varying duration (5, 10, 15, 20 and 25 d), and their developmental duration, emergence rates of female and male adults, next generation hatching rate and number of eggs laid per female were measured using conventional feeding methods. Targeted metabolomics was employed to analyze the changes in metabolites within the pupae at different treatment time. 【Results】The duration of S. litura pupae stored at 10 ℃ for varying duration was extended. The emergence rates of both female and male adults gradually decreased with extended cold storage time, while the oviposition period was reduced from 5.80 to 2.76 d. Additionally, the longevity of female and male adults was gradually shortened and the hatching rate of the offspring was gradually declined, and the number of eggs laid per female diminished gradually from 750.00 to 133.00 grains. Metabolomic analysis of S. litura pupae identified a total of 872 metabolites. In the comparison group with longer cold storage duration (processing for 20 d vs processing for 25 d), the differential metabolites were primarily classified into lipids and amino acids, along with their derivatives, with most metabolites enriched in the metabolic pathways of tyrosine, tryptophan and phenylalanine. In the comparison group with shorter cold storage duration (processing for 5 d vs processing for 10 d), the differential metabolites spanned a wider range of categories, with significant enrichment in the metabolic pathways of tryptophan, tyrosine and 2-oxocarboxylic acid. Among the pathways with the highest enrichment by metabolites in the comparison between the control group at room temperature and the treatment group under 10 ℃ for 25 d, only sorbitol, glutathione and taurine were highly expressed in the treatment group under 10 ℃ for 25 d. 【Conclusion】Among the tested storage duration (5－25 d), the optimal storage duration for S. litura pupae at 10 ℃ ranges from 15 to 20 d. This storage condition minimally impacts their development, and the metabolites produced under this treatment are diverse. The enriched metabolites are predominantly concentrated in various amino acid metabolic pathways. These findings provide valuable insights into the cold resistance mechanisms of S. litura pupae at low temperatures.

Key words: Spodoptera litura, pupal stage, cold storage treatment, growth and development, targeted metabolomics, metabolic differences