Abstract: 【Aim】 To reveal the effects of autumn warming on cold tolerance of the peach fruit moth, Carposina sasakii Matsumura, a series of physiological parameters of larvae of the moth during diapause induction were investigated. 【Methods】 By using climatic chambers, the diapause of larvae of C. sasakii was induced under 9 alternating temperature regimes, i.e., 26-18, 26-20, 26-22, 28-18, 28-20, 28-22, 30-18, 30-20 and 30-22℃ (10 h high temperature, 14 h low temperature, RH 70%-80%, photoperiod 12L∶12D). The supercooling point (SCP), freezing point (FP), and the contents of water, fat and small molecular sugar alcohols in diapause larvae were investigated. 【Results】 The alternating temperature had no effect on diapause rates of larvaeunder suitable photoperiods, and all mature larvae from the fruit entered diapause. SCP and FP increased with daytime temperature increasing (SCP: F_{135, 2}=23.83, P<0.001; FP: F_{135, 2}=47.64, P<0.0001), and decreased significantly with the increase of nighttime temperature (SCP: F_{135, 2}=52.88,P<0.0001; FP: F_{135, 2}=33.34, P<0.0001). Water contents increased with nighttime and daytime temperature increasing (nighttime: F_135,2=13.47, P<0.0001; daytime: F_{135, 2}=10.39,P<0.0001), whereas the contents of fat decreased with nighttime increasing (F_{135, 2}=40.91, P<0.0001) and increased with the increase of daytime temperature (F_{135, 2}=161.18, P<0.0001). Contents of small molecular sugar alcohols varied with temperature (P<0.0001). The contents of trehalose, glucose and erythritol decreased with nighttime temperature increasing, but the contents of trehalose and erythritol increased with nighttime temperature increasing at daytime temperature 30℃, and the contents of glucose were not different. The glycerol contents increased with daytime temperature increasing and decreased with nighttime temperature increasing. The inositol and sorbitol contents were rotably different at different daytime or nighttime temperatures. 【Conclusion】 The SCP, FP, and the contents of water, fat and small molecular sugar alcohols in diapause larvae of C. sasakii are different at different diapause induction temperature. Diapause induction temperature plays an important role in diapause physiology of C. sasakii, and the initial physiological differences of diapause larvae may affect their overwintering.
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Key words: Carposina sasakii, diapause, diapause induction, thermoperiod, physiological indices, supercooling point (SCP), freezing point (FP）