Abstract: 【Aim】 Based on our previous studies of the effects of high temperature stress on the respiratorymetabolism of Calliptamus italicus, this study aims to determine the response of the discontinuous gas exchange cycle (DGC) duration in C. italicus to high temperature stress. 【Methods】 We examined the interburst duration, burst duration and DGC duration of C. italicus adults by using Sable Systems in the temperature range from 21 to 42℃ at 3℃ intervals. 【Results】 The interburst and burst durations decreased as the temperature went up. The interburst duration did not significantly change at temperatures lower than 33℃ (P＞0.05), whereas it rapidly shortened at temperatures over 33℃ and was significantly shorter at 39℃ than at other temperatures (P＜0.05). The burst duration was the longest at 21℃ and the shortest at 39℃ for females, whereas it was the longest at 24℃ and the shortest at 39℃ for males. The DGC duration decreased and the DGC frequency increased as the temperature went up. The interburst durations from 21 to 33℃ were not significantly different (P>0.05) between females and males, decreasing by 0.174 and 0.121 min per 3℃, respectively. The DGC frequency changes for females and males were similar at temperatures lower than 33℃, increasing by 0.0022 Hz per 3℃.Interburst durations significantly decreased at temperatures over 33℃ for females and males by 2.197 and 2.189 min per 3℃, respectively, but the DGC frequency increased by 0.0120 and 0.0085 Hz per 3℃, respectively. The interburst duration was close to zero at 39℃, and the DGC breathing pattern completely disappeared at 42℃. 【Conclusion】 With temperature rising, both the O₂ uptake rate and CO₂ release rate increase in C. italicus, which is realized by decreasing the DGC duration and increasing the DGC frequency.  

Key words: Calliptamus italicus, discontinuous gas exchange cycle (DGC), interburst duration, DGC frequency, high temperature stress