The incidence and severity of environmental stressors associated with global climate change are increasing and insects frequently face variability in temperature and moisture regimes at variable spatio‐temporal scales. Coincidental with this, is increased thermal and hydric stress on insects as warming increases vapour pressure deficit (VPD), the drying power of the air. While the effects of mean temperatures on fitness are widely documented, fluctuations in both temperature and relative humidity (RH) are largely unexplored. Here, we investigated the effects of dynamic temperature and RH fluctuations (around the mean [28°C; 65% RH]) on low and high thermal tolerance of laboratory‐reared adult invasive Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), measured as critical thermal minima (CTmin), critical thermal maxima (CTmax), chill coma recovery time (CCRT) and heat knockdown time (HKDT). Our results show that increased environmental amplitude significantly influenced low and high temperature responses and varied across traits tested. The highest amplitude (δ12°C; 28% RH) compromised CTmin, CCRT and HKDT traits while enhancing CTmax. Similarly, acclimation to δ3°C; 7% RH compromised both low (CTmin and CCRT) and high (CTmax and HKDT) fitness traits. Variations in fitness reported here indicate significant roles of combined thermal and moisture fluctuations on B. dorsalis fitness suggesting caveats that are worthy considering when predicting species responses to climate change. These results are significant for B. dorsalis population phenology, management, quantifying vulnerability to climate variability and may help modelling future biogeographical patterns.

中文翻译：

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波动的环境影响入侵昆虫物种 Bactrocera dorsalis（双翅目：实蝇科）的耐热性

与全球气候变化相关的环境压力因素的发生率和严重程度正在增加，昆虫经常面临不同时空尺度上温度和湿度状况的变化。与此同时发生的是，随着气候变暖，增加了空气的干燥能力，即蒸汽压不足 (VPD)，昆虫的热应力和氢应力也会增加。虽然平均温度对健康的影响已被广泛记录，但温度和相对湿度 (RH) 的波动在很大程度上尚未得到探索。在这里，我们研究了动态温度和 RH 波动（平均 [28°C；65% RH]）对实验室饲养的成年侵入性实蝇（Hendel）（双翅目：实蝇科）的低热耐受性和高热耐受性的影响，测量作为临界热最小值（CTmin），临界热最大值（CTmax），冷昏迷恢复时间 (CCRT) 和热击倒时间 (HKDT)。我们的结果表明，增加的环境幅度显着影响了低温和高温反应，并且在测试的性状之间变化。最高振幅（δ12°C；28% RH）损害了 CTmin、CCRT 和 HKDT 特性，同时增强了 CTmax。同样，适应δ3°C；7% RH 损害了低（CTmin 和 CCRT）和高（CTmax 和 HKDT）的健康特征。此处报告的适应度变化表明热湿波动对 B. dorsalis 适应度的重要作用表明在预测物种对气候变化的反应时值得考虑的警告。这些结果对于 B. dorsalis 种群物候学、管理、量化对气候变化的脆弱性具有重要意义，并且可能有助于对未来的生物地理模式进行建模。