The European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a univoltine species that undergoes obligatory summer–winter diapause at pupal stage in the soil (2–5 cm) beneath host trees. To study the effects of photoperiod and relative humidity on diapause termination and post-winter developmental duration of R. cerasi, pupae collected from Dossenheim (Germany) were exposed to different photoperiod or relative humidity regimes during a chilling period ranging from 2 to 8.5 months. Specifically, pupae were exposed to four photoperiod regimes: (a) light conditions (24L:00D), (b) dark conditions (00L:24D), (c) short photoperiod (08L:16D) and (d) long photoperiod (16L:08D), as well as to three relative humidity regimes: (a) low (40% RH), (b) medium (60% RH) and (c) high (70–80% RH). Data revealed that relative humidity is not a significant predictor of diapause termination, but it affects the post-winter developmental period. Higher relative humidity promotes post-winter pupae development. On the other hand, photoperiod significantly affected both diapause termination and post-winter development of R. cerasi pupae. Light conditions (24L:00D) accelerate adult emergence, particularly for females. Regardless of the photoperiod (24L:00D, 00L:24D, 08L:16D), rates of adult emergence were high (>75%) for chilling intervals longer than 6.5 months. Nonetheless, exposure to a long day photoperiod (16L:08D), during chilling, dramatically reduced the proportion of adult emergence following 6 months exposure to chilling. Our findings broaden the understanding of factors regulating diapause responses in European cherry fruit fly, local adaptation and synchronization of adult emergence with the ripening period of major hosts.

中文翻译：

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光周期和相对湿度对Rhagoletis cerasi pupae滞育终止和越冬后发育的影响

欧洲樱桃果蝇，蜡菊（双翅目：Tephritidae）是一种单变种，在寄主树下的土壤（2-5 厘米）中的蛹期经历强制性的夏冬滞育。研究光周期和相对湿度对滞育终止和越冬后发育持续时间的影响。R. cerasi，从多森海姆（德国）收集的蛹在 2 至 8.5 个月的冷却期内暴露于不同的光周期或相对湿度条件下。具体来说，蛹暴露在四种光周期条件下：(a) 光照条件 (24L:00D)、(b) 黑暗条件 (00L:24D)、(c) 短光周期 (08L:16D) 和 (d) 长光周期 (16L :08D)，以及三种相对湿度状态：(a) 低 (40% RH)、(b) 中 (60% RH) 和 (c) 高 (70–80% RH)。数据显示，相对湿度不是滞育终止的重要预测因素，但它会影响冬季后的发育期。较高的相对湿度促进冬后蛹的发育。另一方面，光周期显着影响滞育终止和冬后发育。R. cerasi蛹。光照条件 (24L:00D) 加速了成虫的出现，特别是对于雌性。无论光周期如何（24L:00D、00L:24D、08L:16D），对于超过 6.5 个月的冷却间隔，成虫的出现率都很高（>75%）。尽管如此，在寒冷期间暴露于长日光周期（16L：08D），显着降低了暴露于寒冷6个月后成虫出现的比例。我们的研究结果拓宽了对欧洲樱桃果蝇滞育反应、成虫出现与主要寄主成熟期的局部适应和同步调节因素的理解。