Moraiti Cleopatra A, Köppler Kirsten, Vogt Heidrun, Papadopoulos Nikos T
Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Crop Production and Rural Environment, University of Thessaly, Fytokou ST., Volos, 384 46Magnesia, Greece.
Centre for Agricultural Technology Augustenberg (LTZ), Neßlerstr. 25, 76227Karlsruhe, Germany.
Bull Entomol Res. 2020 Oct;110(5):588-596. doi: 10.1017/S0007485320000073. Epub 2020 Mar 12.
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.
欧洲樱桃实蝇（Rhagoletis cerasi，双翅目：实蝇科）是一种一年一代的物种，在寄主树下土壤（2 - 5厘米）中的蛹期经历 obligatory 夏冬滞育。为了研究光周期和相对湿度对欧洲樱桃实蝇滞育终止和冬季后发育持续时间的影响，从德国多森海姆采集的蛹在2至8.5个月的低温期内暴露于不同的光周期或相对湿度条件下。具体而言，蛹被暴露于四种光周期条件：（a）光照条件（24小时光照：0小时黑暗），（b）黑暗条件（0小时光照：24小时黑暗），（c）短光周期（8小时光照：16小时黑暗）和（d）长光周期（16小时光照：8小时黑暗），以及三种相对湿度条件：（a）低（40%相对湿度），（b）中（60%相对湿度）和（c）高（70 - 80%相对湿度）。数据显示，相对湿度不是滞育终止的显著预测因子，但它会影响冬季后的发育时期。较高的相对湿度促进冬季后蛹的发育。另一方面，光周期显著影响欧洲樱桃实蝇蛹的滞育终止和冬季后发育。光照条件（24小时光照：0小时黑暗）加速成虫羽化，尤其是雌性。无论光周期如何（24小时光照：0小时黑暗、0小时光照：24小时黑暗、8小时光照：16小时黑暗），低温处理间隔超过6.5个月时成虫羽化率都很高（>75%）。然而，在低温处理期间暴露于长日照光周期（16小时光照：8小时黑暗），在6个月低温处理后显著降低了成虫羽化的比例。我们的研究结果拓宽了对调节欧洲樱桃实蝇滞育反应、局部适应以及成虫羽化与主要寄主成熟期同步化的因素的理解。
