Data to: Single and combined effects of Drosophila suzukii and D. melanogaster on sour rot development in viticulture

Sour rot is a disease complex that causes serious damage in viticulture. The common vinegar fly Drosophila melanogaster (Diptera: Drosophilidae) is associated with sour rot in overripe or otherwise damaged grapes. Drosophila suzukii (Diptera: Drosophilidae) is an invasive species, which is suspected to induce sour rot in previously undamaged grapes due to the flies’ ability to infest healthy, undamaged soft fruits with its serrated ovipositor. As a consequence, infection of healthy grapes by D. suzukii may facilitate the colonization by D. melanogaster.
The aim of this study was to investigate the single and combined influence of D. suzukii and D. melanogaster on sour rot development under near-natural conditions in the vineyard, along with laboratory experiments under controlled climate. For that, manipulative experiments with gauze-bagged grapes comprising four different treatments: 1) D. suzukii, 2) D. melanogaster, 3) both Drosophila species combined and 4) without flies as control were performed in 2017 and 2018. Subsequently, sour rot development was determined by measuring the volatile acidity levels.
All experiments were performed around the harvest, started with the adding of the flies and ended with the determination of the volatile acid levels (as an indicator for sour rot). Field experiments were set up in a randomized block design: Blocks comprised four different treatments and were repeated 10 times and randomly distributed over the vineyard. For the laboratory experiments, the same experimental set up was chosen with four treatments repeated 10 times and randomly distributed in the climatic chamber. Therefore, one grape cluster per sample was placed in a plastic box. For all experiments n = 40 samples (4 treatments x 10 replicates) were used to check for differences in volatile acidity levels between the treatments performing variance analyses followed by post hoc tests.
The raw data supporting the results in the paper are presented in three datasets referring to the five figures in the publication. A legend, explaining the different variables used in the datasets is given in a separate document.
Dataset 1 is from the semi-field experiments in 2017 and underlies figure 1, 2 and 3 and related analyses. In two experimental repetitions starting at 30.8.2017 and 6.9.2017 and ending three weeks later at 20.9.2017 and 25.9.2017, grapes were exposed to the four different treatments in gauze sleeves in the field, followed by an incubation in the laboratory. In this experiment, additionally to the volatile acidity of the grape clusters, the fly emergence rates and grape cluster weight were determined.
Dataset 2 is from the field experiments in 2018 and underlies figure 4 and related analyses. The experimental setup was same as in dataset 1, but the experiment took place completely in the vineyard. Again, two experimental repetitions were performed starting at 24.8.2018 and 31.8.2018 and ending with the determination of volatile acidity at 13.9.2018 and 20.9.2018.
Dataset 3 is from the laboratory experiments in 2018 and underlies figure 5 and related analyses. For that, two laboratory repetitions were performed starting at 29.8.2018 and 4.9.2018 by placing one grape cluster per sample in a plastic box. The experimental setup was the same as in the field experiments with four treatments repeated 10 times and distributed randomly in the climatic chamber. The experiment ended after two weeks with the determination of volatile acidity of the grape cluster at 12.9.2018 and 29.9.2018 respectively.

酸腐病（Sour rot）是一类对葡萄栽培造成严重危害的复合病害。常见的醋蝇——黑腹果蝇（Drosophila melanogaster，双翅目：果蝇科），与过熟或受损葡萄上的酸腐病存在关联。斑翅果蝇（Drosophila suzukii，双翅目：果蝇科）是一种入侵物种，因其拥有锯齿状产卵器，可侵染健康、未受损伤的柔软果实，因此被推测可在原本未受损伤的葡萄上诱发酸腐病。由此，斑翅果蝇对健康葡萄的侵染可能会为黑腹果蝇的定殖提供便利。
本研究旨在探究斑翅果蝇与黑腹果蝇单独及联合作用下，葡萄园近自然条件与可控气候实验室条件中酸腐病的发生发展情况。为此，研究团队于2017年与2018年开展了套纱网袋葡萄的控制性实验，共设置4组处理：1）斑翅果蝇组；2）黑腹果蝇组；3）两种果蝇联合组；4）无果蝇对照组。后续通过测定挥发性酸度水平，以评估酸腐病的发展程度。
所有实验均围绕收获期开展，以投放果蝇为起始节点，以挥发性酸度（酸腐病的指示指标）的测定为结束节点。田间实验采用随机区组设计：每个区组包含4组处理，重复10次，并随机分布于整个葡萄园。实验室实验采用相同的实验设置，同样设置4组处理并重复10次，随机放置于人工气候箱内。实验中每份样本采用1串葡萄，置于塑料盒中。所有实验共设置n=40个样本（4组处理×10次重复），通过方差分析及事后检验，探究不同处理间挥发性酸度水平的差异。
支撑本论文研究结果的原始数据分为3个数据集，对应论文中的5幅图表。另有一份独立文档对数据集所使用的各类变量进行了解释说明。
数据集1来源于2017年的半田间实验，对应图1、图2、图3及相关分析。实验包含2次重复，分别于2017年8月30日与2017年9月6日启动，3周后于2017年9月20日与2017年9月25日结束。实验中，葡萄以纱网套袋的方式置于田间，接受4组不同处理，随后移至实验室进行孵育。除测定葡萄串的挥发性酸度外，本实验还同时统计了果蝇羽化率与葡萄串重量。
数据集2来源于2018年的田间实验，对应图4及相关分析。实验设置与数据集1一致，但全程均在葡萄园内开展。同样包含2次实验重复，启动时间为2018年8月24日与2018年8月31日，以2018年9月13日与2018年9月20日的挥发性酸度测定为结束节点。
数据集3来源于2018年的实验室实验，对应图5及相关分析。实验包含2次重复，于2018年8月29日与2018年9月4日启动，每份样本的1串葡萄置于塑料盒中。实验设置与田间实验一致，设置4组处理并重复10次，随机放置于人工气候箱内。实验于2周后结束，分别于2018年9月12日与2018年9月29日完成葡萄串的挥发性酸度测定。