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

 Abstract : 
 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 .