Augmentative release of two Drosophila parasitoids did not suppress competitor populations in a vineyard
Data files
Oct 22, 2025 version files 42.67 KB
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Emergence_data.csv
6.49 KB
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Live_pupae_dissection_data.csv
1.23 KB
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README.md
6.27 KB
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Yellow_trap_data.xls
28.67 KB
Nov 06, 2025 version files 50.89 KB
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Emergence_data.csv
6.49 KB
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Live_pupae_dissection_data.csv
1.23 KB
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R_code.txt
7.84 KB
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README.md
6.65 KB
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Yellow_trap_data.xls
28.67 KB
Abstract
In this study, we released two widely used pupal parasitoids, Trichopria drosophilae Perkins (Hymenoptera: Diapriidae) and Pachycrepoideus vindemiae (Rondani) (Hymenoptera: Pteromalidae), into vineyards to test whether augmentative release of T. drosophilae or P. vindemiae suppresses the wild populations of the other species. We investigated whether the augmentative release of two pupal Drosophila parasitoid species (Trichopria drosophilae and Pachycrepoideus vindemiae) in the vineyard decreases the emergence rate of their competitors. Parasitoid emergence rate, parasitism rate, and host mortality were recorded.
Dataset DOI: 10.5061/dryad.rfj6q57n9
Description of the data and file structure
Parasitoid emergence rate, parasitism rate, and host mortality were recorded.
Files and variables
File: Emergence_data.csv
Description:
Variables
- CollectDate: Pupae collection time
- Plot: 3plots
- GrapeString: Two clusters of grapes as a unit
- Treat: Parasitoids release treatments and control groups, including Release Trichopria drosophilae, Release Pachycrepoideus vindemiae, and Control.
- Group: 3 different treatments, including a, b, d
- ReleaseT: Whether to release Td.: 1 for yes, 0 for no
- ReleaseP: Whether to release Pv.: 1 for yes, 0 for no
- PupaNumber: Number of pupae collected
- AlonePupaNumber: Selected pupae were individually placed in test tubes plugged with cotton, and counts were made after their emergence.
- AloneTEmergeN: Number of Td. emerged in test tubes
- ATEFemale: Number of female Td. emerged in test tubes
- ATEMale: Number of male Td. emerged in test tubes
- AlonePEmergeN: Number of Pv. emerged in test tubes
- APEFemale: Number of female Pv. emerged in test tubes
- APEMale: Number of male Pv. emerged in test tubes
- DroEmergeN: Number of Drosophila emerged
- TEmergeN: Number of Td. emerged (Excluding the pupae in test tubes and those dissected alive, count the number of Td. emerged from the remaining pupae)
- TEmergeFemaleN: Number of female Td. emerged (Excluding the pupae in test tubes and those dissected alive, count the number of female Td. emerged from the remaining pupae)
- TEmergeMaleN: Number of male Td. emerged (Excluding the pupae in test tubes and those dissected alive, count the number of male Td. emerged from the remaining pupae)
- PEmergeN: Number of Pv. emerged (Excluding the pupae in test tubes and those dissected alive, count the number of Pv. emerged from the remaining pupae)
- PEmergeFemaleN: Number of female Pv. emerged (Excluding the pupae in test tubes and those dissected alive, count the number of female Pv. emerged from the remaining pupae)
- PEmergeMaleN: Number of male Pv. emerged (Excluding the pupae in test tubes and those dissected alive, count the number of male Pv. emerged from the remaining pupae)
- FEmergeN: Number of a specific braconid species emerged
- FEmergeFemaleN: Number of female braconid emerged
- FEmergeMaleN: Number of male braconid emerged
- OtherEmergeN: Number of other parasitoids emerged
- DeadPupaN: Pupae that neither parasitoids nor Drosophila emerged
- DissectDeadPupaN: Number of dissected pupae from which from which neither parasitoids nor Drosophila emerged
- TNinDP: Number of Td. in dead pupae (neither parasitoids nor Drosophila emerged)
- PNinDP: Number of Pv. in dead pupae (neither parasitoids nor Drosophila emerged)
- FNinDP: Number of braconid in dead pupae (neither parasitoids nor Drosophila emerged)
- DissectLivePupaN: Number of live pupae dissected
- PupaNwithT: Number of live pupae dissected with Td. observed
- TNinLP: Total count of Td. observed in dissected live pupae
- PupaNwithP: Number of live pupae dissected with Pv. observed
- PNinLP: Total count of Pv. observed in dissected live pupae
- PEmergeRate: Total emergence rate of Pv.
- PNumber: Total number of Pv. emerged
- TEmergeRate: Total emergence rate of Td.
- TNumber: Total number of Td. emerged
- OtherEmergeRate: Emergence rate of other parasitoids
- TotalEmergeRate: Total emergence rate of two parasitoids (Td. and Pv.)
- DroUnknowDeathRate: Unknown reason mortality of Drosophila (neither parasitoids nor Drosophila emerged)
- DroDeathRate: Total mortality of Drosophila
- DroDeadPupaNumber: Total number of dead pupae
- DroUnknowDeadPupa: Number of unknown reason dead pupae (neither parasitoids nor Drosophila emerged)
File: Live_pupae_dissection_data.csv
Description:
Variables
- Date: Pupae collection time
- Grape: Grape varieties
- Treat: Parasitoids release treatments and control groups, including Release Trichopria drosophilae (Td), Release Pachycrepoideus vindemiae (Pv), and Control.
- Group: 3 different treatments, including a, b, d
- PupaNumber: Number of live pupae dissected
- PupaNumberWithT: Number of live pupae dissected with Td. observed
- TPRate: Total parasitism rate of Td.
- TNumber: Total count of Td. observed in dissected live pupae
- PupaNumberWithP: Number of live pupae dissected with Pv. observed
- PPRate: Total parasitism rate of Pv.
- PNumber: Total count of Pv. observed in dissected live pupae
- MultiParaPupa: Number of multiparasitism Pupae
- MPRate: Multiparasitism rate
- THyperParaPupa: Number of pupae hyperparasitized by Td.
- THPRate: Hyperparasitism rate of Td.
- PHyperParaPupa: Number of pupae hyperparasitized by Pv.
- PHPRate: Hyperparasitism rate of Pv.
- TotalPRate: Total parasitism rate of two parasitoids (Td. and Pv.)
File: Yellow_trap_data.xls
Description:
Variables
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Date: Deployment dates of traps
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Grape: Grape varieties
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Treat: Control plots
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DroNumber: Number of Drosophila
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TNumber: Number of Td. on traps
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TFemale: Number of female Td. on traps
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TMale: Number of male Td. on traps
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PNumber: Number of Pv. on traps
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PFemale: Number of female Pv. on traps
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PMale: Number of male Pv. on traps
File: R_code.txt
Description:
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This is the code I used for data visualization and analysis in R.ver. 4.2.3.
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The following packages may be required: “lme4”， “agricolae”， “nlme”， “ggplot2”，“multcomp”， “reshape2”， “fitdistrplus”， “lmerTest”， “dplyr”， “eoffice”， “tidyr”， “coin”.
Code/software
We tested whether the emergence and parasitism rate of two parasitoid species and the total mortality rate of Drosophila flies significantly varied among parasitoid releasing treatments using generalized linear mixed-effects models (GLMMs with binomial error structure). The investigation time nested within the grape variety was included as a random factor. Tukey’s HSD tests were conducted whenever a significant difference among treatments was detected. All the data analyses were conducted by R ver. 4.2.3 (R Core Team, 2020).
Access information
Other publicly accessible locations of the data:
- NA
Data was derived from the following sources:
- NA
The insects
The P. vindemiae and T. drosophilae populations were collected in a vineyard (36.66°N, 121.28°E) in Jinan, Shandong Province, China. They are reared in the lab by Shandong Academy of Agricultural Sciences using Drosophila melanogaster Meigen pupae. All populations were maintained in growth chambers at 25±0.5°C, 70%±0.5% relative humidity, and a photoperiod of 16:8 hours (Light: Dark).
Experimental design
Three trials with three different grape cultivars (Ruby Seedless, Concord, Kyoho) were conducted in a vineyard in 2022, where pesticide was prohibited. Our preliminary investigation before the experiment showed that P. vindemiae is the dominant parasitoid with over 20 times higher population density than T. drosophilae in the studied vineyards. For each trial, we established a control plot (without releasing parasitoids) plus two treatment plots: one releasing T. drosophilae and the other releasing P. vindemiae. Experimental plots were spaced 200 to 400 m apart, a distance sufficient to prevent cross-plot dispersal as the maximum foraging distance of the studied parasitoid species is less than 40 m in their life (Hougardy et al., 2022; Stacconi et al., 2018).
Newly mated female wasps were transferred from the insect rearing room into plastic vials (9.5 cm diameter × 10.3 cm height) using an aspirator. The lid of each vial was perforated with small holes to ensure ventilation. Each vial contained approximately 100 female wasps. A cotton ball soaked with a 50% honey solution was placed on top of each vial to feed the parasitoids. To sustain an effective population density when the host abundance was at its peak, we conducted six separate releases of parasitoids. Approximately 1,000 female wasps were released per plot in the augmentative release treatment groups on 28 July, 3, 9, 12, 17, and 24 August.
Pupae collection and dissection
Ten grape bunches were collected at each plot one week after every parasitoid augmentative release. Drosophila pupae on the grapes were transferred into plastic boxes that were covered by lids with approximately 1-mm-diameter holes for air exchange. A total of 5,467 pupae were collected across all plots. The number of emerged Drosophila flies and parasitoids from pupae collected in each plot was counted. Additionally, 288 live pupae were dissected before the emergence of Drosophila flies to assess parasitism by the two parasitoid species. At the end of the experiment, 1,865 dead pupae (from which neither parasitoids nor Drosophila flies emerged) were dissected to determine if they were parasitized. The emergence rate of parasitoids was quantified by the number of adult parasitoids that successfully emerged from collected pupae. The parasitism rate of parasitoids was quantified by dissecting live host pupae and recording observed stages of parasitoid offspring (eggs, larvae, or adults). Total mortality of Drosophila flies was determined by adding Parasitoid-emerged pupae (successful parasitism) and the dead pupae from which neither flies nor wasps emerged.
Field experiments inherently face uncontrolled factors such as weather variation, microhabitat heterogeneity, and the presence of other natural enemies. While we minimized pesticide disturbance and spatial interference by plot design, we could not fully account for all environmental variables. We do not release any parasitoids in the control plots; therefore, the control plots can be used to measure the natural parasitoid and host interaction strength.
Data analysis
We tested whether the emergence and parasitism rate of two parasitoid species and the total mortality rate of Drosophila flies significantly varied among parasitoid releasing treatments using generalized linear mixed-effects models (GLMMs with binomial error structure). The investigation time nested within the grape variety was included as a random factor. Tukey’s HSD tests were conducted whenever a significant difference among treatments was detected. All the data analyses were conducted by R ver. 4.2.3 (R Core Team, 2020).
Changes after Oct 22, 2025:
Added "R_code.txt" for data analysis.
All the data analyses were conducted by R ver. 4.2.3.
The following packages may be required: “lme4”， “agricolae”， “nlme”， “ggplot2”，“multcomp”， “reshape2”， “fitdistrplus”， “lmerTest”， “dplyr”， “eoffice”， “tidyr”， “coin”.