Higher and more stable biological control of multiple herbivore species in diversified strip cropping systems
Data files
Apr 06, 2026 version files 357.65 KB
-
Eggs_data_2_years_JAE.csv
134.29 KB
-
Eggs_factorial_JAE.csv
24.18 KB
-
Pieris_data_2_years_JAE.csv
113.85 KB
-
Pieris_factorial_JAE.csv
15.31 KB
-
Plutella_data_2_years_JAE.csv
60.78 KB
-
README.md
9.24 KB
Abstract
Context: Agricultural intensification has simplified agroecosystems, reduced biodiversity and weakened natural pest control. Effective biological control requires reliable, long-term control of multiple herbivores. While studies investigated biological control in diversified cropping systems, there is little information to what extent pest suppression is sustained throughout the growing season and whether it provides satisfactory control of several herbivores.
Objectives: Here we assessed how increasing crop diversity and an “attract-and-reward” strategy influence effectiveness and temporal stability of biological control.
Methods: We compared predation, parasitism of eggs and caterpillars in a cabbage system with four levels of crop diversity: cabbage monoculture, cabbage-oat strip cropping, strip cropping with six crops, and an attract-and-reward system in which a strip cropping system was enhanced by inclusion of a parasitoid-attractive cabbage cultivar and nectar-providing buckwheat. Experiments were conducted at two organically-managed farms in the Netherlands in 2023 and 2024. Additionally, a full-factorial experiment was conducted in 2023 at one location to assess the effects of the attract-and-reward components. Temporal stability was quantified as the coefficient of variation and the proportion of sampling weeks in which each treatment exceeded the mean biological control level.
Results: Across locations and years, strip cropping enhanced parasitism rates of Pieris brassicae and Plutella xylostella compared with monocultures. Pieris brassicae parasitism increased from 28% in monocultures to 58% in strip cropping systems, while P. xylostella parasitism rose from 10% to 25–30%. Parasitism of M. brassicae eggs by Trichogramma spp. reached up to 30% in the strip cropping system with six crops, compared with 1% in monocultures. Attract-and-reward provided no improvement beyond standard strip cropping. Monocultures showed the highest coefficient of variation and exceeded the site-year mean in only 13% of weeks, compared to more than 60% in strip crop systems.
Synthesis & application: Our results highlight that strip cropping can enhance and stabilize biological control. Even simple two-crop designs provide clear benefits over monocultures, while increasing crop diversity to six crops offers additional advantages. Because the temporal stability of biological control increases with crop diversity, designing strip cropping systems with more crops can help maintain consistent and resilient pest regulation throughout the growing season.
Dataset DOI: 10.5061/dryad.4qrfj6qs4
Description of the data and file structure
The data were collected from field experiments designed to evaluate how strip cropping affects the effectiveness and temporal stability of biological pest control in cabbage systems. The study compared four cropping configurations: monoculture, simple strip cropping (cabbage–oat), diversified strip cropping with six crops, and an “attract-and-reward” system combining a parasitoid-attractive cabbage cultivar with buckwheat floral resources. Biological control metrics were assessed in two organically managed farms in the Netherlands during 2023 and 2024. Egg predation, eggs parasitism, and caterpillar parasitism were tested using sentinel eggs of Mamestra brassicae and a release-and-recapture method for Pieris brassicae and Plutella xylostella caterpillars. An additional factorial experiment was used to disentangle the effects of the attract (attractive cultivar) and reward (flowers) components.
Files and variables
File: Eggs_data_2_years_JAE.csv
Description: Results from the sentinel eggs of M. brassicae
Variables
- Year: Year in which the data was collected
- Location: Location in which the data was collected
- Round: Monitoring round in which the measurement was taken
- Date: Day of the year in which the measurement was taken
- Week: Calendar week of the year
- Treatment: Cropping system in which the biocontrol metrics were assessed: The Mono treatment represents a cabbage monoculture. The Strip treatment consists of strip cropping with cabbage and oat, while the Diversity treatment expands this system to include six crops: cabbage, oat, potato, pumpkin, faba bean, and a grass–clover mixture. The A&R (attract-and-reward) treatment is a modified version of the Strip system that incorporates the attractive cultivar Christmas Drumhead and buckwheat plants; in this treatment, measurements were taken on the Expect cultivar. The CD treatment refers specifically to measurements taken on the Christmas Drumhead cultivar within the attract-and-reward system.
- Field: Portion of field in which the replicates were arranged
- Strip: 3-meter-wide strip in which the selected plants were measured
- Plant: Plant in which the biocontrol metric was measured
- PlantID: Inique identifier for each plant
- Eggs: Number of eggs released on the specific plant in one round
- After.exp: Number of eggs remaining after being exposed to natural enemies in the field
- Predation: Number of predated eggs after being exposed to natural enemies in the field
- Pred.rate: Rate of eggs predated out of the total numer of eggs released (Pred.rate = Predation/Eggs)
- Parasitism: Number of parasitized eggs after being exposed to natural enemies in the field
- Para.rate: Rate of eggs parasitized out of the total numer of eggs recollected
(Para.rate = Parasitism/After.exp) - Biocontrol.rate: Rate of eggs parasitized or predated out of the total numer of eggs released
(Biocontrol.rate = (Predation+Parasitism) /Eggs)
All missing values under Para.ratein the dataset should be considered as not available. This indicates observations in which all eggs have been predatedwas therefore impossible to estimate the parasitism rate.
File: Plutella_data_2_years_JAE.csv
Description: Results from the release-and-recapture of P. xylostella caterpillars
Variables
- Year: Year in which the data was collected
- Location: Location in which the data was collected
- Round: Monitoring round in which the measurement was taken
- Date: Day of the year in which the measurement was taken
- Week: Calendar week of the year
- Treatment: Cropping system in which the biocontrol metrics were assessed as explained for Eggs_data_2_years_JAE.csv
- Field: Portion of field in which the replicates were arranged
- Strip: 3-meter-wide strip in which the selected plants were measured
- Plant: Plant in which the biocontrol metric was measured
- PlantID: Inique identifier for each plant
- Para: Number of parasitized caterpillars found on that plant in that round
- Unpara: Number of unparasitized caterpillars found on that plant in that round
- Rate: Parasitism rate as Para/Total
- Total: Total number of caterpillars found on that plant in that round
All missing values under Rate in the dataset should be considered as not available. This indicates observations in which no caterpillar was recollected and was therefore impossible to estimate the parasitism rate.
File: Pieris_data_2_years_JAE.csv
Description: Results from the release-and-recapture of P. brassicae caterpillars
Variables
- Year: Year in which the data was collected
- Location: Location in which the data was collected
- Round: Monitoring round in which the measurement was taken
- Date: Day of the year in which the measurement was taken
- Week: Calendar week of the year
- Treatment: Cropping system in which the biocontrol metrics were assessed as explained for Eggs_data_2_years_JAE.csv
- Field: Portion of field in which the replicates were arranged
- Strip: 3-meter-wide strip in which the selected plants were measured
- Plant: Plant in which the biocontrol metric was measured
- PlantID: Inique identifier for each plant
- Para: Number of parasitized caterpillars found on that plant in that round
- Unpara: Number of unparasitized caterpillars found on that plant in that round
- Rate: Parasitism rate as Para/total
- Total: Total number of caterpillars found on that plant in that round
All missing values under Rate in the dataset should be considered as not available. This indicates observations in which no caterpillar was recollected and was therefore impossible to estimate the parasitism rate.
File: Eggs_factorial_JAE.csv
Description: Results from the sentinel eggs of M. brassicae in the factorial experiment
Variables
-
Round: Monitoring round in which the measurement was taken
-
Date: Day of the year in which the measurement was taken
-
Treatment: Cropping system in which the biocontrol metrics were assessed.
Control: Basic Strip treatment with cabbage (var. Expect) and no addition of buckwheat or attractive cultivars.
Attract: Strip treatment with addition of Christmas Drumhead; measurements taken on the main variety Expect.
CD_Attract: Strip treatment with addition of Christmas Drumhead; measurements taken on the attractive variety Christmas Drumhead.
Reward: Strip treatment with addition of buckwheat.
A&R: Strip treatment with addition of Christmas Drumhead and buckwheat; measurements taken on the main variety Expect.
CD_A&R: Strip treatment with addition of Christmas Drumhead and buckwheat; measurements taken on the attractive variety Christmas Drumhead. -
Strip: 3-meter-wide strip in which the selected plants were measured
-
Plant: Plant in which the biocontrol metric was measured
-
Eggs: Number of eggs released on the specific plant in one round
-
After.exp: Number of eggs remaining after being exposed to natural enemies in the field
-
Predation: Number of predated eggs after being exposed to natural enemies in the field
-
Pred.rate: Rate of eggs predated out of the total numer of eggs released (Pred.rate = Predation/Eggs)
-
Parasitism: Number of parasitized eggs after being exposed to natural enemies in the field
-
Para.rate: Rate of eggs parasitized out of the total numer of eggs recollected
(Para.rate = Parasitism/After.exp) -
Biocontrol.rate: Rate of eggs parasitized or predated out of the total numer of eggs released
(Biocontrol.rate = (Predation+Parasitism) /Eggs)
File: Pieris_factorial_JAE.csv
Description: Results from the release-and-recapture of P. brassicae caterpillars in the factorial experiemnt
Variables
- Round: Monitoring round in which the measurement was taken
- Date: Day of the year in which the measurement was taken
- Treatment: Cropping system in which the biocontrol metrics were assessed as explained in Eggs_factorial_JAE.csv
- Strip: 3-meter-wide strip in which the selected plants were measured
- Plant: Plant in which the biocontrol metric was measured
- PlantID: Inique identifier for each plant
- Para: Number of parasitized caterpillars found on that plant in that round
- Unpara: Number of unparasitized caterpillars found on that plant in that round
- Para.rate: Parasitism rate as Para/Para+Unpara
- All missing values under Para.rate in the dataset should be considered as not available. This indicates observations in which no caterpillar was recollected and was therefore impossible to estimate the parasitism rate.
Code/software
The data are provided in Microsoft Excel format (.xlsx) Data analysis was conducted using R (version 4.4.3). The R scripts used for data processing and analysis will be made publicly available via Zenodo, enabling full reproducibility of the workflow.
Access information
Other publicly accessible locations of the data:
Data was derived from the following sources: