Data from: Bottom-up effects of cruciferous cultivars on caterpillar parasitoid Diadegma insulare via its host Plutella xylostella
Data files
Oct 01, 2026 version files 81.27 KB
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Raw_data_3a0a15a3-2caf-4b9b-ae18-0c1bf422906d.xlsx
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README.md
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Abstract
The diamondback moth, Plutella xylostella (L.) (Plutellidae: Lepidoptera), is one of the major pests of cruciferous vegetables. To control this notorious pest, the caterpillar parasitoid Diadegma insulare (Cresson) (Ichneumonidae: Hymenoptera) is the most commonly used as a biocontrol agent. Efficient mass‑rearing of D. insulare is therefore essential to produce high‑quality parasitoids. In the present study, we examined the bottom-up indirect effects of ten cruciferous cultivars, mediated through P. xylostella, on the parasitism efficiency, developmental performance, and body fitness of D. insulare. The results revealed that White Marble (cauliflower) and Asha (cabbage), characterized by higher nitrogen and phosphorus levels and lower potassium levels than the other cultivars, had positive effects on the bioecological parameters and fitness of D. insulare. The durations of the egg-larval, pupal, and preadult stages of D. insulare were found to be optimal in association with these cultivars. Moreover, higher adult longevity, increased hind tibia length, and greater adult body weight of the parasitoid were also observed in relation to these two cultivars. These findings suggest that cruciferous cultivars with higher nitrogen and phosphorus and lower potassium content exert favorable effects on D. insulare through P. xylostella, and such cultivars may be strategically used to enhance parasitoid activity in the field, to optimise mass-rearing in the laboratory, and to support biological control programs in organic farming.
Dataset DOI: 10.5061/dryad.xwdbrv1th
Description of the data and file structure
Code/software
Any program that can open a spreadsheet, such as Microsoft Excel, is recommended.
File name: Raw_data_3a0a15a3-2caf-4b9b-ae18-0c1bf422906d.xlsx
In the sheet "Parasitism"
Columns "Cultivars" includes 10 cruciferous cultivars; columns "Replication" indicate replicate number, total 10 replicates; column "D. insulare Emerged" indicates number of Diadegma insulare parasite emerged; column "No Emergence - Mortality" indicates number of Plutella xylostella individuals which don't emerged and were not parasitized; column "Percent Mortality" is the percent of Plutella xylostella mortality; column "Corrected Mortality (Mc)" represents the percent of Plutella xylostella mortality corrected according to control; column "Parasitism" indicates percent of Plutella xylostella parasitized; column "Transformed" indicates that data of Plutella xylostella parasitized have been transformed by the arcsine square root; column "Back Transformed" indicates that transformed data of Plutella xylostella parasitized have been back transformed; column "Parasitism mean" indicates mean of back transformed parasitism for a given cultivar; column "S.E. indicates standard error of parasitism mean.
Some cells are highlighted in grey. The control experimental units were included to determine the natural mortality of P. xylostella larvae and did not receive any parasitoid release. Therefore, no D. insulare emerged from these experimental units, and the corresponding cells were left empty and highlighted in grey.
In the sheet "Sex ratio"
Columns "Cultivars" includes 10 cruciferous cultivars; column "Replication" indicates replicate number, total 10 replicates; column "D. insulare" indicates number of Diadegma insulare parasitoids emerged; column "Male" indicates number of males emerged; column "Female" indicates number of females emerged; column "Sex Ratio" indicates proportion of females versus males emerged; column "Female (%) indicates percent of females emerged; column "Transformed" indicates that data of D. insulare females percent emerged have been transformed by the arcsine square root; column "Back Transformed" indicates that transformed data of D. insulare females percent emerged have been back transformed; column "Sex Ratio*" indicates sex ratio of D. insulare females emerged obtained from Back Transformed percent; column "Total" indicates total number of parasitoids emerged from a given cultivar; column "Male" indicates number of males emerged from a given cultivar; column "Female" indicates number of females emerged from a given cultivar; column "Sex Ratio av" presents avarage number of sex ratio of females versus males on a given cultivar; "S.E. represents standard error of sex ratio of mean.
In the sheet "Biological parameters"
columns "Cruciferous Cultivars" include 10 cruciferous cultivars; column "Egg-Larvae Duration (Days)" indicates number of days D. insulare male parasitoid was in Egg-Larvae stages; column "Pupal Duration (Days)" indicates number of days D. insulare male parasitoid was in pupae stage; column "Pre-Adult Duration (Days)" indicates number of days D. insulare male parasitoid was a Pre-Adult; column "Adult Longevity (Days)" indicates number of days D. insulare male parasitoid lived as an adult; column "Hind Tibia Length (mm)" indicates length of D. insulare male parasitoid tibia in milimeters; column "Adult Body Weight (mg)" indicates body weight of D. insulare male parasitoid in miligrams;
column "Egg-Larvae Duration (Days)" indicates number of days D. insulare female parasitoid was in Egg-Larvae stages; column "Pupal Duration (Days)" indicates number of days D. insulare female parasitoid was in pupae stage; column "Pre-Adult Duration (Days)" indicates number of days D. insulare female parasitoid was a Pre-Adult; column "Adult Longevity (Days)" indicates number of days D. insulare female parasitoid lived as an adult; column "Hind Tibia Length (mm)" indicates length of D. insulare female parasitoid tibia in milimeters; column "Adult Body Weight (mg)" indicates body weight of D. insulare female parasitoid in miligrams; column "Egg-Larvae Duration (Days)" "male" indicates average length in days male parasitoid spent as Egg-Larvae when reared on the host associated with the given cruciferous cultivar; column "Egg-Larvae Duration (Days)" "S.E." indicates standard error of average length in days male parasitoid spent as egg and larvae when reared on the host associated with the given cruciferous cultivar; column "Egg-Larvae Duration (Days)" "female" indicates average length in days female parasitoid spent as Egg-Larvae when reared on the host associated with the given cruciferous cultivar; column "Egg-Larvae Duration (Days)" "S.E." indicates standard error of average length in days female parasitoid spent as Egg-Larva when reared on the host associated with the given cruciferous cultivar;
column "Pupal Duration (Days)" "male" indicates average length in days male parasitoid spent as pupae when reared on the host associated with the given cruciferous cultivar; column "Pupal Duration (Days)" "S.E." indicates standard error of average length in days male parasitoid spent as pupae when reared on the host associated with the given cruciferous cultivar; column "Pupal Duration (Days)" "female" indicates average length in days female parasitoid spent as pupae when reared on the host associated with the given cruciferous cultivar; column "Pupal Duration (Days)" "S.E." indicates standard error of average length in days female parasitoid spent as pupae when reared on the host associated with the given cruciferous;
column "Pupal Duration (Days)" "male" indicates average length in days male parasitoid spent as pupae when reared on the host associated with the given cruciferous cultivar; column "Pupal Duration (Days)" "S.E." indicates standard error of average length in days male parasitoid spent as pupae when reared on the host associated with the given cruciferous cultivar; column "Pupal Duration (Days)" "female" indicates average length in days female parasitoid spent as pupae when reared on the host associated with the given cruciferous cultivar; column "Pupal Duration (Days)" "S.E." indicates standard error of average length in days female parasitoid spent as pupae when reared on the host associated with the given cruciferous;
column "Adult Longevity (Days)" "male" indicates average length in days male parasitoid spent as adult when reared on the host associated with the given cruciferous cultivar; column "Adult Longevity (Days)" "S.E." indicates standard error of average length in days male parasitoid spent as adult when reared on the host associated with the given cruciferous cultivar; column "Adult Longevity (Days)" "female" indicates average length in days female parasitoid spent as adult when reared on the host associated with the given cruciferous cultivar; column "Adult Longevity (Days)" "S.E." indicates standard error of average length in days female parasitoid spent as adult when reared on the host associated with the given cruciferous;
column "Pre-Adult Longevity (Days)" "male" indicates average length in days male parasitoid spent as pre-adult when reared on the host associated with the given cruciferous cultivar; column "Pre-Adult Longevity (Days)" "S.E." indicates standard error of average length in days male parasitoid spent as pre-adult when reared on the host associated with the given cruciferous cultivar; column "Pre-Adult Longevity (Days)" "female" indicates average length in days female parasitoid spent as pre-adult when reared on the host associated with the given cruciferous cultivar; column "Pre-Adult Longevity (Days)" "S.E." indicates standard error of average length in days female parasitoid spent as pre-adult when reared on the host associated with the given cruciferous;
column "Hind Tibia Length (mm)" "male" indicates average length of male parasitoid tibia in millimetres when reared on the host associated with the given cruciferous cultivar; column "Hind Tibia Length (mm)" "S.E." indicates standard error of average length of male parasitoid tibia in millimetres when reared on the host associated with the given cruciferous cultivar; column "Hind Tibia Length (mm)" "female" indicates average length of female parasitoid tibia in millimetres when reared on the host associated with the given cruciferous cultivar; column "Hind Tibia Length (mm)" "S.E." indicates standard error of average length of female parasitoid tibia in millimetres when reared on the host associated with the given cruciferous cultivar;
column "Adult Body Weight (mg)" "male" indicates body weight of male parasitoid in milligrams when reared on the host associated with the given cruciferous cultivar; column "Adult Body Weight (mg)" "S.E." indicates standard error of average body weight of male parasitoid in milligrams when reared on the host associated with the given cruciferous cultivar; column "Adult Body Weight (mg)" "female" indicates average body weight of female parasitoid in milligrams when reared on the host associated with the given cruciferous cultivar; column "Adult Body Weight (mg)" "S.E." indicates standard error of average body weight of female parasitoid in milligrams when reared on the host associated with the given cruciferous cultivar.
The experimental studies were carried out in the biocontrol laboratory of the Entomology Department, Pir Mehr Ali Shah - Arid Agriculture University, Rawalpindi, and in the farmers' fields of Taxila (Punjab, Pakistan).
Maintenance of cultures
Plant culture of cabbage and cauliflower cultivars
Five cultivars of cauliflower (Brassica oleracea var. botrytis L.) (i.e., Smilla, White Marble, Cashmere, White Magic, and TSX-C22) and 5 cultivars of cabbage (Brassica oleracea var. capitata L.) (i.e., Quisor, Stonehead, Baseball, Asha and Delight Ball) were selected and grown from seeds in seedling trays in the glasshouse of the Entomology Department at Pir Mehr Ali Shah - Arid Agriculture University, Rawalpindi. Peltracom® growth media was utilised to grow the plants. After 5 weeks, plants were transplanted into plastic pots with a diameter of 7.5 cm until the hardening stage. At the age of 45-50 days, plants were utilised for P. xylostella and D. insulare rearing and further experimental studies (Qureshi et al. 2020).
Plutella xylostella culture
Larvae and pupae of P. xylostella were collected from cauliflower/cabbage fields in Taxila (Punjab, Pakistan). The collected larvae were released onto fresh, untreated potted cauliflower/cabbage plants and reared individually in cages under controlled conditions (25°C, 65±5% RH, 16 L:8 D). Plants were replaced (where needed) until the feeding larvae pupated, and then the developed pupae were transferred to glass vials for adult emergence. The field-collected pupae were also placed singly in glass vials with a honey solution (20%) soaked in cotton plugs for emerging adults. To obtain homogeneous moth progeny and acclimatise them to the host plant cultivars as well as to controlled abiotic conditions, separate plant cultivars were placed in separate rearing cages, and mated P. xylostella were allowed to lay eggs for 6 hours. Emerged larvae were fed on relevant plant cultivars, and developed pupae were collected in marked glass vials having 57mm length and 27.5mm diameter (Qureshi et al. 2020). Emerging moths were used for further rearing and research studies.
Diadegma insulare culture
Parasitized larvae and pupae of P. xylostella were collected from cauliflower/cabbage crops in Taxila (Punjab, Pakistan). The collected larvae were brought to the insect growth chamber (25°C, 65±5% RH, and 16 L) for 8 days, released on fresh, untreated potted cauliflower/cabbage plants, and placed in rearing cages, whereas the collected pupae were placed singly in glass vials. From this field collection, emerged adults of D. insulare were identified and released into rearing cages for mating, which were provided with honey solution (20%) soaked cotton swabs in Petri plates. To obtain parasitoid progeny of homogeneous age and acclimatised to the host plant cultivars as well as to controlled abiotic conditions, nine potted plants from each cultivar were placed in separate rearing jars along with ten third-instar larvae of P. xylostella on each plant. After that, ten pairs of mated D. insulare were released for parasitisation in each rearing cage for 24 hours. Plants were replaced (where needed) until the pupation of all the larvae, and then the developed parasitised pupae were harvested and kept in marked glass vials for adult emergence (Qureshi et al. 2020). Emerging parasitoids were used for further rearing and research studies.
Experimental layout
Thirty potted plants of each cabbage and cauliflower cultivar were used, with each plant placed individually in a separate cage. Of these thirty plants per cultivar, twenty were infested with newly moulted third-instar larvae of P. xylostella at a density of ten larvae per plant. Among the infested plants, ten received one pair of two-day-old mated D. insulare, which were released for 24 hours, while the remaining ten infested plants received only P. xylostella and served as the infested control. Insects were observed every 24 hours, and the number of surviving larvae was recorded until pupation. Afterwards, the pupae were harvested and kept in labelled glass vials provided with a honey solution (20%) soaked in cotton plugs for emerging adults. Experimental studies were performed by maintaining the controlled conditions of the rearing chamber at 25°C, 65±5% relative humidity, and a photoperiod of 16 L: 8 D (Sarfraz et al. 2009).
After adult emergence, parasitism (%) was recorded and corrected using control mortality. Male and female parasitoids were distinguished based on the presence or absence of an ovipositor, and the number of individuals of each sex was counted. In addition, biological data regarding egg-larval duration (days), pupal duration (days), preadult duration (days), male and female adult longevity (days), hind tibia length (mm), and adult parasitoid weight (mg) were observed. For that purpose, the day on which larvae were exposed to the parasitoid was considered the date of oviposition. However, the day on which a larva from a certain cultivar fully developed into a D. insulare's pupa was considered the date of pupation. Moreover, the adult emergence day for each pupa was recorded, and the longevity of each emerged parasitoid adult was also observed until mortality. Dead parasitoids were allowed to dry for seven days, after which their weights were recorded with an analytical balance (Germany, BL-210S). The hind tibia lengths of the parasitoids were measured with an ocular micrometre attached to a microscope (Labomed SMZ1600, Los Angeles, CA, USA).
Biochemical analysis
Data and methods of biochemical analyses of all the studied plant cultivars used to calculate correlations between plant nutrients and various parasitoid characteristics are already published (Qureshi et al., 2026).
Statistical analysis
Parasitism (%) of D. insulare was determined using the following equation (Sarfraz et al., 2009):
Parasitism (%) = {(PDi~~ ÷ Lt) × 100} +** MC
Where: PDi = Number of emerged parasitoids (D. insulare); Lt*~~* = Total larvae exposed;
MC = Corrected mortality
MC was obtained using the Schneider-Orelli equation (1947):
The sex ratio was determined using the following equation:
A completely randomized design was used, and analysis of variance was performed for the studied parameters. All the parasitism and offspring sex ratio data were subjected to arcsine transformation prior to ANOVA. Means of significant treatments were compared using Tukey's HSD test (α=0.05). Pearson correlation was used to determine the relationships between plant nutrients and various biological parameters of D. insulare. All the collected data were analysed using Statistix 8.1 software (McGraw-Hill 2008), and graphical representations were created in Microsoft Excel (2010). The effects of ten cruciferous cultivars, mediated through P. xylostella, on the parasitism efficiency, developmental performance, and body fitness of D. insulare