Enterobacter supplement and ambient conditions determine the performance of sterile male Mediterranean fruit flies
Data files
Jun 10, 2026 version files 53.06 KB
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Mating_Data.csv
49.71 KB
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README.md
3.35 KB
Abstract
Sterile Insect Technique (SIT) efficacy depends on field survival, dispersion capacity, and critically, mating competitiveness of the released sterile males. These parameters are influenced by mass-rearing, handling, sterilization, and environmental conditions. In true fruit flies (Diptera: Tephritidae), symbionts influence host physiology and behaviour; however, the potential of inactivated bacterial supplements to improve sterile male mating performance under field conditions remains insufficiently explored. We investigated whether partial replacement of dietary protein with inactivated Enterobacter sp. AA26 biomass during larval development improves mating performance of sterile Ceratitis capitata (Wiedemann) males, and whether performance varies with ambient conditions. VIENNA 8 Genetic Sexing Strain (GSS) males were reared on either an Enterobacter-enhanced or a non-enhanced larval diet (typical) and evaluated in field-cage mating competitiveness assays during summer, autumn and spring. Enterobacter-enhanced larval diet increased mating competitiveness, quantified by the Relative Sterility Index (RSI), across all seasons. Season significantly affected mating competitiveness, with males demonstrating higher RSI during spring and the lowest in summer under high ambient temperatures. Mating latency and duration were influenced by season but not by larval diet. Matings initiated sooner and lasted less during summer than during autumn or spring. No significant larval diet × season interaction was observed for mating competitiveness, latency or duration. Overall, larval supplementation with autoclaved Enterobacter biomass increased sterile male mating competitiveness under semi-field conditions, while seasonal ambient conditions remained a major driver of mating performance, indicating that combining nutritional interventions with seasonally optimized release strategies may maximize SIT efficacy.
Dataset DOI: 10.5061/dryad.70rxwdcd2
Description of the data and file structure
Data from: Enterobacter supplement and ambient conditions determine the performance of sterile male Mediterranean fruit flies
Scope: Investigate whether partial replacement of the protein source during larval development with autoclaved Enterobacter sp. AA26 biomass affects the mating performance of sterile C. capitata males under semi-field cage conditions.
Mating competitiveness under semi-field conditions:
Mating competitiveness assays were conducted in outdoor field cages (2 m height × 2.9 m diameter) containing potted citrus trees to promote natural mating behaviour (FAO/IAEA/USDA, 2019). Wild males were marked with water-based paint 24–48 h prior to trials for identification.
On each test day, 50 wild males (14–15 d old) and 50 sterile males (4–6 d old) were released into each cage and allowed 15–30 min to acclimate before introducing 50 wild females (14–15 d old). Mating pairs were recorded at 10–15 min intervals and collected individually to confirm successful copulation. Observations continued until approximately 15:00 (peak mating period).
Experiments were conducted in summer (July 2024), autumn (November 2024), and spring (May 2025), with six replicates per treatment per season.
Files and variables
File: Mating_Data.csv
Description:
Variables
- ID: Identification number of the mating pair
- Pair: Identification number of each mating pair per season
- Cage: number of field-cage in which the mating assay was conducted
- competition: type of medfly males that were competing for mating with the wild females
- Duration_(min): mating duration expressed in minutes
- Latency_(min): Mating latency was calculated as the time from female release in the field-cage until mating initiation of each pair
- mated_male: the type of male that succeeded to mate with the female
- Experiment_date: The exact date of the mating assay (DD/MM/YYYY)
- Season: The season during which the mating assay was conducted
Code/software
The dataset is provided in .csv format and can be opened using any spreadsheet software (e.g., Microsoft Excel, LibreOffice Calc) or statistical software capable of importing comma-separated values files.
All statistical analyses were performed using jamovi (version 2.3.28), an open-source graphical statistical software based on R. The analyses included calculation of mating competitiveness metrics (Relative Sterility Index, RSI), The effects of larval diet (typical vs Enterobacter-enhanced), season (summer, autumn, spring) and their interaction on RSI were assessed using analysis of variance (ANOVA). Data analysis of mating latency was performed using Generalized Linear Models (GLMs) for Gamma-distributed data (right-skewed distribution) with a log-link function. Data analysis of mating duration was performed using GLMs for normal distribution, with larval diet, season and their interaction as fixed factors.
jamovi can be freely downloaded from: https://www.jamovi.org
No proprietary software is required to view or analyze the raw data files.