Data and code from: Seasonal temperature fluctuation enables persistence of a model multi-trophic system
Data files
Sep 18, 2026 version files 185.85 KB
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Code.txt
52.70 KB
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README.md
5.74 KB
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Seasonality.xlsx
127.41 KB
Abstract
Seasonal thermal fluctuation is a dominant environmental force in temperate ecosystems, yet its role in shaping community dynamics and persistence remains poorly understood. We addressed this question by tracking high-resolution seasonal dynamics of a model system composed of the host Drosophila fly and two parasitoid species attacking hosts at the larval and pupal stages, respectively. Both parasitoid species increased in abundance steadily during the spring. The pupal parasitoid declined in summer but resurged in autumn, whereas the larval parasitoid declined after a summer peak. The host population remained relatively stable after an initial spring increase. Modelling predicted that the system would collapse under a constant cool environment due to excessive parasitism on hosts, whereas pupal parasitoids would be excluded under constant warmth. These predictions were validated by controlled laboratory mesocosm experiments. Life history assays clearly revealed that cool and warm seasons favor different parasitoid species: cooler temperatures resulted in higher mortality of immature larval parasitoids due to host immunity, whereas warmer temperatures narrowed the host exposure window and increased mortality of immature pupal parasitoids. These results demonstrate that seasonal temperature fluctuation maintains a fragile multi-trophic motif by preventing resource overexploitation and competitive exclusion, highlighting that intra-annual periodic forcing sustains biodiversity.
Please contact the corresponding author, XinQiang Xi (xixq@nju.edu.cn), for questions.
1. Seasonality.xlsx contains the following data sheets:
1.1 Figure 2, S3: Population dynamics data in the field mesocosm experiment
· Replicate: ID of mesocosm cages
· Date: the start time of counting for each batch of tubes
· AlParasitizedPupa: Number of parasitized pupae by larval parasitoid
· AlAdult: Number of emerged larval parasitoids
· AlEmergenceRate: Survival rate of larval parasitoid (AlAdult/AlParasitizedPupa)
· TdParasitizedPupa: Number of parasitized pupa by pupal parasitoid
· TdAdult: Number of emerged pupal parasitoids
· TdEmergenceRate: Survival rate of pupal parasitoid (TdAdult/TdParasitizedPupa)
· FlyPupae: Total number of hosts
· TotalParaRate: Parasitism rates of hosts by larval and pupal parasitoids
· FlyAdult: Survival host (FlyPupae-AlParasitizedPupa-TdParasitizedPupa)
1.2 Figure 3 AB: Larval & pupal development time under different temperatures
· Temperature: Temperature conditions for larval & pupal development. Unit= ℃
· Development time. Unit = hour
· Type: different developmental stages: larvae & pupae
1.3 Figure 3 C: Host immune efficacy against larval parasitoids under different temperatures
· Temperature: Temperature conditions. Unit= ℃
· NumPara: Number of larvae parasitized by larval parasitoid
· NumImm: Number of immature larval parasitoids killed by host immunity
1.4 Figure 5, S8): Population dynamics data in the lab mesocosm experiment
· ReplicateIDId of mesocosm cages
· Treat Temperaturere: Experimental temperature regimes
· Date: the start time of counting for each batch of tubes
· AlParasitizedPupa: Number of parasitized pupae by larval parasitoid
· AlAdult: Number of emerged larval parasitoids
· AlEmergenceRate: Survival rate of larval parasitoid (AlAdult/AlParasitizedPupa)
· TdParasitizedPupa: Number of parasitized pupa by pupal parasitoid
· TdAdult: Number of emerged pupaparasitoids
· TdEmergenceRate: Survival rate of pupal parasitoid (TdAdult/TdParasitizedPupa)
· FlyPupae: Total number of hosts
· TotalParaRate: Parasitism rates of hosts by larval and pupal parasitoids
· FlyAdult: Survival host (FlyPupae-AlParasitizedPupa-TdParasitizedPupa)
1.5 Figure S2: Population dynamics data in field survey
· Date: Sampling time
· Pupae: Total pupae collected
· Adult_Td: Abundance of adult pupal parasitoids in traps
· Adult_Al: Abundance of adult larval parasitoids in traps
· Emerge_Td: Number of emerged pupal parasitoids from collected Drosophila pupae
· Emerge_Al: Number of emerged larval parasitoids from collected Drosophila pupae
· CompleteEncapsule: Number of immature larval parasitoids killed by Drosophila larvae
· Mortality_Td: Number of immature pupal parasitoids that died from natural causes
· Mortality_Al: Number of immature larval parasitoids that died from natural causes
· TdPara: Parasitism rate of collected pupae by pupal parasitoids "(Emerge_Td+Mortality_Td)/Pupae"
· AlPara: Parasitism rate of collected pupae by larval parasitoids "(Emerge_Al+Mortality_Al+CompleteEncapsule)/Pupae"
· IM: Mortality rate of immature larval parasitoids caused by host larvae
1.6 (Figure S1): Population dynamics data in field survey
Date: Exact date
Mean temperature: idegreesee C
1.7 Figure S4A: Host immune efficacy against larval parasitoids across months
· Date: Month
· Numpara: Number of larvae parasitized by larval parasitoid
· NumImm: Number of immature parasitoids killed by host immunity
1.8 Figure S4B-D: Development time of studied insects across months
· Date: Month
· Species: Insect species
· DevelopmentalDays: Life cycle duration. Unit =t= Day
1.9 Figure S5 A-C: Fecundity of studied insects under different temperatures
· Temperature: Temperature conditions. Unit= ℃
· Species: Insect species
· Fecundity: Total egg production of hosts and parasitoids, respectively
1.10 Figure S5 D-F: Daily egg production of the two parasitoid species from emergence
· Day: Days since adult emergence
· Temperature: Temperature conditions. Unit= ℃
· Species: parasitoid species
· NumPara: Number of eggs laid
1.11 Model parameter_Table S1:
· λ, intrinsic growth rate of host fly
· α, attack rate of larval parasitoids on host fly
· β, attack rate of pupal parasitoids on host fly
· SA, survival rate of immature larval parasitoids
· ST, survival rate of immature pupal parasitoids
# 2. Code.txt: The provided R code file can directly read the xlsx file "Seasonality.xlsx". This R script reproduces all the figures and statistical analyses from what appears to be a study on seasonal population dynamics between a Drosophila host and its two parasitoid wasps (larval and pupal).