Dataset DOI: 10.5061/dryad.m0cfxppjs

Description of the data and file structure

Files and variables

Title: Fine-scale dietary differentiation among sympatric phytophagous  scarab beetles
Journal: Ecological Entomology
NCBI BioProject: PRJNA1457279 (raw Illumina sequences; public upon publication)

Data files

File: Olfactory_preference.xlsx

Description: Six-armed olfactometer bioassay results.

Variables

Rows: six treatment arms — Peanut, Soybean, Wheat, Corn, Potato, Control

Columns: twelve replicate groups (three replicates per species): Hp1–Hp3 Holotrichia parallela Ac1–Ac3 Anomala corpulenta Mt1–Mt3 Mimela testaceipes Pl1–Pl3 Polyphylla laticollis

Values: number of larvae (out of 20 per replicate, N = 60 per species) found in each chamber after 10 h. Analysed with one-way ANOVA and Tukey's HSD in GraphPad Prism 9.5.

File: Gut_content_OTU_table.xlsx

Description: Plant read counts from gut content DNA metabarcoding (trnL region, Illumina NovaSeq).

Variables

Rows: five host plant taxa (Peanut, Soybean, Wheat, Corn, Potato). Columns: same twelve replicate codes as above (Hp1–Hp3, Ac1–Ac3, Mt1–Mt3, Pl1–Pl3); each column represents one pooled gut sample (10 larvae per replicate, 3 replicates per species). Values: number of sequencing reads assigned to each plant taxon. Raw sequences: NCBI SRA, BioProject PRJNA1457279. Analysed with PERMANOVA_gut_content.R.

File: Adult_beetle_activity_trap_data.xlsx

Description: Daily light-trap catch counts for eight scarab beetle species from 7 June to 24 August 2025. The sheet contains the full daily time series used in analyses; additional sheets contain weekly summaries.

Variables

Columns: Date (format MMDD), then one column per species: Holotrichia diomphalia, Maladera orientalis, Holotrichia parallela, Metabolus tumidifrons, Anomala corpulenta, Maladera verticalis, Polyphylla laticollis, Mimela testaceipes.

Values: number of individuals captured per night.

Analysed with Scarab_beetle_circular_statistics_activity_overlap.R.

R Scripts

File: PERMANOVA_gut_content.R

Description: 

PERMANOVA on Bray-Curtis dissimilarity matrices computed from Gut_content_OTU_table.xlsx. Tests interspecific differences in gut content composition (vegan::adonis2, 9,999 permutations). Also computes pairwise Pianka's niche overlap index O and compares against a null distribution generated by the RA3 randomisation algorithm (1,000 iterations).

Required R package: vegan

File: Scarab_beetle_circular_statistics___activity_overlap_.R

Description: 

Circular statistical analysis of adult activity phenology using Adult_beetle_activity_trap_data.xlsx. Performs Rayleigh's test of uniformity and circular means of peak activity for each species, Watson's two-sample U2 tests for pairwise distributional comparisons, and coefficient of overlapping Delta with 95% percentile bootstrap confidence intervals (10,000 replicates; Dhat1 or Dhat4 estimator depending on sample size). Also produces Fig. 3 and Fig. S1.

Required R packages: circular, overlap, ggplot2, ggridges, dplyr, tidyr, patchwork, scales.

Code/software

PERMANOVA_gut_content.R Requires R package: vegan No other dependencies. Run directly in any R version ≥ 3.5.

Scarab_beetle_circular_statistics_activity_overlap.R Requires R packages: circular, overlap, ggplot2, ggridges, dplyr, tidyr, patchwork, scales Optional: ggbreak (for y-axis break in Fig. S1; if not installed, a plain linear y-axis is used automatically)

Install all required packages with: install.packages(c("circular", "overlap", "ggplot2", "ggridges", "dplyr", "tidyr", "patchwork", "scales", "ggbreak"))

Access information

Other publicly accessible locations of the data:

Raw Illumina sequencing data are deposited in NCBI SRA under BioProject accession PRJNA1457279, and will be publicly available upon publication.