Dataset DOI: 10.5061/dryad.sf7m0cgkr

Description of the data and file structure

This README file is for all the data related to the research paper ‘Sexual selection in wild populations of seed bugs: the role of size in pre-copulatory mate choice by females and males’.

Authors: Ophelia S Fritsch and David M Shuker

In this study, we sampled mating and non-mating individuals of both Spilostethus pandurus and Lygaeus creticus in Sicily, directly in their habitat. We then measured them for three body size measurements and compared these between mated individuals and individuals found not mating to see patterns of non-random mating in regard to body size.

Throughout the R scripts and in document titles, the names ‘Spilo’ or ‘spilo’ are short for Spilostethus pandurus and ‘Creticus’ or ‘creticus’ are short for Lygaeus creticus.

Files and variables

Spreadsheets can be found in the folder 'Spreadsheets' under the zip file 'Spreadsheets.zip'.

Seven data spreadsheets are provided:

First, the spreadsheets titled ‘spilo.field.dataset.csv’ and ‘creticus.field.dataset.csv’ are the two raw datasets with the original variables, and are the ones used to do the analyses (see R scripts for each species).

Second, the ones titled ‘Spilostethus_pandurus_wild_caught_final_dataset.csv’ and ‘Lygaeus_creticus_wild_caught_final_dataset.csv’ are the final datasets, which include all new variables created during the analysis, including the principal component individual scores.

Thirdly, the spreadsheet titled 'Spilo_field_repeatability_measures.csv' is the dataset with the morphological measures from 32 individuals, which were re-measured to test the repeatability using the Intra Class Correlation Coefficients.

And finally, the two spreadsheets titled 'Spilo_photo_IDs_individual_IDs_and_measurements.csv' and 'Creticus_photo_IDs_individual_IDs_and_measurements.csv' contain data linking the raw photo IDs to the individual IDs and the dates the photos were taken.

Brief description of variables used in the seven spreadsheets:

date – date the individuals were measured

individual_ID – Individual identification, which was given pseudo-randomly

sex – individual sex

body_length – measure of body length in millimetres (mm)

thorax_width – measure of thorax width in millimetres (mm)

abdomen_width – measure of abdomen width in millimetres (mm)

pair_ID – pair identification for individuals that mated

status – status at the time of collection (collected mating or collected not mating)

collected_mating_Y_N – status at collection with Y (Yes) = 1 and N (No) = 0

body_length_sq – value of body length measure multiplied by itself (squared)

thorax_width_sq – value of thorax width measure multiplied by itself (squared)

abdomen_width_sq – value of abdomen width measure multiplied by itself (squared)

PC1_times_minus_1 – Individual scores for principal component 1, which had opposite signs

PC2 – individual scores for principal component 2

PC3 - individual scores for principal component 3

PC1 - individual scores for principal component 1 with the correct sign – used for analysis

PC_and_4 – individual scored for principal component 1 with the value 4 added

PC_and_4sq – the above multiplied by itself (squared)

vstd_body_length – variance standardised measure of body length (scaled)

vstd_thorax_width - variance standardised measure of thorax width (scaled)

vstd_adbomen_width - variance standardised measure of abdomen width (scaled)

vstd_body_length_sq – variance standardised measure of body length squared

vstd_thorax_width_sq - variance standardised measure of thorax width squared

vstd_abdomen_width_sq - variance standardised measure of abdomen width squared

PC1_sq – individual score for principal component 1 squared

BL_1 - body length measures from the original dataset

TW_1 - thorax width measures from the original dataset

AW_1 - abdomen width measures from the original dataset

BL_2 - body length re-measurements for repeatability

TW_2 - thorax width re-measurements for repeatability

AW_2 - abdomen width re-measurements for repeatability

date_photo_taken - the date the photo was taken

photo_ID - the name of each raw photograph

measure_type - brief description of the body size measure type

measure_mm - the body size measures in one column as the Image J output

Notes or notes - this variable describes the reason behind why body size measurements are missing for each individual. Only individuals where an error occurred during photography or if they flew away will have a note in this column. The others are not relevant, hence left blank (see below). 

NA s and blanks explained

In the variables containing body size measures,  'NA' s represent 'not available'/ missing data due to errors during photography - either the ventral side of the bug was forgotten to be photographed or the bug flew away before being photographed - which information is available in the notes variable in the ‘Spilostethus_pandurus_wild_caught_final_dataset.csv’ and ‘Lygaeus_creticus_wild_caught_final_dataset.csv’ final datasets.

In other variables such as 'pair_ID', NA s represent 'not applicable' as these individuals were not paired.

In the notes variable, blank rows represent 'not relevant' hence left blank. 

Raw data:

All raw photographs are provided in the folder named 'Raw_Data_Photos' under the zip file 'Raw_Data_Photos.zip' . Within this folder, the photos are organised in several other folders. First, they separated by species 'Spilostethus' and 'Creticus', and then by the date the photos were taken, such as '11-05-24 Spilo' or '31-05-24 Creticus'.

Code/software

To view and extract data from the the .arw images (raw images), the plugin Mica Toolbox in Image J software can be used, as well as Image J by itself by selecting import ARW image. Alternatively, to view the images only, RawTherapee, GIMP with a RawTherapee plugin can also be used.

R- Scripts for the data analyses can be found in in the folder 'R_Scripts' in the zip file 'R_Scripts.zip'. All scripts were produced in R-Studio 2024 version 4.3.3 (R Core Team, 2024)

The three scripts provided are as follow: ‘Spilo R analyses for manuscript’ for S. pandurus data analyses, ‘Creticus R analyses for manuscript’ for L. creticus data analyses and 'Spilo_field_repeatability' for the body size measures repeatability analysis. 

Access information

Other publicly accessible locations of the data, excluding the raw photos:

• https://doi.org/10.17630/09878f60-1a55-4042-bb20-f89d6f4c9a09