DOI: 10.5061/dryad.s1rn8pkbh
title: Sexual selection on a female copulatory device in an insect with nuptial gifts

description: Male genitalia are rapidly evolving structures, often driven by sexual
 selection to increase fertilization success. Although sexual selection on
 females can be strong in systems where males provide offspring care or
 feed their mates, sometimes resulting in the evolution of female
 ornamentation, there are no actual estimates of direct sexual selection on
 female genitalia. In a New Zealand ground weta, Hemiandrus pallitarsis
 (Orthoptera: Ensifera, Anostostomatidae), females possess a genitalic
 device (the accessory organ) that is necessary for successful copulation
 and the acquisition of glandular food-gifts from males. These nutritious
 gifts are known to result in sexual competition among females in other
 ensiferan species. In ground weta, the gifts are probably important in
 avoiding starvation during a months-long period when caring for (their
 lifetime production of) eggs and offspring. Here, we test the hypothesis
 that the accessory organ is a sexually selected device in H. pallitarsis
 by measuring the female Bateman gradient, Jones index, and directional
 sexual selection on the accessory organ. Using newly developed and
 characterized microsatellite loci, we analyze offspring and/or stored
 sperm to estimate female mating frequency for the first time in ground
 weta. As predicted, we found both a positive Bateman gradient and Jones
 index for females, and evidence of directional sexual selection on
 accessory organ length. Although organ length does not correlate well with
 female fecundity, it may increase mating success by indicating her
 condition and thus quality of her offspring care.
description: Excel, R studio
description: ## Genetic data.xlsx Includes multiple sheets containing all genetic data:
 **-Sheet "population genotypes"** contains all genotypes from
 our two collection sites, used to characterize loci (Genepop 4.7; results
 included in ESM 1) and to inform parentage analyses (Software GERUD).
 **-Sheets "KA", "KB", "PA", "PB",
 "PC", "PD", "PE", "PF",
 "K2A", "K2D", "K2E", "K2G",
 "K2J", "P2B", "P2C", "P2E", and
 "P2G"** each represent a different weta family and contain
 Genotypic data for offspring, their mother, and one potential father, the
 "last male". These data were used to estimate female mating
 success (using GERUD to detect discrete sires) for Bateman gradients and
 Jones index. In the above sheets, data are provided per specimen in rows,
 with separate columns for microsatellite loci, each containing 2 alleles.
 Alleles are shown as 3-digit numbers which represent the lengths (number
 of base pairs) of the DNA fragments. Samples beginning with "K"
 or "W" were collected from Kiriwhakapapa and samples beginning
 with "P" or "N" were collected from Palmerston North.
 "null" indicates undetected alleles. **-Sheet "Sperm
 stores_bateman"** contains the alleles detected in the stored sperm
 of females at each locus. Used to estimate female mating success for
 measures of Bateman gradients and Jones index (in combination with
 offspring data). **-Sheet "Sperm stores_accessory organs"**
 contains the alleles detected in the stored sperm of females at each
 locus. Used to estimate female mating success for directional selection on
 accessory organs. In the above sheets, data are provided per specimen in
 rows, with separate columns for collection location and microsatellite
 loci, each containing 1-10 alleles. Alleles are shown as 3-digit numbers
 which represent the lengths (number of base pairs) of the DNA fragments.
 "null" indicates undetected alleles. ## Bateman\_data.xlsx
 Includes data for all analyses and figures (Figure 3) regarding the
 Bateman gradient and Jones Index. Size was determined by measuring the
 length of the pronotum, Number of offspring (total and developed) were
 counted and estimates of mating success (number of mates) were obtained
 from genotypic data of offspring and stored sperm. -**Sheet
 "bateman"** contains all data used to calculate pooled Bateman
 gradients and Jones Index. -**Sheet "bateman02"** contains data
 used to calculate Bateman gradients for the year 2002. -***Sheet
 "Bateman17**"* contains data used to calculate Bateman gradients
 for the year 2017. In all sheets, each row contains a specimen with
 columns showing: Collection year, collection location (K indicates
 Kiriwhkapapa; PN indicates Palmerston North), body size (pronotum length;
 in mm), and our two measures of reproductive success. Any blank cells
 indicate missing data, and must be left empty to facilitate
 standardization of data. R code is set up to calculate relative
 (mean-standardized) values for body size, mating success, and both
 measures of reproductive success in Columns 8-11, therefore
 "TBD" is used as a place holder. ## Sexual\_selection.xlsx
 -**Sheet “females.ss”** includes phenotypic data used to measure
 directional sexual selection on accessory organs (estimates of mating
 success determined from alleles found in stored sperm) and the
 relationship between accessory organs and fecundity (number of eggs in the
 abdomen). Each row contains a specimen with columns showing: Collection
 location (K indicates Kiriwhkapapa; PN indicates Palmerston North),
 Collection year, body size (pronotum length; in mm), accessory organ
 length (in mm), accessory organ width (in mm), and mating success, and
 fecundity. Any blank cells indicate missing data, and must be left empty
 to facilitate standardization of data (as per R code). ##
 R\_code\_acessory\_organs.R Includes the script for all analyses and
 graphs included in the article: **Female Bateman gradients** contains code
 used to determine Bateman gradients (linear regression of mating success
 and reproductive success), using total eggs laid and those that developed
 to the nymphal stage. Next is the analysis of bateman gradients that
 include body size as well as interactions with collection site and year.
 Next is code used to make Figure 3 displaying bateman gradients. Uses
 datafile “bateman”. Next are Bateman gradients separated by collection
 year for both measures of reproductive success. Uses datafiles “bateman02”
 and “bateman17” **Jones Index** contains calculations for Jones Index
 (also determined using Batemanator). We first calculate the variance in
 relative mating success and then multiply this by each bateman gradient
 (regression coefficient of mating success and reproductive success) to
 determine the Jones index. Uses datafile “bateman”. **Sexual selection on
 accessory organs** contains all code used to measure sexual selection on
 accessory organs (multiple linear regression of accessory organ traits and
 mating success). It includes the MLS regression model reported in the text
 as well as a linear mixed model which includes site as a random effect
 (singular fit). Next are graphs used to visualize differences between
 collection sites, and regression models that test for an interaction with
 each of our trait variables. Next are plots for each trait that display
 variation between sites (included in ESM 1). Uses datafile “females.ss”
 **Relationship with number of eggs** contains all code used to measure the
 relationship between accessory organs and fecundity (multiple linear
 regression of accessory organ traits and number of eggs in the abdomen).
 It includes an MLS regression model as well as the linear mixed model
 reported in the text (site as a random effect). Next are graphs used to
 visualize differences between collection sites, and regression models that
 test for an interaction with each of our trait variables. Next are plots
 for each trait that display variation between sites (included in ESM 1).
 Uses datafile “females.ss”