DOI: 10.5061/dryad.rd304
title: Data from: Multiple post-mating barriers to hybridisation in field crickets

description: Mechanisms that prevent different species from interbreeding are
 fundamental to the maintenance of biodiversity. Barriers to interspecific
 matings, such as failure to recognize a potential mate, are often
 relatively easy to identify. Those occurring after mating, such as
 differences in the how successful sperm are in competition for
 fertilisations, are cryptic and have the potential to create selection on
 females to mate multiply as a defence against maladaptive hybridization.
 Cryptic advantages to conspecific sperm may be very widespread and have
 been identified based on the observations of higher paternity of
 conspecifics in several species. However, a relationship between the fate
 of sperm from two species within the female and paternity has never been
 demonstrated. We use competitive microsatellite PCR to show that in two
 hybridising cricket species, Gryllus bimaculatus and G. campestris,
 sequential cryptic reproductive barriers are present. In competition with
 heterospecifics, more sperm from conspecific males is stored by females.
 Additionally, sperm from conspecific males has a higher fertilisation
 probability. This reveals that conspecific sperm precedence can occur
 through processes fundamentally under the control of females, providing
 avenues for females to evolve multiple mating as a defence against
 hybridization, with the counterintuitive outcome that promiscuity
 reinforces isolation and may promote speciation.
description: Tyler_et_al_genemapper_samplesGenemapper output for spermathecal and offspring samples from each triad. Female.ID: A unique ID number given to each female, here used to identify triads. Sample.type: For each triad DNA from the spermatheca and offspring were extracted. These are given as ‘sperm’ or ‘nymph’, respectively. Plex: Samples were screened with either individual markers or as plexes (details of microsatellite screening conditions are given in the supporting information ‘S2_Suppinfo’). Dye: The dyes used in the microsatellite screening. Blue (B), Green (G) or Yellow (Y). Allele1 / Allele2: The unique allele identified for each male in the triad. Size1 / Size2: Peak height of an allele. Area1 / Area2: Peak area of an allele.Tyler_et_al_genemapper_standardsGenemapper output for the standards used to create a standard curve for each triad. Female.ID: A unique ID number given to each female, here used to identify triads. Plex: Samples were screened with either individual markers or as plexes (details of microsatellite screening conditions are given in the supporting information ‘S2_Suppinfo’). Dye: The dyes used in the microsatellite screening. Blue (B), Green (G) or Yellow (Y). Allele1 / Allele2: The unique allele identified for each male in the triad. Size1 / Size2: Peak height of an allele. Area1 / Area2: Peak area of an allele. Standard: The percentage of DNA from the focal male added to the mix of DNA from both males.Tyler_et_al_standard_curvesDetail of the standard curves calculated from the Genemapper output. Female.ID: A unique ID number given to each female, here used to identify triads. Equation: The equation describing the fit of the curve through the standards for each triad. R-squared: The R-squared value for each standard curve.Tyler_et_al_triad_dataDetail of the individuals used in mating trials, male success in sperm storage and siring offspring, the number of eggs laid, and the percentage of nymphs that hatched.