Foraging behaviours encompass strategies to locate resources and to exploit them. In many taxa, these behaviours are driven by a major gene called for, but mechanisms vary between species. In the parasitoid wasp Venturia canescens, sexual and asexual populations coexist in sympatry but differ in life-history trait, physiology and behaviours, which could impact their foraging strategies. Here, we explored the molecular bases underpinning divergence in behaviours by testing two mutually nonexclusive hypotheses: first, the divergence in the for gene correlates with difference in foraging strategies, and second, the latter rely on a divergence in whole-genome expression. Using comparative genomics, we showed that the for gene was conserved across insects considering both sequence and gene model complexity. Polymorphism analysis did not support the occurrence of two allelic variants diverging across the two populations, yet the asexual population exhibited less polymorphism than the sexual population. Sexual and asexual transcriptomes sharply split, with 10.9% of differentially expressed genes, but these were not enriched in behavioural-related genes. We showed that the for gene was more highly expressed in asexual female heads than in sexual heads and that those differences correlate with divergence in foraging behaviours in our experiment since asexuals explored the environment more and exploited more host patches. Overall, these results suggested that fine tuning of for gene expression between populations may have led to distinct foraging behaviours. We hypothesized that reproductive polymorphism and coexistence in sympatry of sexual and asexual populations specialized to different ecological niches via divergent optima on phenotypic traits could imply adaptation through different expression patterns of the for gene and at many other loci throughout the genome.

In a behavioural experiment, the foraging behaviours of 34 parasitic wasps (17 sexual and 17 asexual) was recorded in the laboratory. On the same individuals, the expression of the for gene was quantified by qPCR. All corresponding measures are stored in the table 'for_foraging_34.txt'. This file was then analysed with R using the script 'script_foraging_for.R'. Transcriptome from sexual (3 RNA-seq libraries) and asexual (3 RNA-seq libraries) female heads have been sequenced and mapped (raw data accessible in GEO GSE194171). After mapping, transcript-aligned reads were counted in the file 'Vcan_countTable.txt'. This table was then analysed with the script 'transcripto_SexAsex.R', using R and the metadata contained in the file 'metadata.txt'. Full details on data acquisition and analysis are described in the materials and methods section of the article entitled 'The for gene as one of the drivers of foraging variations in a parasitic wasp'.

All files can be opened and read with any text editor. Scripts can be executed with R, an open-source software.