Sexual dimorphism requires gene expression regulation in developing organisms. Differential expression, alternative splicing and transcript-transcript interactions all contribute to developmental differences between the sexes. However, few studies have described how these processes change across developmental stages, or how they interact to form co-expression networks. We compare the dynamics of all three regulatory processes in the sexual development of the model parasitoid wasp Nasonia vitripennis, a system that permits genome wide analysis of sex bias from early embryos to adults. We find relatively little sex-bias in embryos and larvae at the whole-gene level, but several sub-networks show sex-biased transcript-transcript interactions in early developmental stages. These provide new candidates for hymenopteran sex determination, including histone modification genes. In contrast, sex-bias in pupae and adults is driven by wholegene differential expression. We observe sex-biased splicing consistently across development, but mostly in genes that are already biased at the whole-gene level. Finally, we discover that sex-biased networks are enriched by genes specific to the Nasonia clade, and that those genes possess the topological properties of key regulators. These findings suggest that regulators in sex-biased networks evolve more rapidly than regulators of other developmental networks.(Chang et al. 2011; Innocenti and Morrow 2010 but see Wang, Werren and Clark 2015). However, the focus on adult gene expression does not reveal sex differential processes during development, and several genes are sex-biased only during those early stages (Perry, Harrison, and Mank 2014;Mank et al. 2010;Zhao et al. 2011). Changes in sex-bias expression of the same gene across development are most likely to create conflict, since the same locus may be under selection for changes in female-specific and male-specific functions in different developmental stages -a scenario that we term 'developmental sexual conflict'. Several studies have also shown that alternative splicing can show sex-bias (Telonis-Scott et al. 2008;Hartmann et al. 2011; Brown et al. 2014), and that sex-biased splicing affects sex determination (Verhulst et al. 2013; Verhulst, Beukeboom, and van de Zande 2010) and sexual development (Chang et al. 2011).The co-expression of multiple genes can result in effects that are qualitatively and quantitatively different from the sum of the effects of each gene (Ament et al. 2012;Spitz and Furlong 2012;Boyle et al. 2014), and provides a largely unexplored mechanism for the regulation of sex-specific differences; the same group of genes can have identical expression levels in males and females, yet still cause a sex-specific effect if they are only co-expressed in one sex (Arnold, van Nas and Lusis 2009;). These interactions are therefore impossible to detect by independently testing transcripts, but can be identified via differential correlation analyses on transcriptional modules, or differential cluster correlations (Tesson...