[Objectives]  To determine whether the Ywhae and Notch1 genes, which play important roles in the regulation of embryo development and fertility in insects, are differentially expressed in male and female Calliptamus italicus. [Methods]  Transcriptome data of adult male and females indicated that Ywhae and Notch1 are differentially expressed in the sexes of this species. We used qRT-PCR to detect the expression pattern of these two genes in different tissues (cuticle, intestine, ovary and testis) of female and male adults, and in eggs at different stages of development. [Results]  Both Ywhae and Notch1 were expressed in different adult tissues. Expression of Ywhae was significantly higher in male than in female tissues (P<0.05). Expression of Notch1 was significantly higher in the cuticle and testes of males than in cuticle and ovaries of females (P<0.01), and significantly higher in the intestines of females than males (P<0.001). Expression of Ywhae was significantly higher in eggs in the early-stage and in post-diapause stage, than in the diapause stage (P<0.01), and was highest in the post-diapause development stage (P<0.001). The expression of Notch1 was highest in eggs in the early development stage (P<0.01), and decreased significantly after eggs entered diapause (P<0.001). Notch1 expression increased significantly after the termination of diapause (P<0.01). [Conclusion]  Both Ywhae and Notch1 are differentially expressed in the sexes of C. italicus, and both genes are involved in the development of eggs. These genes are also involved in the development of the male reproductive system in the early embryonic stage. These results may provide clues revealing the mechanisms responsible for the differentiation of the sexes in C. italicus.