In meiosis, a precursor cell -- primordial germ cell -- produces four spermatozoids during spermatogenesis, while only one oocyte is formed during oogenesis (the other three cells die during the process).
Most of the gene products used by the embryo at these stages are already present in the unfertilized egg and were produced by maternal transcription during oogenesis.
Studies show that the mourning cloaks use endocrine mechanisms similar to other lepidopterans to regulate female specific protein synthesis, oogenesis, and male and female reproductive gland development.