Comparative study on the sex-specific photoreceptors of the compound eye in dipterous insects

The sex-specific photoreceptor central retinula cells R7 extend to ventral region from the dorsal region in male dipterous insects, including Musca domestica, Calliphora erythrocephala, Tabanus mandarinus and Atylotus miser Szilady. The rhabdom of the sex-specific central retinula cell R7 extends to the basement membrane and keeps abreast of the rhabdom of the central retinula cell R8 in male Musca domestica, Tabanus mandarinus and Atylotus miser Szilady, but does not extend to the basement membrane in male Calliphora erythrocephala. The sex-specific central retinula cells in the compound eye of the female dipteran are only distributed in the ventral region of the compound eye and are less numerous than central retinula cells R8 in the same region.