Developing embryo in vitellarium of a viviparous parthenogenetic aphid female of Uroleucon tanaceti (Linnaeus, 1758) (after Uichanco 1924, with modifications of Hagan 1951).

 
 
  Part of: Gavrilov-Zimin IA (2021) Egg retention, viviparity and ovoviviparity in Paraneoptera. Comparative Cytogenetics 15(3): 239-252. https://doi.org/10.3897/CompCytogen.v15.i3.70216