Structure of the ovaries of the primitive aphids Phylloxera coccinea and Phylloxera glabra (Hemiptera,Aphidinea: Phylloxeridae)

Ovaries of phylloxerids consist of short telotrophic ovarioles. Ovaries of wingless morphs contain four ovarioles whereas those of winged morphs contain one or two ovarioles. The individual ovariole of the adult female is differentiated into a terminal filament, trophic chamber (tropharium), vitellarium and short ovariole stalk (pedicel). The number of germ cells constituting ovarioles is not stable and ranges between 49 and 64. The tropharia enclose individual trophocytes and arrested oocytes. The vitellaria contain usually two oocytes, which develop through three stages: previtellogenesis, vitellogenesis and choriogenesis. Endosymbiotic microorganisms do not occur in the germ cells. In the light of the obtained results, the phylogenetic relationships between aphid families are discussed.