Figure 8

Schematic model of the dynamics of B. aphidicola and bacteriocyte cells during parthenogenetic development of the pea aphid.
Evolution of bacteriocyte number and organization (a), bacteriocyte size (b), or symbiont density (c), in the pea aphid body, from the late embryo to the senescent adult. In each panel the scale is constant, except for panel (a) where the embryo is 4x compared to adult aphids.