Aphid ovarioles (germarium plus embryos at different stages) after genomic Brdu incorporation. Aphids can concentrate chemicals in the hemolymph by the use of the drug delivery system described in figure 1. Animals were dissected with the aid of a microscope and the ovarioles were fixed in methanol 70% for four hours. A: ovarioles submitted to exposure of Brdu. We observe the malformation (fusion) of intermediate stage embryos (striped arrow) and the identical size of early embryos. B: control of ovarioles without chemicals. We see the well defined and successive stages of maturing embryos (spotted arrow) each one behind the other in their respective ovarioles.