A gathering of empty aphids that have been parasitised by something (Probably a wasp). It's interesting that they are all gathered in the same place. Woodgate, Qld.
A gall made by aphids on the petiole of a cottonwood leaf. There are immature aphids (with white waxy coats) on the outside of the gall. The aphids come and go through the slit on the side of the gall. Kyogle, NSW.