Small cylindrical galls with fluted surface arising mostly from ruptured upper surface of leaves. Some were a deep purple in colour. The free ends of the galls were flat in most.
Spotted on the leaves of a peppermint gum Eucalyptus radiata in a fauna & flora reserve. ( Langwarrin)
These seem to be male galls of the eriococcid scale insect. Female galls would look very different to males.
Other galls were seen on the same tree; these had thick base with tapering free ends- these were female galls.
Thanks to Penelope Mills for the ID and confirming host species. Family: Eriococcidae