Hi Jenny I've added this sighting in your name, using your photo from the Eriococcus coriaceus sighting (4176686). My intention is to illustrate this genus. Thanks for this discovery.
Thanks for all the information. I thought it was just some damage on the tree caused by the scale. I was going to spray the scale with white oil next week, but now I will check the tree carefully to see if there are any more of these or the caterpillars or moths. Is the red lump the chrysalis or the egg case? I think there might be a hole in the base, so it has probably been vacated.
It is a protective case for the larvae. Mine was crawling around slowly tho the rest of its body was hidden. An interesting example: http://lepidoptera.butterflyhouse.com.au/acon/coccophaga.html