Most of the endemic Australian scale species cause little damage to their host plants. Some of the introduced species however can cause significant damage to crops. Often crop loss is due to the honeydew that is secreted by the scale that a black sooty mould then grows on. This affects the ability to sell the fruit.
#1. Late May 2014
Hobart
#2. Early March 2014
Conningham Nature Reserve
on Native Hop (Dodonaea viscose)
. 
#3. Mid March 2016
Denison Beach
On the weed Myrtle Leaf Milkwort (Polygala myrtifolia)
. 
#4. Mid February 2020
Peter Murrell Reserve, Blackmans Bay
On Blackwood (Acacia melanoxylon)
Large white structures are the ovisacs of the female, and the tortoise like “scales” are the males.
Identification and information thanks to Lyn Cook
#6. Late June 2012
Knocklofty Reserve, Hobart
Associated with Acacia dealbata
#6. Late January 2023
Waterworks Reserve, Dynnyrne
References
CSIRO, 1990. Insects of Australia, Volume 1: A Textbook for Students and Research Workers. 2nd Edition. Melbourne University Publishing.