Lifecycle in five pictures
The Dotted Paropsine Leaf Beetle (Paropsis atomaria), pictured below, is one of many species of Eucalyptus Beetle feeding on our gum trees at the moment. Atomaria refers to the speckled colours on the wing cases.
After mating tubular eggs are laid in a cluster around a gum twig by the female beetle. The larvae when hatched are yellow with a black head and tail and covered in small black dots.
Both the adult and larval forms are herbaceous. The larvae form groups that entirely devour young gum leaves. They pupate in the ground and emerge as adults, which feed on more mature leaves, creating semi-circular shapes in the leaf margins.
The many species of Leaf Beetle come in a range of colours. At this time of the year they provide welcome mobile tree decorations – unless you are a tree grower!
Focus On Fauna 
“they provide welcome mobile tree decorations” WHAT?! You think an invasive species that kills trees is a welcomed decoration? Did you just fall out of a tree yourself?
Hi CV, This beetle species is not invasive. It is an Australian species endemic to the east coast of Australia. They feed on the leaves of eucalypts, as do many other creatures, but they do not do enough damage to kill trees.
it’s invasive in Southern California, showing up in 2022 and wreaking gum tree havoc everywhere ever since. Trashed my eucalyptus… had to have a specialist out to inject the tree and finally have the better of these nasty, voraciously destructive bugs.
This of course is the danger of moving trees outside of their native areas, having the pests follow but not having the predators of those pests around to keep the pests in check. There are a number of famous examples in Australia where for all the right reasons foreign species have be introduced to the country with disasterous consequences.
We are having a huge heatwave in California and noticed tons of these decorations cooked on the sidewalk under the eucalyptus trees.