The Passionvine Hopper, Scolypopa australis, is a fairly common garden and orchard bug that belongs in the Ricaniidae insect family. These little planthoppers can sometimes breed up in great numbers and wreak havoc in gardens all over Australia.
They are sap suckers and they excrete honeydew which is a diet item for other invertebrates, and for birds, etc. If the honeydew is not eaten it can produce a sooty mould infestation.
I was a little surprised to come across a few on the underside of some water-ferns I was checking recently in the Nangara reserve. The Passionvine Hoppers seemed to be enjoying the fronds of the Gristle Fern in particular.
I’m guessing the scrub birds in the gullies help keep the Passionvine Hoppers under control a bit, resulting in the likelihood of mould infestation to be pretty minimal.