There were large numbers of these very small beetles on the Myoporum insulare on Providence Road adjacent to Woodlands Historic Park. (These were planted by the council and do not occur in the Park.) I believe the enlarged hind tibia identifies it as a flea beetle, tribe Alticini, which narrows it down to one of 232 species according to AFD
Colony of Red-line Gumtree Hoppers at the base of a ca. 7 year old Yellow Box (approx 10cm trunk diameter). There were also a few individuals and pairs dispersed on a low branch. There were no ants in attendance so it appears the bugs are not feeding, but they must be at least preparing to mate. The male in the second photo is holding onto the female with his middle legs while vibrating his front and backs legs, usually not touching the female. Many pairs in the main group were behaving in a similar way with varying degrees of contact. In one pair the male had his hind legs stationary but was stroking the "face" of the female with his front legs.