Australia has plenty of native ladybirds, but this amorous pair belong to the European white-collared or spotted amber ladybird (Hippodamia variegata). First recorded in Australia in Gatton (SE Queensland) in 2000, the species is now widespread and is used in biological control of aphids and psyllids.
Although the background colour and the number and shape of the markings are variable, the white-collared ladybird is distinguished from native species by the white yoke on the pronotum (the 'shield' between the head and the wingcases).
Franzmann, B.A. (2002). Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), a predacious ladybird new in Australia. Australian Journal of Entomology 41 (4): 375 – 377.