Many years ago, this unmistakable species was included in the genus Myopsocus. Later, it was transferred to the horribly-named genus Phlotodes (which sounds to me like something you might find honked into a handkerchief); it stayed in that genus for a few years before being shifted back to Myopsocus. Now, apparently, someone has moved it to the genus Nimbopsocus, a name roughly ten times longer than its owner even without the part that identifies the species: australis.
What often strikes me about these kinds of tiny creatures is the way they're unknown to most people. I'd be amazed if the number of New Zealanders who'd ever noticed Nimbopsocus australis  got beyond double figures. This species is fairly easy to find: just look closely at anything with a good growth of lichen and eventually you're likely to see either the adults or the herds of nymphs (which cluster in mobs like tiny wildebeest, grazing on algae, fungi and lichen). But who bothers to look? A few oddballs like me; weirdos who get more delight out of peering at lichen-encrusted fence battens and stockyard railings than polishing their Holdens; eccentrics who'd rather know about barklice than Bathhurst. They (these barklice, not me) are beautiful to look at, and the antics of the males when displaying to the females are hilarious (but the same is often true of us, although I've yet to see some bloke doubled over with his head on the ground, waving his arms in the air behind his back, and rocking from side to side).
They're not just beautiful, though: they're fascinating too. Think about everything needed to allow an insect's tiny body to be called 'alive' — the complexity of that astonishing number of structures and processes packed into something so small we overlook it unless it stings us or drowns in our soup. Despite our remarkable advances in engineering, an insect remains utterly beyond our ability to construct; compared to the little barklouse in this photograph, a V8 Supercar is about as complex as a brick.
In short, they're worth watching and thinking about (although I'm unlikely to have convinced the petrolheads  I've just antagonised). Yet hardly anyone does watch them — not just barklice, but most of the thousands of species of tiny animals that surround us every day. We don't even see them. They're out there in plain view, but functionally they're invisible.
1. Psocodea is sometimes considered a superorder comprising the order Psocoptera ('booklice' and 'barklice') and the order Phthiraptera ( parasitic lice).
2. More photographs in this NZ NatureWatch entry.
3. I'm using 'petrolhead' in the sense of definition no. 2 in the wiktionary entry.