At Cave Creek we have more invertebrates than anything else, but we know next to nothing about them. Of the millions of invertebrate species that keep the rainforest going, we can name very few. The usual estimate, that half of Australia’s native invertebrates have yet to be described, is probably way too low. For starters, very little is known about the invertebrate population of the canopy, which is a whole other world. For the most comprehensive guide to the invertebrates of the Macleay-Macpherson overlap currently available see Geoff Williams, CERRA Invertebrates: A Taxonomic and Biogeographic Review of the Invertebrates of the Central Eastern Rainforest Reserves of Australia (CERRA) World Heritage Area, and Adjacent Regions, which can be downloaded from here.
One group of Cave Creek invertebrates is world famous; these are the so-called glow-worms, actually the larvae of a fungus gnat, Arachnocampa flava. The only other Arachnocampa species lives in New Zealand. Our most spectacular invertebrate is a crustacean, Euastacus sulcatus, the so-called Lamington Blue Crayfish (see video). Our kingfishers live on a dark blue yabby (Cherax sp.) with gold edges to its claws. Other crustaceans include water-fleas, wood-lice, land- and leaf-hoppers, and the so-called Carpet Prawn, Talitroides topitotum.
The snail fauna of Natural Bridge is among the most various in the world. The biggest is the Giant Panda Snail, Hedleyella falconeri. Of the 96 endemic mollusc species so far described, thirteen were first collected at Natural Bridge. At least two of our resident species are predatory carnivores. We have all kinds of worms, flatworms, ribbon worms, earthworms, as well as velvet worms that aren’t really worms at all. Some of our worms glow in the dark. Leeches of all sizes are always with us.
We have vast numbers of spiders too. We’re pretty sure our garden orb-weaver is Eriophora transmarina, and we have the usual Argiope species. Our hunstmen (Holconia spp.) come in various shapes and sizes, and we probably have Isopeda binnaburra, but we’re not sure. The type of one of many species of Lamponidae, the white-tailed spiders, Centrothele nardi, was found at Natural Bridge National Park. We have various wolf spiders, Kangarosa (Trochosa) spp; one of these, offically recorded as having been found at Natural Bridge, used to be called Trochosa tristicula tristicula and is now to be known as Kangarosa ludwigi. Among the mygalomorphs we have Namea spp., Ixamatus spp., Hadronyche spp., Bymainiella spp. Though no tick is listed as endemic to Natural Bridge, and we may expect that the number of ticks we have will diminish as the grass and weeds are eliminated, we have seen ticks on our pythons. These are probably Ambylomma moreliae. We must have untold billions of mites in every kind of habitat, from the tree-tops to the subsoil. Our centipedes and millipedes can be huge. We also glory in a giant earwig, Titanolabis colossea.
Of the Coleoptera we have every kind. The Belidae group of weevils are particularly interesting because they are Gondwanan survivals; one, Rhinotia ruficornis, is particularly associated with one of our tree species, Argyrodendron actinophyllum or Black Booyong, which is host also to a much rarer creature, the leaf beetle Chiloxena tuberosa. Another group of belid weevils is associated with the Araucariaceae; the small Apagobellis brevirostris and the 60mm Eurhamphus fasciculatus feed and breed on Hoop Pine (Araucaria cunninghamiana) as does the leaf-beetle Palophagus australiensis. Both species of Eupomatia rely upon weevils for pollination; the weevil was identified as Elleschodes hamiltoni, but as different species of Elleschodes appear to be involved in different areas, the taxonomy is in the process of revision.
Of butterflies and moths we have trillions, some well-known and some utterly cryptic. Some of these, like the Cedar Tip Moth, Hypsipyla robusta, we are not particularly fond of, nor do we greatly enjoy the depredations of the larvae of one of our hawkmoths, Theretra tryoni, which reduce our cunjevois to slimy rags, but their presence means that the forest community is rebuilding itself. At first the insect population explosion may threaten to overwhelm the young tree, but within a year or two the predators have moved in and a balance has been struck. At certain times of the year the Lewin’s Honeyeaters mob the Brachychitons, fishing out the fat larvae of a leaf-roller moth and stripping the trees of dead foliage.
The creature we’d most like to find at Cave Creek is an entomologist. If you’re an entomologist and you think you might like to sample this fertile hunting-ground, please get in touch at email@example.com.