Illawarra invertebrates

Invertebrates are such a large and varied group of species that this brief discussion required many generalisations and omissions. Invertebrates lack a backbone so range from microscopic animals that live in the soil to large butterflies and include insects, worms, snails and all those marine animals such as jellyfish, starfish and sea urchins. 97% of all animals are invertebrates and of this about 77% are insects and of this about 44% of all insects are beetles. In this brief review I exclude marine species but focus on the more common species that people may see or want to encourage onto their property. You could spend your life documenting the area’s invertebrates. Fortunately when I was doing Zoology at the University of New South Wales there was a third year course on insect structure and taxonomy. Few tertiary institutions now offer a course on this group of animals. Being a herpetologist and lifting tonnes of rock and fallen timber I have inadvertently come across many interesting invertebrates.

One of the more striking local invertebrates is the Hibiscus Harlequin Bug. As its name suggests, it feeds on Hibiscus species among others. Image by Keith Horton.

Urban invertebrates

As someone with intestinal parasites once said, I have a soft spot for worms. However, few people know that our regular garden worms (Tigers (Eisenia fetida) and Reds (Amynthas corticis) are exotic! The native worms generally live deeper in the soil and are mostly in the genus Anisochaeta. The Red Quirt Worm (Didymogaster sylvaticus) is common in the Illawarra’s northern suburbs living under rocks and logs. On the red volcanic soils on Saddleback a giant worm Notoscolex grandis exists that grows to over a metre in length. These worms may only come to the surface after flooding rain but their tell-tale castings are obvious on lawns.

For most people the word invertebrate conjures up images of butterflies and beetles. Common conspicuous species of butterfly in the region include the Orchard Swallowtail (Papilio aeges). But there are other species of butterfly that eat the leaves of citrus including the Dainty Swallowtail (Papilio anactus). The planting of lemon trees and other species of exotic citrus has certainly allowed these species to spread along the east coast.

Male (l) and female (r) Orchard Swallowtails have quite different markings on their wings. Image by Garry Daly ©.

Other common butterflies seen in urban areas include the Blue Triangle (Graphium euryplus), Macleay’s Swallowtail (G. Macleayanum), Chequered Swallowtail (P. demoleus), Tailed Emperor (Charaxes sampronius) Monarch (Danaus plexippus), Common Jezebel (Delias nigrina), Pencilled Blue (Candalides absimilis), Orange Palm Dart (Cephrenes augiades), Australian Painted Lady (Vanessa kershawi) and Meadow Argus (Junonia villada). Common moths in our area include species of hawk moth (Psilogramma casuarinae and Hippotion boerhaviae). When I was a child growing up in Sydney the street-planted Brush Box supported populations of Emperor Gum Moths (Opodiphthera eucalypti) and Cup Moths (Doratifera vulnerans). Unfortunately these species are much less common today. A beautifully coloured animal is the Joseph’s Coat Moth (Agarista agricola), which has its southern limit in the Illawarra and being diurnal can be seen at times in Wollongong Botanic Garden where it feeds on the Slender Grape (Caryratia clematidea). The caterpillars of this moth are boldly banded black and white.

The Joseph's Coat Moth caterpillar feeding on Slender Grape (Cayratia clematidea). The moth helps keep the plant in check. Image by Carl Glaister ©.

Another creature that feeds on Slender Grape, the Impatiens Hawk moth caterpillar. Image by Tracee Lea ©.

Beetles are the most common invertebrate and Australia has over 23,000 described species! The commonly seen beetles are those associated with summer: the Christmas Beetles, but others that people are aware of include the various species of Longhorn (family Cerambycidae) whose larva bore into the stems of trees and often damage or kill them and the Dendrobium Orchid Beetle (Stethopachys formosa). Another common Beetle seen during summer is the Botany Bay Diamond Beetle (Chrysolopus spectabilis) this beautiful blue and black insect can be seen on wattles. Females bore holes in the base of the wattles (particularly Black Wattle (Acacia mearnsii)) and lay eggs in these. The grubs bore deeper into the roots of the plant.

Some species of Longhorn Beetle (Hesthesis spp.) mimic wasps, in both appearance and behaviour, as a defense against predators. Image by Garry Daly ©.

Rural invertebrates

For people on the land the word invertebrate may conjure up images of ticks and leeches. The Paralysis Tick (Ixodes holocyclus, also known as the Shell Back, Blue Bottle and Grass Tick) affects humans and domestic pets. They feed on native mammals and in areas with an abundance of wallabies and/or bandicoots the ticks may also be common.

Leeches are in the same taxonomic group as earthworms being segmented worms. The species most commonly found in the Illawarra that bite humans is Chtonodbella limbata but there is also a larger aquatic species the Tiger Leech (Richardsonianus australis). Chtonodbella limbata can attain high densities on the edge of rainforest where there is an abundance of native mammals. There are many other species of leeches that do not bite humans. Human v/s leech interactions are generally negative. I once had a leech slip behind my eyeball and sucked blood from that area. When it became engorged I had someone pull it out and had to hold my eye in place otherwise it may have come out with the leech.

On rural land which supports native vegetation there is a much greater chance of rotting fallen logs, large trees with decorticating bark peeling away from the trunk, loose surface rock, dams and creeks that can support a wide range of invertebrates. Some of my favourites that live in rotting timber are the Green and Golden Stag Beetle (Lamprima latreillii), Brown Stag Beetle (Ryssonotus nebulosus), Bess Beetle (Aulacocyclus endentulus) and the Wood Cockroach (Panesthia cribrata).

The Brown Stag Beetle has antler-like antennae. Image by Garry Daly ©.

Spiders are a group of invertebrates that for most people hold little interest, having to contend with the Black House Spider (Baduma insignis) and the exotic Daddy Long-legs (Pholcus phalangioides). People generally dislike the big black spiders that build tunnels in the ground such as the Funnel Web (Atrax robusta) and members of the genus Hadronyche. I recall digging barefoot in a garden at Stanwell Park and could feel something wriggling under one foot. When I stood aside I found that I had chopped off the abdomen of a huge Funnel Web and the damaged animal was biting the ground. There are two funnel-web type spiders in our region that have very limited distributions: one is the Illawarra Funnel Web (Illawarra wisharti) and the Tube Spider (Misgolas robertsi).

Golden Orb Spiders are found in urban as well as rural areas. This shot shows a female and a (much
smaller) male above her. Image by Garry Daly ©.

The Funnel Web Spider, a much disliked species of spider. Image by Garry Daly ©.

Net-casting Spiders don't spin webs, but instead catch their prey by throwing a small woven net over it. Image by Emma Rooksby.

Cicadas are found in rural and urban areas being a feature of our summer soundscape. In the Illawarra there are quite a few species but not many people would not know they are bugs and like their citrus stinking cousins have a long tubed mouth to suck sap from trees. The most commonly known species is the Green Grocer (Cyclochila australasiae) that comes in a number of colour forms known as the Yellow Monday and Blue Moon. Other species include the Double Drummer (Thopha saccata), Red-eyed Cicada (Psaltoda moerens) and Floury Baker (Abricta curvicosta). The Bladder Cicada (Cytosma saundersii) has a natural distribution north of Newcastle but has spread south due to the larvae living in pot plants. I have no records of this species in the Illawarra but it is probably here.

Many insects have larva with aquatic life histories. These include dragonflies, damselflies, mayflies, caddisflies, stoneflies, dobsonflies, lacewings and scorpionflies. Then there are those whose adults live in water. These include the various types of predatory water beetles and backswimmer bugs. The region also supports a number of yabbies including several native species of Euastacus (including E. australasiensis, E. hirsutus and E. spinifer) and Cherax destructor, which is widely used as a food species and put into dams. Cherax destructor outside its natural range west of the dividing range is a threat to native frogs as it eats tadpoles and frog eggs.

The Blue Mountains Firefly (Atyphella lynchus) has its southern limit in the Illawarra at Tapitallee. The adults have a very restricted season, being seen for just a few weeks in late November and early December. They live in moist rainforest gullies, and their larvae feed on snails. They hunt by following the slime trail to the prey, which is seized, injected with poison and eaten (Australian Museum website).

Some invertebrates such as termites, bees and ants form colonies that function like super-organisms. For ants and bees there is a queen that lays the eggs, while workers that are sterile females gather the food. The workers only have half the genetic constitution of the queen (hence their sterility), and the theory is that they give up their ability to reproduce because they share all their genes with the queen. The queen's genetic output is equivalent to that of her workers if they were fertile. The drones are males and only a few are allowed to exist in the colony as they contribute little to the general welfare of the colony.

While there are over 200 different species of native bee in the Illawarra, only the Stingless Bee (Tetragonula carbonaria) nests in a hive, while the rest are solitary. You can buy colonies of Stingless Bees; as they are essentially a tropical species it is best to locate the nest in a north-facing sunny area, out of the wind. The other, solitary species, make individual nests in a range of materials including dead plant stems, holes in trees, mud or in the ground. Species such as the Blue-banded Bee (Amegilla cingulata) and Teddy Bear Bees (Amegilla bombiformis) are probably the most conspicuous.

Useful plants to attract invertebrates

Scientific name	Common name	Fauna attracted
Acacia longifolia subps. longifolia	Sydney Golden Wattle	Jewel Beetle larvae eat leaves
Acacia maidenii	Maiden’s Wattle	Tailed Emperor larvae eat leaves
Acacia mearnsii	Black Wattle	Fiery Jewel Butterfly larvae eat leaves, Botany Bay Diamond Beetle adults eat sap
Alectryon subcinereus	Native Quince	Eastern Flat butterfly larvae eat leaves
Allocasuarina littoralis	Black Oak	Used by Jewel Beetles
Archontophoenix cunninghamiana	Bangalow Palm	Orange Palm Dart butterfly larvae eat leaves
Baeckea spp.		Flowers attended by Jewel Beetles
Brachychiton acerifolius	Flame Tree	Leaves eaten by Tailed Emperor, White-banded Plane & Common Pencilled-blue butterflies
Brachychiton populneus	Kurrajong	Leaves eaten by Tailed Emperor butterfly, Eastern Flat butterfly
Breynia oblongifolia	Coffee Bush	Leaves eaten by Large Grass Yellow butterfly
Bursaria spinosa	Blackthorn	Flowers attended by many species of insects
Callicoma serratifolia	Black Wattle	Leaves eaten by Eastern Flat Butterfly larvae
Caryratia clematidea	Slender Grape	Joseph’s Coat Moth and Impatiens Hawk Moth larvae
Cassinia sp.	Cassinia	Flowers attended by Jewel Beetles
Ceratopelatum gummiferum	Christmas Bush	Flowers used by Consimilis Blue butterfly
Cinnamomum oliveri	Oliver’s Sassafras	Leaves eaten by Blue Triangle butterfly larvae
Coprosma quadrifida	Native Currant	Leaves eaten by Coprosma Hawk Moth larvae
Cryptocarya glaucescens	Jackwood	Leaves eaten by Orchard butterfly larvae
Dendrocnide excelsa	Giant Stinging Tree	Leaves eaten by Jezebel Nymph larvae
Dianella caerulea (and other Dianella species)	Blue Flax-lily	Leaves eaten by various butterfly larvae
Dodonaea triquetra	Large-leaf Hop Bush	Leaves eaten by Fiery Jewel butterfly larvae
Doryphora sassafras	Sassafras	Leaves eaten by Macleay’s Swallowtail larvae
Ehretia acuminata	Koda	Leaves eaten by Hairy Line-blue butterfly larvae
Endiandra sieberi	Corkwood	Leaves eaten by Eastern Flat butterfly larvae
Eucalyptus + Angophora + Corymbia spp	Eucalypts and Bloodwoods	Flowers provide nectar for a range of insects and sap used by cicadas
Exocarpos cupressiformis	Cherry Ballart	Leaves eaten by Wood White butterfly and Fiery Jewel butterfly larvae
Ficus obliqua	Small-leaved Fig	Leaves eaten by Australian Crow butterfly larvae
Gahnia sieberana	Red-fruit Saw-sedge	Leaves eaten by Sword-grass Brown butterfly and Flame Skipper larvae
Hibbertia scandens	Twining Guinea Flower	Leaves eaten by Impatiens Hawk Moth larvae
Coronidium and Xerochrysum species		Flowers attended by Jewel Beetles
Imperata cylindrica	Blady Grass	Leaves eaten by various butterfly larvae including Greenish Darter
Kunzea ambigua	Tick Bush	Flowers attended by many species of insects
Leptospermum spp.	Tea Trees	Flowers attended by many species of insects
Litsea reticulata	Bolly Gum	Leaves eaten by Blue Triangle butterfly larvae
Lomandra longifolia	Spiny-headed Mat-rush	Leaves eaten by various butterfly larvae
Melicope micrococca	Hairy-leaved Doughwood	Leaves eaten by Orchard butterfly larvae and flowers attract Fiddler Beetles
Notelaea longifolia	Mock Olive	Leaves eaten by Eastern Flat butterfly larvae
Poa sp.	Tussock Grass	Leaves – various butterflies including Dispar Skipper, Klug’s Xenica and Eastern-ringed Xenica, White Grasschat, Banks Brown
Podocarpus elatus	Plum Pine	Leaves eaten by Eastern Flat butterfly larvae
Polyscias elegans	Celery Wood	Flowers visited by Consimilis Blue butterfly
Rhagodia candolleana	Seaberry Saltbush	Leaves eaten by Chequered Blue butterfly larvae
Scaevola calendulacea	Dune Fan-flower	Leaves eaten by Meadow Argus butterfly larvae
Tasmannia insipida	Brush Pepperberry	Leaves possibly eaten by Macleay’s Swallowtail larvae
Themeda triandra	Kangaroo Grass	Leaves eaten by Eastern Ringed Xenica, Klug’s Xenica butterfly larvae
Xanthorrhoea spp	Grass Trees	Flowers attended by many species of insects
Zieria smithii	Sandfly Zieria	Leaves eaten by Orchard butterfly larvae