Scientific Name Extatosoma tiaratum
Conservation Status Not Evaluated
The spiny leaf stick insect is generally a tan colour across their whole body. Diet and environmental factors can lead to them appearing green, red, brown, white or yellow.
They exhibit pronounced sexual dimorphism. The females have a thick body which is longer than the male who is quite slender. Females have small wings while those of males are quite large. Covering most of their body are a series of spikes. On the male the abdomen is smooth while that of the female is spiky.
Females average a weight of 25g (0.9oz) with one specimen reaching 32g (1.12oz). Males may be just half this weight. Females may grow to 20cm (5-8in) long while average male is 10cm (3.93in).
An average spiny leaf stick insect will live for up to 1 year but some specimens can live for up to 2 years.
Spiny leaf stick insects are herbivores. Their preferred browse item is eucalyptus. They also feed upon guava, tree Lucerne, wattle, oak, rose, raspberry, hawthorn, salmon berry and bramble. The different leaves can impact upon their colour and how large they will grow.
Australia is the native home of the spiny leaf stick insect. Here they are found in the states of Queensland and New South Wales along the coast.
They live amongst the vegetation in tropical rainforest, temperate forests and grasslands.
Spiny leaf stick insects can breed through sexual reproduction and by parthenogenesis, a process where the females fertilise their own eggs. Eggs which are sexually produced will hatch quicker than those birthed through parthenogenesis. Eggs hatched parthenogenically will also produce only females. It is possible for up to 500 eggs to be laid by one female.
On the end of the eggs is a small knob known as the capitulum. This is considered edible by redheaded black ants. They will carry the eggs back to their burrow where they eat the capitulum and then they leave the eggs in the burrow. This protects them from predators. Eggs are coloured brown and cream.
Upon hatching the spiny leaf stick insect resembles a redheaded black ant more than a stick insect. It allows them to leave their burrow with the ants in safety until they find a nice tree in which to take up residence.
As they grow they moult their skin to allow their body to expand in size. It will take 6 months for them to reach full size. During this time, they will moult 6 times. Should they lose a leg this is regrown during the moulting process.
To avoid detection by predators the spiny leaf stick insect will blend in with their environment and sway like a leaf. If detected they will curl their tail back over their body so they look like a scorpion.
As young insects, they are quite active. As they grow they begin to spend more of their time being still.
When disturbed the spiny leaf stick insect emits an odour which smells like peanut butter, vinegar and toffee. This is used to deter predators.
They are a commonly kept species around the world.