Giant Prickly Stick Insect (Extatosoma Tiaratum)

The giant prickly stick insect (Extatosoma tiaratum), also known as Macleay's spectre, is one of the most popular and commonly kept phasmid species in captivity. Native to Queensland and New South Wales in Australia, these insects are loved for their large size, calm nature, and ease of care.

Nymphs: Newly hatched nymphs are distinctive, with black and reddish bodies, orange heads, and white collars, closely resembling ants. They measure ~11-12mm in length. After several moults, they begin to resemble miniature versions of their adult counterparts. In rare instances, giant prickly stick insects may display a 'lichen form', featuring stunning white to white-green colouration with black highlights. To increase the likelihood of this colouration, lichen can be placed in their enclosure from the nymph stage. They mature to adulthood after about 5 months and 5-6 moults.

Females: Adult female giant prickly stick insects are covered with thorn-like spikes, resembling jagged autumn leaves. They have long, rounded, bulky bodies, growing to approximately 130-150mm in length. Large lobes adorn each of their legs. Their colouration is typically sandy-brown, though darker brown or green varieties exist. Adult females also possess small, non-functional wings and antennae ~25mm in length.

Males: Adult males are smaller and thinner, growing to approximately 90-100mm in length. Unlike females, males lack thorn-like spikes. They have long, functional wings that extend past the abdomen, making them capable flyers. Males also possess much longer antennae than females.

Females live for ~14-18 months.

Males live for ~6-12 months and mature faster than females.

The giant prickly stick insect, like most phasmid species, is naturally docile and nocturnal, becoming active at night for feeding and movement. Despite their generally calm nature, these insects have developed interesting defensive behaviours.

When threatened, both males and females adopt a distinctive 'scorpion-like' pose, standing on their front and middle legs while pointing their abdomen up or to the side. Interestingly, this posture isn't solely defensive, as they often sit passively with their abdomen curled over. A fun fact: due to this scorpion-like appearance, they were used in the film 'Indiana Jones and the Temple of Doom' as fake scorpions. If disturbed, adult males readily take to the air. Alternatively, they may play dead, lying motionless on their backs.

This species requires careful handling, as their sharp spines can prick the skin.
Exposure to air movement results in the phasmid actively swaying back and forth or side to side, mimicking foliage rustling in the wind.

Newly hatched nymphs can exhibit hyperactive behaviour. This initial burst of activity gradually settles as they acclimate to their environment and begin to adopt the more sedate behaviour characteristic of the species.

Giant prickly stick insects primarily feed on bramble, raspberry, rose, oak, hazel, and eucalyptus species. When selecting food plants, ensure they are free from insecticides or other harmful chemicals.

Before offering food to your phasmid, it's advisable to wash the cuttings with water.

To maximise plant longevity and minimise maintenance, consider keeping the food plant in a pot of water within the enclosure. However, take care to cover or reduce the size of the pot's opening to prevent the phasmids from accidentally falling in and drowning.

Always provide a fresh source of food. On average, clean out the enclosure once a week, replacing old food with fresh offerings and adding new substrate to remove waste. This weekly maintenance is also an ideal time to collect any eggs that have been laid.

The giant prickly stick insect thrives in a spacious and warm environment.

Temperature: Maintain temperatures between 20°C to 30°C. Room temperatures are usually sufficient for this species. The warmer they are kept, the quicker they develop.

Humidity: This species is not as demanding in terms of humidity as other phasmids. Nevertheless, you should aim for humidity levels of 60-70% to assist with moulting and provide drinking water. Spray the enclosure once daily, focusing on the food plants. Use non-chlorinated water to avoid potential harm. Proper moisture is essential for the phasmid's growth and development. To maintain high humidity, consider using paper towels or coir (coconut fibre) as a substrate.

Lighting: Mimic natural day/night cycles using either natural or artificial lighting.

Provide an enclosure at least three times the insect's length in height and twice in width. A minimum enclosure size of 30cm x 30cm x 45cm (width x length x height) is recommended. As this is a larger species, their living space should reflect their size. Additional height is beneficial, as it provides sufficient space for the insects to hang vertically during moulting.

It's important to implement secure, strong branches throughout the enclosure due to the species' weight. These branches help support the phasmids weight and allow them to climb effectively.

Proper ventilation is equally important as maintaining high humidity. Ensure ample airflow to prevent stagnant conditions and mould developing. At a minimum, a mesh or netted roof is recommended. Netted material also provides easier grip for the insects, which is especially beneficial during moulting when they often hang from the ceiling.

Breeding giant prickly stick insects is relatively straightforward, as they readily reproduce under suitable conditions once they reach maturity. You may observe males "piggy-backing" on females during mating.

Females typically lay up to a dozen eggs at a time and can produce up to 1000 eggs in their lifetime. They deposit these eggs on the floor of the enclosure with a whip-like movement of their abdomen. The eggs are marbled greyish, brown, and beige in colour, round, and resemble seeds. They have a prominent knob called a capitulum.

Incubation can take anywhere between 5 and 12 months. Maintain the eggs at temperatures similar to those for juveniles and adults, ranging from 20°C to 30°C. Lower temperatures will extend the incubation period. To prevent dehydration, keep the eggs moist. Ensure they receive daily light exposure and regularly check for mould growth.

If you notice mould on an egg, carefully remove it from the container. You can attempt to gently wipe off the mould using a clean paper towel or soft brush. However, if the mould growth is extensive, it's best to discard the egg to protect the health of the others. If mould has developed, thoroughly clean the container housing the eggs. Pay particular attention to the substrate, especially if using paper towels. Vermiculite or coconut fibre substrates are less prone to mould growth.

In the absence of males, female giant prickly stick insects can reproduce via parthenogenesis. This process produces unfertilised eggs that hatch into genetic clones of the female. Unfertilised eggs may take longer to hatch, up to 9 months.