~ Extatosoma Tiaratum (Macleay's spectre / Giant Prickly Stick Insect) Care Sheet ~
Written by S J Clements, 2010. All photos taken by S J Clements.
Last updated: 25th February 2013
Written by S J Clements, 2010. All photos taken by S J Clements.
Last updated: 25th February 2013
Extatosoma Tiaratum (common names Giant Prickly Stick Insect, Macleay's Spectre) is a large species of stick insect native to Australia.
Adult females are covered with thorn-like spikes for defence and camouflage. They grow to about 8 inches long in the wild but can be considerably smaller in captivity (4 - 6 inches long). Males are usually considerably smaller as adults than the females, and will be about half the size. Males also posses a pair of long, fully functioning wings which females do not. Males also lack the long, thorny spikes that females do.
E. tiaratum vary greatly in colour from browns to a sandy yellow to green (with rarer colour phases such as lichen and silver). The most common colours are browns/beige in captivity, in the wild greens/yellows are more commonly found.
Examples of different housing for stick insects.
Examples of different housing for stick insects.
Extatosoma tiaratum are best kept in a well-ventilated, tall enclosure. You can use a mesh style enclosure, plastic tank, glass tank or even a modified large plastic tub or food container with air holes or mesh added at the top. A good sized home for these stick insects is at least 46cm/18inches tall (you may require extra space or a larger enclosure if you keep several individuals). No extra heating is required as these insects are happy at room temperature (20 - 25 degrees). My favourite type of enclosure is an Exo Terra glass vivarium, with a mesh lid. These kind of enclosures provide a good amount of height as well as excellent ventilation and easy accessibility.
The ova look like tiny seeds, which are a mottled brown, black, cream and white in colour with a nib at the top.
An egg in my hand.
Extatosoma tiaratum ova can take anywhere in-between 4 - 9 months to hatch (though in some cases, can take up to 2 years). Hatching times can vary depending on temperature and moisture. If ova have been laid by a mated female, they should produce mixed sex hatchlings. Ova laid by an un-mated female will hatch all female.
Ova need the correct temperature (20 - 25 degrees, room temperature) and moisture levels in order to develop. Moisture is also needed for the young inside to hatch out, dry conditions can make it difficult for a young insect to wriggle free of the egg case, however too much moisture can result in the ova becoming mouldy and rotting so it is necessary to check the ova for signs of mould (which can be carefully cleaned off with a cotton wool bud or very small paintbrush dipped in water).
Keeping And Hatching Ova
The easiest way to keep ova is in a plastic container (like take-out food containers) with holes pierced into the top or you can use a cricket tub which will already have vent holes. You can also use a jar with mesh attached to the top with an elastic band. The ova can be placed on top of some kitchen tissue, which will cushion them as well as keep moisture, though a small amount of plantation soil will also do (though this type of substrate can become mouldy so you need to keep an eye on it). Moss is also a good alternative to use for the base for the eggs to rest on.
Example of a basic incubator - a plastic food container with small holes drilled into the lid and sides.
It is a good idea to put a label on the container somewhere, which indicates the month & year the ova were laid or if you don't know, the month & year which you acquired them. This way you can keep track of how old the ova are (which can help you estimate when they might hatch).
Use a water mister to moisten the tissue/ova. I check on the ova every day both for signs of life as well as for mould and to check on moisture levels (I do this my putting a finger on the kitchen paper, if its dry I mist the ova, if it still feels a little damp I don't spray). I have read that spraying the ova helps to encourage hatching, though as mentioned above, don't get carried away with spraying them! The paper/soil they are sitting on should only feel damp, not soaking wet.
If necessary, the paper towel/kitchen paper can be replaced. When doing this, you can either carefully pick up the ova, or you can use a small/soft paintbrush to gently roll them onto an area while the paper is replaced.
When the young hatch, they will pull themselves free of the ova case, and will scuttle about the place looking for something to climb up. They resemble little fire ants when they emerge (black body with a red head) and at this stage look completely different to the adult insect but in time they will shed their skin and slowly start to resemble a mini adult.
Males and females can be distinguished from early on as males will appear much smoother, leaner, and will eventually develop noticeable wing buds. The females will seem bulkier and will have little bumps¯ running down the abdomen/tail. Females also develop more prominent spikes on their bodies as they mature.
Hatchlings, Nymphs & Feeding/Basic Care
A nymph that has just hatched from its egg.
A nymph that has just hatched from its egg.
Newly hatched nymphs are very quick, and can easily be lost if not kept an eye on! They are also very good at escaping through small gaps and crevices so they must be kept in a secure enclosure until older. Handling must also be kept to a minimum while nymphs are small as they are delicate, and will shed a leg if they feel threatened or become stuck.
A newly hatched nymph on my hand to show size comparison.
Using a large plastic food container with ventilation holes/a mesh top will do as temporary housing. The young insects will need kitchen towel at the bottom of the enclosure (to collect droppings/keep moisture) as well as food plant for them to climb on and feed upon. Here is a list of leaves that this species will eat:
- Eucalyptus (Gunni is the best type to use)
You can use one type of food plant but it is okay to use more than one type of plant in their enclosure. Some insects will seem fussy and prefer one type of leaf over another, whereas some will happily eat what is given to them. Eucalyptus is the best type of food plant as it is what they eat in the wild; it will also encourage bigger, slightly more colourful adults. The oils in Eucalyptus are also great for the insect's immune system.
NOTE: It is advised to remove as many thorns as you can from food plants like bramble and rose. Although not common, it is possible for an insect to get caught up in the thorns and even impale themselves (which will lead to a slow and painful death). If you dont always have time to remove thorns from plants, check your insects everyday to make sure they have not got stuck/injured. Thorns can easily be removed by clipping them off with a strong pair of scissors.
An adult male enjoying some fresh Eucalyptus leaves.
If Eucalyptus is not easy to obtain, then worry not! They do very well on the other listed plants and are particularly fond of bramble - which is the most commonly used food plant for this species of stick insect being kept as a pet in the UK. It can be found in most places, growing wild. Though be sure to rinse any plants you pick to get rid of any dust/dirt etc. Also check the leaves for other insects or eggs. It is not advised that you pick any types of plants growing by a main road as they could become contaminated by exhaust fumes.
After rinsing the leaves, remove any unhealthy leaves (ones with lots of bite marks or that look tatty/dry). You can also trim branches full of leaves to size so that they fit into the enclosure. If you are feeding food plant to very young nymphs, clipping the edges of leaves to make them easier for the youngsters to eat can encourage feeding. Some people prefer to give young nymphs leaves that have already been nibbled on by slightly older stick insects. Look out for signs of feeding to see how easy the nymphs are finding the plant to eat. Though it can take a couple of days for a newly hatched nymph to settle down and take its first meal.
NOTE: Make sure food plants are not treated with pesticides, as this will kill stick insects like any other insect. Wild grown food plant is not likely to be treated but plants purchased from a florist or garden centre are likely to have been treated, florists more so as most will use a preservative to keep the plant from becoming droopy. If you are unsure - it is better to be safe than sorry.
When it comes to water, just mist the food plant/side of the enclosure (but not the insect itself) every day/every couple of days. Young nymphs sometimes enjoy drinking the water droplets off of the leaves or enclosure wall - though they also get their water through the leaves of the food plants too so don't worry if you don't see them drinking. Never put a water dish into an enclosure as nymphs can drown (they breathe through their skin, so if they become submerged and stuck they will drown).
Male nymph drinking water droplets on the side of the tank.
If you keep the food plant in water the plants will last much longer, but you must take care that the nymphs cant climb through the plant and drop into the water - the best thing to use for the plants is a toothbrush holder (with holes) as you can just stick the plants in before covering the gaps with cotton wool without the worry of nymphs slipping in and getting trapped or drowning.
A female nymph drinking water droplets from a leaf.
It is advised that you clean out the enclosure at least once a week (replace old kitchen towel/remove droppings, replace any old/dry food plant, give food plant clean water etc). Larger enclosures can be left for slightly longer (2 weeks max) as long as the food plant is changed as soon as it becomes dry/old or is fully eaten. Keep an eye on the bottom of the enclosure; especially as the weather warms up as the droppings can encourage mould growth. Eggs dropped by adult females can be killed off by mould so must be removed if mould is spotted!
Nymphs to Adults & Shedding Skin (moulting).
As nymphs get bigger, they shed their skin (each shed is known as an instar¯ stage). They do this every month or so on average. Males shed 5 times, whereas females will shed 6 times. Males and females take on completely different appearances when fully grown - females are big and bulky, with a thick abdomen and lots of spikes, and short antenna. Males are smaller, long and slender with long antenna and a pair of long functional wings (females have tiny wings which are too small for flight).
Male nymph after shedding his skin, which is left hanging on a branch next to him.
There is not much indication when an insect is about to shed, but sometimes you can pick up on their body language and guess when a shedding is going to happen soon. My males nymphs would become restless a few hours before shedding and climb about/seem much more active than normal. My female nymph was the opposite however, and just sat in the same spot for a few days; she went off of her food too, and didn't eat anything for about 3 days - it was only the next morning that I noticed she was slightly bigger and that there were tiny pieces of her old skin on the floor (the old skin had been eaten). She slowly went back to normal routine afterwards.
A male has just shed his skin for the final time and has become an adult. The tiny wing buds expand into fully formed wings over about half an hour.
When shedding, a stick insect will usually climb up high, and then hang upside down as the old skin splits at the back. They slide out through the old skin (usually hanging by the abdomen/tail for a while as they dry out and gather strength), and then grab onto a branch or the old skin - they will then hang there for a few hours while the new skin hardens and dries out (they are quite delicate at this stage so must not be disturbed). You may be surprised how a considerably larger insect emerges from the smaller old skin.
It is quite common for the insect to eat the old skin as a first meal. Though make sure to leave a freshly shed insect alone to recover for at least a few hours as it needs its new skin to dry. The insect will also be exhausted from its moult and will need to rest.
If a nymph has lost a limb, it will usually regenerate it when shedding! Though only nymphs that can still shed can do this, adults cannot regenerate lost limbs. Antenna cannot be regenerated - if a full antenna has been lost, it is not uncommon for the insect to regrow a tiny leg on its head in place of the missing antenna!
A regenerated limb is darker in colour and slightly shorter/thinner than the original limbs. This male nymph has regenerated one of his missing back legs after a moult.
NOTE: An insect will not always have the common sense to climb high enough to complete a moult. When this happens the insect will mistakenly start to moult close to the ground and will often slide out onto its back. Most of the time the insect will be able to correct its position unassisted but if you suspect the insect is struggling or is unable to moult properly, then it is advised to help by lifting the branch higher/moving whatever the insect it holding onto. In some cases (like if the insect falls during a moult) you can help by picking it up and either hooking part of the old skin onto a branch or by holding part of the old skin until the insect has finished its moult (see photo below). A bad moult can result in deformations in the new skin or in the worse cases; death.
A Giant spiny nymph required help to moult. I allowed it to shed most of the skin in my hand before hooking the old skin onto some bramble.
You may also notice that as nymphs get older and shed, they slow down considerably and will seem more laid back. Females are especially happy to sit in the same spot for hours, and sometimes days on end! Males and females seem to be more active at night (as in the wild it is safer to move around at this time) but you will see them move around and feed during the day too.
I mentioned above that the males grow fully functioning wings on their final moult into an adult. This is nothing to worry about as the wings are mostly there for escaping predators and searching for females. They rarely use the wings and are more likely to do so if they are frightened by something. I personally have owned several adult males and not one of them ever attempted to fly, even when being handled. They aren't great flyers and are more likely to fall with style than do a proper, fully coordinated flight!
Males can secrete a defensive fluid from the end of their abdomen/tail if they are intimidated. This fluid is harmless to humans and smells a bit like toffee!
Size difference between adult male/female.
Adult females are quite impressive in size when fully matured. They are noticeably bigger than males and will start to lay eggs a few weeks after their final moult to an adult. The female can lay eggs that may hatch even if she hasn't mated through a process called parthenogenesis¯ (a form of asexual reproduction found in females, where growth and development of embryos occurs without fertilization by a male).
This female has just finished her final moult into an adult; as you can see she needs plenty of space!
The average lifespan of Extatosoma tiaratum is 6 - 9 months for males, and 9 - 18 months for females.
Health & Illness
Stick insects are generally very healthy. Young insects (hatchlings) are very sensitive and can sometimes unexpectedly die for no apparent reason. Captive bred insects have no problems from predators or parasites.
A lack of fresh food plant, moisture or too cold a temperature can have effects on a stick insect - cold environments will make them lethargic and they could potentially become unwell from lack of energy to feed. Too much moisture in an enclosure can result in mould growth in the enclosure, which can harm the insect. Old/dry food plant can potentially make an insect ill from being unable to properly digest it. Young Bramble leaves, that are light in colour/small can also be a problem as they contain toxins. If feeding Bramble to nymphs or adults it is best to use the darker green "adult" leaves.
Pesticides can cause a swift death for stick insects. Pesticide poisoning symptoms are: uncontrollable motor function, lack of coordination, suddenly dropping from a branch and not being able to get up.
NOTE: How can you tell if a stick insect has passed away? A lot of stick insects, especially the Indian stick insect can "play dead" by dropping down onto the floor and pulling their legs in. A stick insect that has died will not exhibit this behaviour and will simply fall to the ground with its legs bent slightly inwards/sprawled out. It will not respond to any touch and will go limb when picked up. Another sign of death is that you will notice the insect will not move from the same spot for several days. If you are unsure if your insect has passed away, pick it up and put it into a temporary enclosure (like a clear box with vent holes). Movement later in the day will indicate if your insect is still alive.
Extatosoma tiaratum are generally friendly, and are an easy exotic species to keep. They will happily climb onto your hand if you are gentle with them, and will not hesitate to explore and try to climb to the highest point they can! Picking them up directly is not advised (as it can cause stress), and care must be taken when transferring an insect from a branch, as nymphs are known to shed a leg if they feel threatened. It is not advised to disturb an insect if it is feeding.
An adult male sitting on my hand.
These insects are harmless to humans, they have no sting (even though they sometimes look a bit like scorpions when they curl their abdomen/tail), bite or poison. The only self-defence they have is:
- Males have wings, which they can use to make a quick escape from predators. However they aren't very good fliers and will usually drop down after a few feet.
- Females have spikes on their body and abdomen, which discourages predators from eating them: therefore they must be handled gently.
- Males can secrete a fluid from the end of their abdomen to discourage predators eating them. This fluid is harmless to people and smells like peanut butter/toffee!
- Males and females are capable of doing a hand stand¯ and spreading out their back legs. If a predator touches the abdomen, the insect will pinch the target by slamming its legs together. They only do this if they feel really threatened, but this action is more likely to surprise a human than do any harm.
- Swaying from side to side, to simulate being a leaf on a tree in the wind.
- Curling the abdomen (tail), which resembles a scorpion getting ready to strike.
If you need to move an insect to clean out the enclosure or change food plants and it isn't responding to your hand/a stick being offered to climb on, you can get the insect to move by blowing on it (simulating the wind), this usually encourages the insect to move. If still no response, a gentle touch to the leg or side of the body usually works.
An adult female on my arm.
If all of the above fails, moving the food plant with the insect on is the easiest solution, as the insect is then easier to move onto the enclosure wall or onto another plant/stick. Cleaning out the enclosure is easier in the morning/durring the day when the insects will be more sleepy/inactive.
Male nymph reaching up after noticing the tank lid being opened!
When it comes to putting the insect back, they will generally climb onto the enclosure wall themselves when they are close enough (as they have the instinct to climb up). If you need to lower them in, use a stick - get the insect to walk onto it, then lower it into the enclosure and gently let go once it is secure.
These insects will sometimes respond to your presence near the enclosure by reaching up. Sometimes you can even hand feed your stick insect by offering it a leaf while it is sitting on your hand.
Female nymph on my hand. Females tend to be less active than males.
Keeping More Than One:
Extatosoma tiaratum do not depend on others to keep them company, and can happily live on their own. However if you wish to keep several in one enclosure you need to make sure over crowding isn't an issue; for example they need enough space for shedding (if there are too many together, the shedding insect can be disturbed or even knocked off of its perch). Keeping too many nymphs together in a small space can result in them nibbling each other's legs by mistake and insects shedding limbs from stress