Extatosoma tiaratum

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Extatosoma tiaratum
Australian Walking Stick.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Phasmatodea
Family: Phasmatidae
Subfamily: Extatosomatinae
Genus: Extatosoma
Species:
E. tiaratum
Binomial name
Extatosoma tiaratum
(Macleay, 1826)

Extatosoma tiaratum, commonly known as the spiny leaf insect, the giant prickly stick insect, [2] Macleay's spectre, [3] or the Australian walking stick, is a large species of Australian stick insect. [4] [5] The species has the Phasmid Study Group number PSG9. [6]

Contents

Range

E. tiaratum is endemic to rainforests in Australia, with most of its range in eastern New South Wales and eastern Queensland, but it is also found in eastern Victoria (one old record) and South Australia (possibly introduced). [1] [7] The closely related and similar E. popa is from New Guinea. [8]

Description

Male E. tiaratum in fifth instar Extatosoma tiaratum 114.jpg
Male E. tiaratum in fifth instar
Male E. tiaratum Male Extatosoma tiaratum (16615999493).jpg
Male E.tiaratum

Female adult E. tiaratum are covered with thorn-like spikes for defense and camouflage. Their long, rounded bodies grow to about 20 cm (8 in) long. [4] [5] The females are further described as "heavy-bodied, brachypterous and having numerous spines and integumental expansions on the face and legs, including a tuft of spines on the conical occiput of the hypognathous head". [9] As mentioned, the wings of the female are too small for flying, especially when she is gravid. [2]

Exhibiting the sexual dimorphism of many similar insects (particularly other phasmids as well as mantises), males are small and thinner, growing only about 11 cm (4.5 in) in length and have three ocelli. Males lack the thorny growths except for spikes around their faces. They have long wings and are good flyers who readily take to the air if disturbed or in search of females. [4] [10]

Anti-predator adaptations

Threat behaviour

Both sexes, when threatened, adopt a threat pose, standing on the front and middle legs, pointing their abdomen up or to the side in a sort of "scorpion" pose. They fold back their legs to defend themselves if anything comes in contact with their abdomen; the pincer movement with the sharp spines on the rear legs can puncture human skin. Adults make clicking sounds and can release a defensive odor reminiscent of toffee. Males may attempt to startle predators by flashing their wings open. [4] [11]

Camouflage

E. tiaratum makes use of both passive and active camouflage. It adopts a curved pose when it hangs inverted amongst foliage with "its highly procryptic abdomen curled over its back." [3] Individual E. tiaratum vary in color and appear brown, mottled brown, green, reddish, cream, yellowish, or entirely white. [3] [9]

Like many stick insects, E. tiaratum actively sways back and forth or side to side when disturbed or when there is a gust of wind, with a frequency distribution like foliage rustling in the wind. The swaying behaviour may be motion crypsis, preventing detection by predators, or motion masquerade, promoting misclassification (as something other than prey), or a combination of the two. [2] [12]

Mimicry

Newly hatched E. tiaratum nymphs are ant mimics and resemble the insects in whose nest they are born. Their aposematic pattern—orange head, white collar, the rest black—mimics the ant genus Leptomyrmex and makes them appear toxic. Although most adult stick insects are notoriously slow, these nymphs are speedy, active, and quickly make their way to the trees. Their locomotion slows when they moult into their second and subsequent instars. Females acquire their distinctive spiky appearance through additional moults. [2] [4] [9]

Reproduction

E. tiaratum nymph in its first instar Extatosoma.tiaratum.1st.instar.lateral.view.jpg
E. tiaratum nymph in its first instar
E. tiaratum at the Frankfurt Zoological Garden Australische Gespenstschrecke (fcm).jpg
E. tiaratum at the Frankfurt Zoological Garden

E. tiaratum typically reproduce through sexual reproduction and produce eggs that hatch four months later. When no males are present in the population, this stick insect exhibits parthenogenesis instead. Eggs laid without fertilization take up to nine months to hatch and produce only females. In either cases, the female "flicks" her eggs, swinging her tail, up to several feet to land on the forest floor. These eggs must be kept relatively cool - under 25 °C - or they are unlikely to hatch. [3] [4]

The outside material of E. tiaratum eggs consists of lipids and other organic compounds that ants identify as food. They carry these eggs to their colony, consume the edible outer portion, and dump the intact eggs into their waste piles. Luckily for captive breeding, the ants eating the edible outer layer is not crucial to development, so they will hatch just as healthy without the need for any removal of the outer layer, which is not easily visible. [4] [9]

An E. tiaratum crawling out of its old skin Extatosoma tiaratum - Crawling out of skin.jpg
An E. tiaratum crawling out of its old skin
E. tiaratum eggs Extatosoma tiaratum-eggs.jpg
E. tiaratum eggs

Cultivation

Close-up image of E. tiaratum Dinner time for Kati (Extatosoma tiaratum).png
Close-up image of E. tiaratum
Plate 8 from "The Monograph of the Genus Phasma" by George Robert Gray Gray plate8.jpeg
Plate 8 from "The Monograph of the Genus Phasma" by George Robert Gray

This species is relatively common in captivity. It is used in laboratories, kept for projects in schools (as is Carausius morosus [2] ), and is a popular pet among breeders of exotic insects in North America and Europe. One breeder advises specifically "For a stick insect with body length 127mm, to keep 2 adult females, you need a cage at least 600mm high, 300mm deep and 300mm wide." [3]

Although the gestation period of their eggs is several months long, they are prolific breeders. A breeder notes that because of this insect's habit of flicking its eggs, one can "hear them clicking against the glass" of their terraria. [3] Some breeders in the United Kingdom, concerned with the negative effects of inbreeding on the vitality of their stock, have introduced new genes from abroad. [2]

Females live to about 18 months old, males to only 6–8 months. [13]

Diet

E. tiaratum are herbivores and although they thrive on Eucalyptus which is their native food, breeders abroad recommend feeding them bayberry, bramble, hawthorn, hazel, oak, photinia, raspberry, rose, and salmon berry (red or yellow) and guava. [3] [14]

[4] Although they survive well on non-eucalypt leaves, they don't always grow as large or retain the same natural colour. [13]

Defense

E. tiaratum are incapable of bites and stings and rely solely on passive defense and camouflage.[ citation needed ] Some predators (such as mantids) have good vision, and can see the most camouflaged animals. When threatened, spiny leaf insects assume an aggressive posture such as rearing up. Females have a tough, spiky exoskeleton while males are winged and can fly away from danger. All adults have glands under that spray a colorless toffee-like odor which is pleasant to humans, but deters most predators. [15] [16]

Mating E. tiaratum Phasmatidae Extatosoma tiaratum 2.jpg
Mating E. tiaratum

Related Research Articles

<span class="mw-page-title-main">Phasmatodea</span> Order of stick and leaf insects

The Phasmatodea are an order of insects whose members are variously known as stick insects, stick-bugs, walkingsticks, stick animals, or bug sticks. They are also occasionally referred to as Devil's darning needles, although this name is shared by both dragonflies and crane flies. They can be generally referred to as phasmatodeans, phasmids, or ghost insects, with phasmids in the family Phylliidae called leaf insects, leaf-bugs, walking leaves, or bug leaves. The group's name is derived from the Ancient Greek φάσμα phasma, meaning an apparition or phantom, referring to their resemblance to vegetation while in fact being animals. Their natural camouflage makes them difficult for predators to detect; still, many species have one of several secondary lines of defense in the form of startle displays, spines or toxic secretions. Stick insects from the genera Phryganistria, Ctenomorpha, and Phobaeticus include the world's longest insects.

<span class="mw-page-title-main">Ant mimicry</span> Animals that resemble ants

Ant mimicry or myrmecomorphy is mimicry of ants by other organisms; it has evolved over 70 times. Ants are abundant all over the world, and potential predators that rely on vision to identify their prey, such as birds and wasps, normally avoid them, because they are either unpalatable or aggressive. Some arthropods mimic ants to escape predation, while some predators of ants, especially spiders, mimic them anatomically and behaviourally in aggressive mimicry. Ant mimicry has existed almost as long as ants themselves; the earliest ant mimics in the fossil record appear in the mid-Cretaceous alongside the earliest ants.

<i>Carausius morosus</i> Species of insect

Carausius morosus is a species of Phasmatodea (phasmid) often kept as pets by schools and individuals. Culture stocks originate from a collection from Tamil Nadu, India. Like the majority of the Phasmatodea, C. morosus are nocturnal. Culture stocks are parthenogenetic females that can reproduce without mating. There are no reports of males, although in captivity, gynandromorphs are sometimes reared.

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<i>Acrophylla titan</i> Species of stick insect

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<i>Eurycnema goliath</i> Species of stick insect

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<i>Anchiale austrotessulata</i> Species of insect

Anchiale austrotessulata, the tessellated stick insect, tessellated phasmid or tessulata stick insect, is a medium-sized, stick insect found in the Brisbane area of Australia. Fully grown males in mating season exhibit frenetic behaviour. This species is also parthenogenetic.

<i>Ctenomorpha marginipennis</i> Species of stick insect

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<i>Pulchriphyllium giganteum</i> Species of leaf insect

Pulchriphyllium giganteum, commonly known as the Giant Malaysian Leaf insect, is a species of leaf insects described from Malaysia by Hausleithner in 1984 and placed in the genus Pulchriphyllium since 2021. Pulchriphyllium giganteum is the largest species belonging to the genus Pulchriphyllium reaching 105 mm in size. They are found most abundantly in the west Malaysian tropics. The females typically have large elytra that lie edge to edge on the abdomen and tend to lack hind wings making them usually flightless. Males have small elytra and sometimes transparent non-leaflike functional hind wings. Pulchriphyllium giganteum found in the wild tend to be mostly females and the first male of this species was not found until 1994. In captivity, the species has primarily been observed to reproduce through parthenogenesis meaning the females are asexual. The primary reproductive pattern in the wild is unknown. Eggs tend to be brown or black and glossy and resemble seeds. They hatch around 6 months after breeding. Newly hatched young nymphs tend to be wingless and brown or reddish in color. They develop their green color after feeding on leaves. Both the adult and larval stages are phytophagous meaning they feed on plants. The main plant food sources for this species are oak and bramble tree leaves.

<i>Pulchriphyllium bioculatum</i> Species of leaf insect

Pulchriphyllium bioculatum, Seychelles leaf insect, Javanese leaf insect, or Gray's leaf insect, is a leaf insect of the family Phylliidae native to tropical Asia as well as Madagascar, Mauritius and the Seychelles. It was first described by George Robert Gray in 1832 and was the first phasmid he discovered. Leaf insects have extremely flattened, irregularly shaped bodies, wings, and legs. They are usually about 5–10 cm long. They are called leaf insects because their large, leathery forewings have veins that look similar to the veins on the particular type of leaves they inhabit. Its scientific name bioculatum means "two-eyed" and refers to the two dots located on the abdomen just in this species.

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<i>Haaniella dehaanii</i> Species of stick insect

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References

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  2. 1 2 3 4 5 6 "Extatosoma tiaratum tiaratum* (Macleay, 1827), "Macleay's Spectre/ Giant Prickly Stick Insect"". Archived from the original on 2007-07-08. Retrieved 2018-09-21.
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  4. 1 2 3 4 5 6 7 8 "Giant Prickly Leaf Bug (Extatosoma tiaratum) (PSG-9)". PhasmidsinCyberspace.com. 2005. Archived from the original on 2015-09-24.
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  8. "species Extatosoma popa Stål, 1875". phasmida.speciesfile.org. Retrieved 8 August 2023.
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  11. Brock, Paul D.; Hasenpusch, Jack W. (2009). The Complete Field Guide to Stick and Leaf Insects of Australia. Csiro Publishing. pp. 126–128. ISBN   978-0-643-09418-5.
  12. Bian, Xue; Elgar, Mark A.; Peters, Richard A. (2016). "The swaying behavior of Extatosoma tiaratum : motion camouflage in a stick insect?". Behavioral Ecology. 27 (1): 83–92. doi: 10.1093/beheco/arv125 .
  13. 1 2 "Spiny Leaf Insects". ABC. Archived from the original on 2016-03-29. Retrieved 2018-09-21.
  14. Supply, Reptile (2021-09-13). "How to Care for Your Giant Prickly Stick Insect". ReptileSupply.com. Retrieved 2022-08-04.
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