Editing Phasmatodea

{{short description|Order of stick and leaf insects}}
{{redirect-distinguish|Stick insect|Stick grasshopper|Stick mantis|Water stick insect}}
{{Use dmy dates|date=September 2020}}
{{automatic taxobox
| fossil_range = {{fossilrange|Jurassic|Recent}}
| image = Le Caylar fg01.JPG
| image_caption = ''[[Pijnackeria hispanica]]''
| taxon = Phasmatodea
| authority = [[Georgij Georgiewitsch Jacobson|Jacobson]] & [[Valentin Lvovich Bianchi|Bianchi]], 1902
| display_parents = 4
| subdivision_ranks = Subgroups
| subdivision = {{extinct}}[[Susumanioidea]]<br />
[[Timematodea]]<br />
[[Euphasmatodea]] (=Verophasmatodea)
}}
[[File:Pitcher plant and Stick insect.JPG|thumb|upright|Phasmid in marginal forest on a [[pitcher plant]] in the [[Philippines]]]]
The '''Phasmatodea''' (also known as '''Phasmida''' or '''Phasmatoptera''') are an [[Order (biology)|order]] of [[insect]]s 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 [[Dragonfly|dragonflies]] and [[Tipuloidea|crane flies.]]<ref>{{Cite book |first=Vance |last=Randolph |url=http://worldcat.org/oclc/868269974 |title=Ozark Magic and Folklore. |date=2012 |publisher=Dover Publications |isbn=978-1-306-33958-2 |oclc=868269974}}</ref> 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]] {{lang|grc|φάσμα}} ''{{transliteration|grc|phasma}}'', meaning an [[Apparitional experience|apparition]] or [[Ghost|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 [[antipredator adaptation|lines of defense]] in the form of [[startle display]]s, spines or toxic secretions. Stick insects from the genera ''[[Phryganistria]]'', ''[[Ctenomorpha]]'', and ''[[Phobaeticus]]'' include the world's longest insects.

Members of the order are found on all continents except [[Antarctica]], but they are most abundant in the [[tropics]] and [[subtropics]]. They are herbivorous, with many species living unobtrusively in the tree canopy. They have an [[incomplete metamorphosis]] life cycle with three stages: egg, [[Nymph (biology)|nymph]] and adult. Many phasmids are [[parthenogenic]] or [[Androgenesis|androgenetic]], and do not require fertilized eggs for female offspring to be produced. In hotter climates, they may breed all year round; in more temperate regions, the females lay eggs in the autumn before dying, and the new generation hatches in the spring. Some species have wings and can disperse by flying, while others are more restricted.

==Description==
[[File:Giant Stick Insect (Phobaeticus serratipes) on Sylvain (8727651923).jpg|thumb|left|''[[Phobaeticus serratipes]]'']]
[[File:Phobaeticus chani Bragg, 2008; Holotype Female dorsal view.jpg|thumb|left|upright=1.5<!--width for very low image-->|Female ''[[Phobaeticus chani]]'', the world's second-longest insect. This species grows to a total length of {{cvt|56.7|cm}} (front legs fully extended) and body length of {{cvt|35.7|cm}}.<ref>{{cite web|url= http://www.nhm.ac.uk/about-us/news/2008/october/worlds-longest-insect-revealed.html|title= World's longest insect revealed|access-date= 2008-10-16|publisher= [[Natural History Museum, London|Natural History Museum]]|date= 2008-10-16|url-status= dead|archive-url= https://web.archive.org/web/20081019104055/http://www.nhm.ac.uk/about-us/news/2008/october/worlds-longest-insect-revealed.html|archive-date= 2008-10-19}}</ref>]]

Phasmids vary greatly in size, with females typically growing larger than males of the same species.<ref>{{cite book | last1=Bradler | first1=S. | last2=Buckley | first2=T.R. | year=2018 | title=Insect Biodiversity: Science and Society | chapter=Biodiversity of Phasmatodea | pages=281–313 | volume=II | editor=Foottit, R.G. | editor2=Adler, P.H. | publisher=John Wiley & Sons Ltd | doi=10.1002/9781118945582.ch11 | isbn=978-1-118-94557-5 }}</ref> Males of the smallest species, such as ''[[Timema cristinae]]'', reach about {{convert|2|cm|in|1}} long,<ref>{{Cite journal|last=Vickery|first=V.R.|date=1993|title=Revision of ''Timema'' Scudder (Phasmatoptera: Timematodea) including three new species|journal=The Canadian Entomologist|volume=125|issue=4|pages=657–692|doi=10.4039/ent125657-4|s2cid=86710665 |issn=0008-347X}}</ref> while females of the longest, an [[undescribed species]] informally known as ''[[Phryganistria chinensis|Phryganistria "chinensis"]]'', can be up to {{convert|64|cm|in}} in total length, including outstretched legs. This makes it the [[List of largest insects#Stick insects (Phasmatodea)|world's longest insect]].<ref>{{Cite web|url=https://www.iflscience.com/plants-and-animals/worlds-new-longest-insect-is-the-length-of-your-arm/|title=World's New Longest Insect Is The Length Of Your Arm|last=Hale|first=Tom|date=14 August 2017|website=IFLScience|language=en|access-date=2020-03-27}}</ref> The heaviest species of phasmid is likely to be ''[[Heteropteryx dilatata]]'', the females of which may weigh as much as {{convert|65|g|oz|1|abbr=on}}.<ref>{{cite web|title=Phasmids: An Introduction to the Stick Insects and Leaf Insects|url=http://phasmid-study-group.org/content/Phasmids-Introduction-Stick-Insects-and-Leaf-Insects|access-date=22 March 2011}}</ref>

Some phasmids have cylindrical stick-like shapes, while others have flattened, leaflike shapes. Many species are wingless, or have reduced wings.<ref name=IIBD>{{cite book |author1=Hoell, H.V. |author2=Doyen, J.T. |author3=Purcell, A.H. |year=1998 |title=Introduction to Insect Biology and Diversity |edition=2nd |publisher= Oxford University Press |pages= 398–399|isbn= 978-0-19-510033-4}}</ref> The [[Thorax (insect anatomy)|thorax]] is long in the winged species, since it houses the flight muscles, and is typically much shorter in the wingless forms. Where present, the first pair of wings is narrow and [[Keratin|cornified]] (hardened), while the hind wings are broad, with straight veins along their length and multiple cross-veins. Their wing [[Insect wing#Venation|venation]] is unique among insects.<ref>[https://hal.archives-ouvertes.fr/hal-02349207/document To be or not to be: postcubital vein in insects revealed by microtomography]</ref> The body is often further modified to resemble vegetation, with ridges resembling leaf veins, bark-like [[tubercles]], and other forms of [[camouflage]]. A few species, such as ''[[Carausius morosus]]'', are even able to change their [[Biological pigments|pigmentation]] to match their surroundings. The [[Insect mouthparts|mouthparts]] project out from the head. Chewing [[Mandible (insect mouthpart)|mandibles]] are uniform across species. The legs are typically long and slender, and some species are capable of limb [[autotomy]] (appendage shedding).<ref name=IIBD/> Phasmids have long, slender [[Antenna (biology)|antennae]], as long as or longer than the rest of the body in some species.

[[File:Australian Leaf Insect, portrait.jpg|thumb|left|Head of a female ''[[Extatosoma tiaratum]]'']]
All phasmids possess [[compound eye]]s, but [[Simple eye in invertebrates#Dorsal ocelli|ocelli]] (light-sensitive organs) are only known from the five groups Lanceocercata, Necrosciinae, Pseudophasmatidae, Palophidae and Phylliidae. Of these only the first three groups have females with ocelli, which like the wings seems to have re-evolved from ancestors that had lost them.<ref>[https://bmcecolevol.biomedcentral.com/articles/10.1186/s12862-022-02018-5 A second view on the evolution of flight in stick and leaf insects (Phasmatodea)]</ref> Phasmids have an impressive visual system that allows them to perceive significant detail even in dim conditions, which suits their typically [[nocturnal]] lifestyle. They are born equipped with tiny compound eyes with a limited number of facets. As phasmids grow through successive [[moulting|molts]], the number of facets in each eye is increased along with the number of [[photoreceptor cell]]s. The sensitivity of the adult eye is at least tenfold that of the nymph in its first [[instar]] (developmental stage). As the eye grows more complex, the mechanisms to adapt to dark/light changes are also enhanced: eyes in dark conditions evidence fewer screening pigments, which would block light, than during the daytime, and changes in the width of the retinal layer to adapt to changes in available light are significantly more pronounced in adults. The larger size of the adult insects' eyes makes them more prone to radiation damage. This explains why fully grown individuals are mostly nocturnal. Lessened sensitivity to light in the newly emerged insects helps them to escape from the [[leaf litter]] wherein they are hatched and move upward into the more brightly illuminated foliage. Young stick insects are [[Diurnality|diurnal]] (daytime) feeders and move around freely, expanding their [[foraging]] range.<ref>{{cite journal |last=Meyer-Rochow |first=V. Benno |author2=Essi Keskinen |title=Post-embryonic photoreceptor development and dark/light adaptation in the stick insect Carausius morosus (Phasmida, Phasmatidae) |journal=Applied Entomology and Zoology |year=2003 |volume=38 |issue=3 |pages=281–291 |doi=10.1303/aez.2003.281|doi-access=free|bibcode=2003AppEZ..38..281M }}</ref>

Stick insects have two types of pads on their legs: sticky "toe pads" and non-stick "heel pads" a little further up their legs. The heel pads are covered in microscopic hairs which create strong friction at low pressure, enabling them to grip without having to be peeled energetically from the surface at each step. The sticky toe pads are used to provide additional grip when climbing but are not used on a level surface.<ref>{{cite web |title=How stick insects honed friction to grip without sticking |url=http://phys.org/news/2014-02-insects-honed-friction.html |publisher=Phys.org |access-date=3 October 2015 |date=19 February 2014}}</ref>

==Distribution==

Phasmatodea can be found all over the world except for the Antarctic and Patagonia. They are most numerous in the [[tropics]] and [[subtropics]]. The greatest diversity is found in [[Southeast Asia]] and [[South America]], followed by [[List of Phasmatodea of Australia|Australia]], Central America, and the southern United States.<ref>{{cite web |title=Distribution for order Phasmida |url=http://phasmida.speciesfile.org/Common/editTaxon/Distribution/ShowDistribution.aspx?TaxonNameID=1199226 |access-date=2 October 2015}}</ref> Over 300 species are known from the island of [[Borneo]], making it the richest place in the world for Phasmatodea.<ref>{{cite book|last1=Bragg|first1=Philip E.|title=Phasmids of Borneo|date=2001|publisher=Kota Kinabalu|isbn=978-983-812-027-2}}</ref>

==Anti-predator adaptations==
[[File:Dares ulula Pärchen.jpg|thumb |upright |A pair of camouflaged ''[[Dares ulula]]'']]
{{further |Anti-predator adaptations |Camouflage |Deimatic behaviour}}

Phasmatodea species exhibit mechanisms for defense from [[predators]] that prevent an attack from happening in the first place (primary defense), and defenses that are deployed after an attack has been initiated (secondary defense).<ref name=Matthews>{{cite book|author1=Matthews, Robert W.|author2=Matthews, Janice R. |title=Insect Behavior |url=https://books.google.com/books?id=HVz2Wztita8C&pg=PA187 |year=2009 |publisher=Springer Science & Business Media |isbn=978-90-481-2389-6 |pages=187–189}}</ref>

The defense mechanism most readily identifiable with Phasmatodea is [[camouflage]], in the form of a plant [[mimicry]]. Most phasmids are known for effectively replicating the forms of sticks and leaves, and the bodies of some species (such as ''[[Pseudodiacantha macklotti]]'' and ''[[Bactrododema centaurum]]'') are covered in mossy or [[lichen]]ous outgrowths that supplement their disguise. Remaining absolutely stationary enhances their inconspicuousness.<ref name=Matthews/> Some species have the ability to change color as their surroundings shift (''[[Bostra scabrinota]]'', ''[[Timema californica]]''). In a further behavioral adaptation to supplement [[crypsis]], a number of species perform a rocking motion where the body is swayed from side to side; this is thought to mimic the movement of leaves or twigs swaying in the breeze.<ref name="bedford" /><ref>{{Cite journal|last1=Bian|first1=Xue|last2=Elgar|first2=Mark A.|last3=Peters|first3=Richard A.|date=2016-01-01|title=The swaying behavior of Extatosoma tiaratum: motion camouflage in a stick insect?|journal=Behavioral Ecology|language=en|volume=27|issue=1|pages=83–92|doi=10.1093/beheco/arv125|issn=1045-2249|doi-access=free}}</ref> Another method by which stick insects avoid predation and resemble twigs is by entering a [[cataleptic state]], where the insect adopts a rigid, motionless posture that can be maintained for a long period.<ref name=RobinsonEMM/> The nocturnal feeding habits of adults also help Phasmatodea to remain concealed from predators.<ref name=RobinsonEMM>{{cite journal |author=Robinson, Michael H. |year=1968 |title=The defensive behaviour of the Javanese stick insect, ''Orxines macklotti'' De Haan, with a note on the startle display of ''Metriotes diocles'' (Westw.)(Phasmatodea, Phasmidae) |journal=Entomologist's Monthly Magazine |volume=104 |pages=46–54}}</ref>

[[File:Flügel Peruphasma schultei.jpg|thumb |right |Hindwing [[Deimatic display|deimatic (startle) display]] of a male ''[[Peruphasma schultei]]'']]
[[File:Haaniella dehaanii-subadult threaten female.JPG|thumb |left |Defensive pose of a subadult female ''[[Haaniella dehaanii]]'']]

In a seemingly different method of defense, many species of Phasmatodea seek to [[deimatic behaviour|startle]] the encroaching predator by flashing bright colors that are normally hidden, and making a loud noise.<ref name=Robinson/> When disturbed on a branch or foliage, some species, while dropping to the undergrowth to escape, will open their wings momentarily during free fall to display bright colors that disappear when the insect lands. Others will maintain their display for up to 20 minutes, hoping to frighten the predator and convey the appearance of a larger size. Some, such as ''[[Pterinoxylus spinulosus]]'', accompany the visual display with the noise made by rubbing together parts of the wings.<ref name=Robinson>{{cite journal |author=Robinson, Michael H. |year=1968 |title=The defensive behavior of ''Pterinoxylus spinulosus'' Redtenbacher, a winged stick insect from Panama (Phasmatodea) |journal=Psyche: A Journal of Entomology |volume=75 |issue=3 |pages=195–207 |doi=10.1155/1968/19150 |doi-access=free}}</ref>

Some species, such as the young nymphs of ''[[Extatosoma tiaratum]]'', have been observed to curl the [[Abdomen#Invertebrates|abdomen]] upwards over the body and head to resemble ants or scorpions in an act of [[mimicry]], another defense mechanism by which the insects avoid becoming prey. The eggs of some species such as ''[[Diapheromera femorata]]'' have fleshy projections resembling [[elaiosome]]s (fleshy structures sometimes attached to seeds) that attract ants. When the egg has been carried to the colony, the adult ant feeds the elaiosome to a larva while the phasmid egg is left to develop in the recesses of the nest in a protected environment.<ref>{{cite web |url=http://animaldiversity.org/accounts/Diapheromera_femorata/ |title=''Diapheromera femorata'': Common American Walkingstick |author1=Harrington, Lindsay |author2=Sannino, Dave |year=2011 |work=Animal Diversity Web |publisher=University of Michigan |access-date=7 October 2015}}</ref>

When threatened, some phasmids that are equipped with [[Femur#Variation|femoral]] spines on the [[metathorax|metathoracic]] legs (''[[Oncotophasma martini]]'', ''[[Eurycantha calcarata]]'', ''[[Eurycantha horrida]]'', ''[[Diapheromera veliei]]'', ''[[Diapheromera covilleae]],'' ''[[Heteropteryx dilatata]]'') respond by curling the abdomen upward and repeatedly swinging the legs together, grasping at the threat. If the menace is caught, the spines can, in humans, draw blood and inflict considerable pain.<ref name="bedford">{{cite journal |last=Bedford |first=Geoffrey O. |title=Biology and Ecology of the Phasmatodea |journal=Annual Review of Entomology |year=1978 |volume=23 |pages=125–149 |doi=10.1146/annurev.en.23.010178.001013}}</ref>

Some species are equipped with a pair of glands at the [[anterior]] (front) edge of the [[prothorax]] that enables the insect to release defensive secretions, including chemical compounds of varying effect: some produce distinct odors, and others can cause a stinging, burning sensation in the eyes and mouth of a predator.<ref>{{cite journal |last=Dossey |first=Aaron |title=Insects and their chemical weaponry: New potential for drug discovery |journal=Natural Product Reports |date=December 2010 |volume=27 |issue=12 |pages=1737–1757 |doi=10.1039/C005319H |pmid=20957283}}</ref> The spray often contains pungent-smelling [[volatility (chemistry)|volatile]] [[metabolite]]s, previously thought to be concentrated in the insect from its plant food sources. However, it now seems more likely that the insect manufactures its own defensive chemicals.<ref name=Dossey2006>{{cite journal |last=Dossey |first=Aaron |author2=Spencer Walse |author3=James R. Rocca |author4=Arthur S. Edison |title=Single-Insect NMR: A New Tool To Probe Chemical Biodiversity |journal=ACS Chemical Biology |date=September 2006 | volume=1 |issue=8 | pages=511–514 | doi=10.1021/cb600318u |pmid=17168538}}</ref> Additionally, the chemistry of the defense spray from at least one species, ''[[Anisomorpha buprestoides]]'', has been shown to vary<ref name=Dossey2006 /> based on the insect's life stage or the particular population it is part of.<ref>{{cite journal |last=Dossey |first=Aaron |author2=Spencer S. Walse |author3=Arthur S. Edison |title=Developmental and Geographical Variation in the Chemical Defense of the Walkingstick Insect Anisomorpha buprestoides |journal=Journal of Chemical Ecology |year=2008 |volume=34 |issue=5 |pages=584–590 |doi=10.1007/s10886-008-9457-8 |pmid=18401661 |bibcode=2008JCEco..34..584D |s2cid=10765114}}</ref> This chemical spray variation also corresponds with regionally specific color forms in populations in Florida, with the different variants having distinct behaviors.<ref>{{cite journal |last=Conle |first=Oskar |author2=Frank H. Hennemann |author3=Aaron T. Dossey |title=Survey of the Color Forms of the Southern Twostriped Walkingstick (Phasmatodea: Areolatae: Pseudophasmatidae: Pseudophasmatinae: Anisomorphini), With Notes on Its Range, Habitats, and Behaviors |journal=Annals of the Entomological Society of America |date=March 2009 |volume=102 |issue=2 |pages=210–232 |doi=10.1603/008.102.0204|doi-access=free}}</ref> The spray from one species, ''[[Megacrania nigrosulfurea]]'', is used as a treatment for skin infections by a tribe in [[Papua New Guinea]] because of its [[antibacterial]] constituents.<ref>{{cite journal | last1 = Prescott | first1 = T. | last2 = Bramham | first2 = J. | last3 = Zompro | first3 = O. | last4 = Maciver | first4 = S.K. | year = 2010 | title = Actinidine and glucose from the defensive secretion of the stick insect ''Megacrania nigrosulfurea'' | journal = Biochemical Systematics and Ecology | volume = 37 | issue = 6| pages = 759–760 | doi=10.1016/j.bse.2009.11.002}}</ref> Some species employ a shorter-range defensive secretion, where individuals bleed reflexively through the joints of their legs and the seams of the [[exoskeleton]] when bothered, allowing the blood ([[hemolymph]]), which contains distasteful compounds, to discourage predators. Another ploy is to regurgitate their stomach contents when harassed, repelling potential predators.<ref name=Costa>{{cite book |author=Costa, James T. |title=The Other Insect Societies |url=https://books.google.com/books?id=PYRFDrZs9QAC&pg=PA141 |year=2006 |publisher=Harvard University Press |isbn=978-0-674-02163-1 |pages=141–144}}</ref>

==Life cycle==
[[File:Anisomorpha-male-female.jpg|thumb|Mating pair of ''[[Anisomorpha buprestoides]]'']]
The life cycle of the stick insect begins when the female deposits her eggs through one of these methods of [[Oviparity|oviposition]]: she will either flick her egg to the ground by a movement of the ovipositor or her entire abdomen, carefully place the eggs in the axils of the host plant, bury them in small pits in the soil, or stick the eggs to a [[substrate (biology)|substrate]], usually a stem or leaf of the food plant. A single female lays from 100 to 1,200 eggs after mating, depending on the species.<ref name="bedford" />

Many species of phasmids are [[parthenogenic]], meaning the females lay eggs without needing to mate with males to produce offspring. Eggs from virgin mothers are entirely female and hatch into nymphs that are exact copies of their mothers. Stick insect species that are the product of [[Hybrid (biology)|hybridisation]] are usually [[Parthenogenesis#Life history types|obligate]] [[Parthenogenesis|parthenogens]],<ref name="MR2005">{{Cite journal | last1 = Morgan-Richards | first1 = M. | last2 = Trewick | first2 = S. A. | doi = 10.1111/j.1365-294X.2005.02575.x | title = Hybrid origin of a parthenogenetic genus? | journal = Molecular Ecology | volume = 14 | issue = 7 | pages = 2133–2142 | year = 2005 | pmid = 15910332 | s2cid = 29709325}}</ref> but non-hybrids are [[Parthenogenesis#Life history types|facultative parthenogens]], meaning they retain the ability to [[sexual reproduction|mate]] and their sexual behavior depends on the presence and abundance of males.<ref name="MR2010">{{Cite journal | last1 = Morgan-Richards | first1 = M. | last2 = Trewick | first2 = S. A. | last3 = Stringer | first3 = I. N. A. N. | doi = 10.1111/j.1365-294X.2010.04542.x | title = Geographic parthenogenesis and the common tea-tree stick insect of New Zealand | journal = Molecular Ecology | volume = 19 | issue = 6 | pages = 1227–1238 | year = 2010 | pmid = 20163549| bibcode = 2010MolEc..19.1227M | s2cid = 25972583}}</ref>

Reproduction by androgenesis has also been recorded in stick insects of the genus [[Bacillus_(insect)|Bacillus]] such as ''Bacillus rossius'' and ''Bacillus grandii''.<ref>{{cite journal |last1=Tinti |first1=Fausto |last2=Scali |first2=Valerio |title=Genome exclusion and gametic dapi—dna content in the hybridogenetic Bacillus rossius—grandii benazzii complex (insecta phasmatodea) |journal=Molecular Reproduction and Development |date=November 1992 |volume=33 |issue=3 |pages=235–242 |doi=10.1002/mrd.1080330302 |pmid=1449790 }}</ref>

Phasmatodea eggs resemble seeds in shape and size and have hard shells. They have a lid-like structure called an [[operculum (animal)|operculum]] at the [[anterior pole]], from which the nymph emerges during hatching. The eggs vary in the length of time before they hatch which varies from 13 to more than 70 days, with the average around 20 to 30 days.<ref name="bedford" /> Some species, particularly those from [[temperate]] regions, undergo [[diapause]], where development is delayed during the winter months. Diapause is initiated by the effect of [[Photoperiodism|short day lengths]] on the egg-laying adults or can be genetically determined. Diapause is broken by exposure to the cold of winter, causing the eggs to hatch during the following spring. Among species of economic importance such as ''[[Diapheromera femorata]]'', diapause results in the development of two-year cycles of outbreaks.<ref name=Resh>{{cite book|author1=Resh, Vincent H. |author2=Cardé, Ring T. |title=Encyclopedia of Insects |url=https://books.google.com/books?id=Jk0Hym1yF0cC&pg=PA392 |year=2009|publisher=Academic Press |isbn=978-0-08-092090-0 |page=392}}</ref>

[[File:21 Phasmid Eggs.jpg|thumb|left|Eggs of various phasmid species (not to scale)]]

Many species' eggs bear a fatty, knoblike [[Ant mimicry#Stick insects|capitulum]] that caps the operculum. This structure attracts ants because of its resemblance to the [[elaiosome]] of some plant seeds that are sought-after food sources for ant larvae, and usually contribute to ensuring seed dispersal by ants, a form of ant-plant mutualism called [[myrmecochory]]. The ants take the egg into their nest underground and can remove the capitulum to feed to their larvae without harming the phasmid embryo. There, the egg hatches and the young nymph, which initially [[ant mimicry|resembles an ant]] (another instance of mimicry among Phasmatodea), eventually emerges from the nest and climbs the nearest tree to safety in the foliage.<ref name="bedford" /> The eggs of stick insects have a coating of calcium oxalate which makes them survive unscathed in the digestive tract of birds. It has been suggested that birds may have a role in the dispersal of parthenogenetic stick insect species, especially to islands.<ref>{{Cite journal|last1=Suetsugu|first1=Kenji|last2=Funaki|first2=Shoichi|last3=Takahashi|first3=Asuka|last4=Ito|first4=Katsura|last5=Yokoyama|first5=Takeshi|date=2018-05-29|title=Potential role of bird predation in the dispersal of otherwise flightless stick insects|journal=Ecology|volume=99|issue=6|pages=1504–1506|language=en|doi=10.1002/ecy.2230|pmid=29809279|bibcode=2018Ecol...99.1504S |hdl=20.500.14094/90004770 |s2cid=46920315|issn=0012-9658|hdl-access=free}}</ref>

The Phasmatodea life cycle is [[hemimetabolous]], proceeding through a series of several nymphal [[instar]]s. Once emerged, a nymph will eat its cast skin. Adulthood is reached for most species after several months and many molts. The lifespan of Phasmatodea varies by species, but ranges from a few months to up to three years.<ref name=NatGeographic>{{cite web |url=http://animals.nationalgeographic.com/animals/bugs/stick-insect/ |archive-url=https://web.archive.org/web/20100111130100/http://animals.nationalgeographic.com/animals/bugs/stick-insect/ |url-status=dead |archive-date=11 January 2010 |title=Stick Insect: Phasmida |work=Animals A-Z |date=12 March 2010 |publisher=National Geographic |access-date=10 October 2015}}</ref>

==Ecology==
Phasmids are herbivorous, feeding mostly on the leaves of trees and shrubs, and a conspicuous component of many [[Neotropical]] systems. Phasmatodea has been postulated as dominant [[light-gap]] herbivores there. Their role in the forest ecosystem is considered important by many scientists, who stress the significance of light gaps in maintaining [[ecological succession|succession]] and resilience in [[climax vegetation|climax forests]]. The presence of phasmids lowers the net production of early successional plants by consuming them and then enriches the soil by [[defecation]]. This enables the late succession plants to become established and encourages the recycling of the tropical forest.<ref>{{cite journal|last=Willig|first=Michael R. |author2=Rosser W. Garrison |author3=Arlene J. Bauman|title=Population dynamics and natural history of a neotropical walking stick, Lamponius Portoricensis Rehn (Phasmatodea: Phasmatidae)|journal=The Texas Journal of Science |year=1986|volume=38}}</ref>

Phasmatodea are recognized as injurious to forest and shade trees by [[Folivore|defoliation]]. ''[[Didymuria violescens]]'', ''[[Podacanthus wilkinsoni]]'' and ''[[Ctenomorphodes tessulatus]]'' in Australia, ''[[Diapheromera femorata]]'' in [[North America]] and ''[[Graeffea crouani]]'' in coconut plantations in the [[Oceania|South Pacific]] all occur in outbreaks of economic importance.<ref name="Baker 2015">{{cite journal |last=Baker |first=E. |date=2015 |title=The worldwide status of stick insects (Insecta: Phasmida) as pests of agriculture and forestry, with a generalised theory of phasmid outbreaks |journal=Agriculture and Food Security |volume=4 |issue=22 |doi=10.1186/s40066-015-0040-6 |doi-access=free|hdl=10141/615363 |hdl-access=free }}</ref> Indeed, in the [[American South]], as well as in [[Michigan]] and [[Wisconsin]], the walking stick is a significant problem in parks and recreation sites, where it consumes the foliage of [[oak]]s and other [[hardwood]]s. Severe outbreaks of the walking stick, ''Diapheromera femorata'', have occurred in the [[Ouachita Mountains]] of [[Arkansas]] and [[Oklahoma]]. The insects eat the entire leaf blade. In the event of heavy outbreaks, entire stands of trees can be completely denuded.<ref name=Craighead>{{cite book|author1=Craighead, Frank Cooper |author2=Schaffner, John Valentine |title=Insect Enemies of Eastern Forests|url=https://books.google.com/books?id=Y34WAAAAYAAJ&pg=PA97 |year=1950 |publisher=U.S. Government Printing Office |pages=97–98}}</ref> Continuous defoliation over several years often results in the death of the tree. Because these species cannot fly, infestations are typically contained to a radius of a few hundred yards. Nevertheless, the damage incurred to parks in the region is often costly. Control efforts in the case of infestations have typically involved chemical [[pesticide]]s; ground fires are effective at killing eggs but have obvious disadvantages.<ref name=Craighead/> In New South Wales, research has investigated the feasibility of controlling stick insects using natural enemies such as [[parasitic wasps]] (''Myrmecomimesis'' spp.).<ref name="Campbell, K.G. 1959 19–23">{{cite journal |author=Campbell, K.G. |year=1959 |title=The importance of research into forest insect problems in New South Wales |journal=Australian Forestry |volume=23 |issue=1 |pages=19–23 |doi=10.1080/00049158.1959.10675860|bibcode=1959AuFor..23...19C }}</ref>

==Taxonomy==
[[File:Phyllium bilobatum, male larva.jpg|thumb|upright|True leaf insects, like this ''[[Phyllium bilobatum]]'', belong to the family [[Phylliidae]].]]
The classification of the Phasmatodea is complex and the relationships between its members are poorly understood.<ref>{{cite web |url=http://www.phasmatodea.com/web/guest/classification |title=Classification of the Phasmatodea |publisher=Phasmatodea.com |access-date=2 October 2015 |archive-url=https://web.archive.org/web/20151003130026/http://www.phasmatodea.com/web/guest/classification |archive-date=3 October 2015 |url-status=dead}}</ref> Furthermore, there is much confusion over the ordinal name. Phasmida is preferred by many authors, though it is [[International Code of Zoological Nomenclature|incorrectly formed]];{{citation needed|date=August 2019}} Phasmatodea is correctly formed, and is widely accepted.<ref name=Zompro/> However, Brock and Marshall argue:<ref>{{cite book |first1=Paul D. |last1=Brock |first2=Judith |last2=Marshall |year=2011 |chapter=Order Phasmida Leach. 1815. |editor-last1= Zhang |editor-first1=Z.-Q. |title=Animal biodiversity: An outline of higherlevel classification and survey of taxonomic richness |chapter-url=https://www.mapress.com/zootaxa/2011/f/zt03148p198.pdf}}</ref>

{{blockquote|Phasmida is the oldest and simplest name, first used by Leach in 1815 in "Brewster’s Edinburgh Encyclopaedia" volume 9, p.&nbsp;119, and widely used in major entomological textbooks, dictionaries and many scientific papers and books on phasmids. As there is no compulsion to select the "grammatically correct" name [which some argue is Phasmatodea Jacobson & Bianchi, 1902], selection of a long established (and simple) name is reasonable, although the probability of persuading all colleagues to agree on the use of Phasmida is unlikely.}}

The order Phasmatodea is sometimes considered to be related to other orders, including the [[Blattodea]], [[Mantodea]], [[Grylloblattodea]], [[Mantophasmatodea]] and [[Dermaptera]], but the affiliations are uncertain and the grouping (sometimes referred to as "Orthopteroidea") may be [[paraphyletic]] (not have a common ancestor) and hence invalid in the traditional [[Circumscription (taxonomy)|circumscription]] (set of attributes that all members have). Phasmatodea, once considered a suborder of [[Orthoptera]], is now treated as an order of its own.<ref name=PSF>{{cite web|last1=Brock|first1=Paul D.|title=Phasmida Species File Online. Version 5.0|url=http://phasmida.speciesfile.org/HomePage/Phasmida/HomePage.aspx|access-date=2 October 2015}}</ref> Anatomical features separate them as a [[monophyletic]] (descended from a common ancestor) group from the Orthoptera. One is the instance among all species of Phasmatodea of a pair of [[exocrine gland]]s inside the prothorax used for defense. Another is the presence of a specially formed [[sclerite]] (hardened plate), called a vomer, which allows the male to clasp the female during mating.<ref name="Oxford Reference Online">{{cite book |last=O'Toole |first=Christopher |title=Leaf and Stick Insects |year=2002 |url=https://www.oxfordreference.com/view/10.1093/acref/9780198525059.001.0001/acref-9780198525059-e-18?rskey=jmOpW1&result=1 |publisher=Oxford University Press|isbn=978-0-19-852505-9 }}</ref>

The order is divided into two, or sometimes three, suborders.<ref name="Oxford Reference Online" /> The traditional division is into the suborder groups Anareolatae and Areolatae, which are distinguished according to whether the insect has sunken areola, or circular areas, on the underside of the apices of the middle and hind tibiae (Areolate) or not (Anareolate). However the [[phylogenetic]] (evolutionary) relationships between the different groups is poorly resolved. The [[monophyly]] of Anareolatae has been questioned and the [[Morphology (biology)|morphology]] of the eggs may be a better basis for classification.<ref name=Zompro>{{cite journal |author=Zompro, O. |year=2004 |title=Revision of the genera of the Areolatae, including the status of ''Timema'' and ''Agathemera'' (Insecta: Phasmatodea) |journal=Organización Para Estudios Tropicales, (OET), Costa Rica Bibliografía Nacional en Biología Tropical (BINABITROP) |volume=37 |pages=1–327 |url=http://www.sidalc.net/cgi-bin/wxis.exe/?IsisScript=OET.xis&method=post&formato=2&cantidad=1&expresion=mfn=027215 |archive-url=https://web.archive.org/web/20151003180430/http://www.sidalc.net/cgi-bin/wxis.exe/?IsisScript=OET.xis&method=post&formato=2&cantidad=1&expresion=mfn=027215 |archive-date=3 October 2015 |url-status=dead}}</ref> An alternative is to divide the Phasmatodea into three suborders [[Agathemerodea]] (1 genus and 8 species), [[Timematodea]] (1 genus and 21 species) and [[Euphasmatodea]] (or Verophasmatodea) for the remaining [[taxa]].<ref name=Biodiversity>{{cite book|title=Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness |url=https://books.google.com/books?id=r3_DVd5DtGEC&pg=PA198 |year=2011 |publisher=Magnolia Press |isbn=978-1-86977-849-1 |page=198}}</ref> This division is, however, not fully supported by the molecular studies, which recover Agathemerodea as nested within Euphasmatodea rather than being the sister group of the latter group.<ref>{{Cite journal|author1=Thomas R. Buckley |author2=Dilini Attanayake |author3=Sven Bradler |year=2009 |title=Extreme convergence in stick insect evolution: phylogenetic placement of the Lord Howe Island tree lobster |journal=Proceedings of the Royal Society B: Biological Sciences |volume=276 |issue=1659 |pages=1055–1062 |doi=10.1098/rspb.2008.1552 |pmid=19129110 |pmc=2679072}}</ref><ref>{{Cite journal|author1=Sven Bradler |author2=James A. Robertson |author3=Michael F. Whiting |year=2014 |title=A molecular phylogeny of Phasmatodea with emphasis on Necrosciinae, the most species-rich subfamily of stick insects |journal=Systematic Entomology |volume=39 |issue=2 |pages=205–222 |doi=10.1111/syen.12055 |bibcode=2014SysEn..39..205B |s2cid=85794995}}</ref><ref name=SF-Phasmida>{{cite speciesfile|phasmida|id=851140 |title=Phasmida Leach, 1815 |access-date=15 June 2024}}</ref> Recent taxonomic treatments recognise two suborders,<ref name=SF-Phasmida/> with [[Agathemeridae]] placed in [[Pseudophasmatoidea]] within Euphasmatodea<ref>{{cite speciesfile|phasmida|id=852046 |title=Agathemeridae Bradler, 2003|access-date=15 June 2024}}</ref> and Agathemerodea treated as ''[[nomen dubium]]''<ref>{{cite speciesfile|phasmida|id=851143 |title=Agathemerodea Zompro, 2004|access-date=15 June 2024}}</ref>

While suggestions have been made that various insects extending back to the [[Permian]] epoch represent stem-group phasmatodeans, the earliest unambiguous members of the group are the [[Susumanioidea]], which first appeared during the Middle [[Jurassic Park|Jurassic]], and usually have two large pairs of wings. Modern phasmatodeans first appeared during the Early [[Cretaceous]], with the currently oldest known being ''[[Araripephasma]]'' from the Early Cretaceous ([[Aptian]]) [[Crato Formation]] of Brazil, around 113 million years old, which can be confidently assigned to the Euphasmatodea.<ref>{{Cite journal |last1=Ghirotto |first1=Victor M. |last2=Crispino |first2=Edgar B. |last3=Chiquetto-Machado |first3=Pedro I. |last4=Neves |first4=Pedro A. B. A. |last5=Engelking |first5=Phillip W. |last6=Ribeiro |first6=Guilherme C. |date=May 2022 |editor-last=Labandeira |editor-first=Conrad |title=The oldest Euphasmatodea (Insecta, Phasmatodea): modern morphology in an Early Cretaceous stick insect fossil from the Crato Formation of Brazil |url=https://onlinelibrary.wiley.com/doi/10.1002/spp2.1437 |journal=Papers in Palaeontology |language=en |volume=8 |issue=3 |doi=10.1002/spp2.1437 |bibcode=2022PPal....8E1437G |s2cid=249738376 |issn=2056-2799|url-access=subscription }}</ref>

The earliest leaf insect (Phylliinae) fossil is ''[[Eophyllium messelensis]]'' from the 47-million-year-old [[Eocene]] of Messel, Germany. In size and cryptic (leaflike) body form, it closely resembles extant species, suggesting that the behavior of the group has changed little since that time.<ref>{{cite journal |last1=Wedmann |first1=Sonja |last2=Bradler |first2=Sven |last3=Rust |first3=Jes |title=The first fossil leaf insect: 47 million years of specialized cryptic morphology and behavior |journal=PNAS |date=2006 |volume=104 |issue=2 |pages=565–569 |doi=10.1073/pnas.0606937104 |pmid=17197423 |pmc=1766425|doi-access=free }}</ref>

Over 3,500 species have been described, with many more yet to be described both in museum collections and in the wild.<ref>Bragg, P.E. (2001) ''Phasmids of Borneo'', Natural History Publications (Borneo), Kota Kinabalu. - see p. 614.</ref><ref name=SF-Phasmida/>

{| class="wikitable" style="margin:auto; width:100%;"
!Suborders
!No. of species
!Defining notes
!Image
|-
|[[Timematodea]]
|21<ref>{{cite speciesfile|phasmida|id=851144 |title=Timematodea Kevan, 1977|access-date=15 June 2024}}</ref> 
|Considered earliest to branch from phylogenetic tree
|[[File:Timema dorotheae.jpg|thumb|center|upright|''Timema dorotheae'']]
|-
|[[Euphasmatodea]]
|3514<ref>{{cite speciesfile|phasmida|id=851173 |title=Euphasmatodea Bradler, 1999|access-date=15 June 2024}}</ref> 
|Vast majority of extant species
|[[File:DonovanEpitomePlate9.jpg|thumb|center|upright|''Phasma gigas'']]
|}

==Select species==
[[File:Acanthoxyla prasina.JPG|thumb|''[[Acanthoxyla prasina]]'', or the prickly stick insect, native to [[New Zealand]], is believed to reproduce by [[parthenogenesis]]; no males were recorded<ref name="odt">"[http://www.odt.co.nz/news/dunedin/194387/insect-poses-prickly-questions Insect poses prickly questions]" on ''[[Otago Daily Times]]'' website, viewed 2013-10-16</ref> until 2016, when a single male was discovered in the UK where this lineage has been introduced.<ref>{{Cite journal|last=Brock|first=Paul|date=2018|title=Missing stickman found: The first male of the parthenogenetic New Zealand Phasmid genus Acanthoxyla Uvarov, 1944 discovered in the United Kingdom|journal=Atropos|volume=60|pages=16–23}}</ref>|alt=]]
One Australian species, the [[Lord Howe Island stick insect]], is now listed as critically endangered. It was believed extinct until its rediscovery on the rock known as [[Ball's Pyramid]].<ref>{{cite iucn |author=Rudolf, E. |author2=Brock, P. |date=2017 |title=''Dryococelus australis'' |volume=2017 |page=e.T6852A21426226 |doi=10.2305/IUCN.UK.2017-3.RLTS.T6852A21426226.en |access-date=13 November 2021}}</ref> An effort is underway in Australia to rear this species in [[captivity (animal)|captivity]].

The best known of the stick insects is the Indian or laboratory stick insect (''[[Carausius morosus]]''). This insect grows to roughly 10&nbsp;cm (4&nbsp;in) and reproduces [[parthenogenesis|parthenogenically]], and although males have been recorded, they are rare.<ref>{{cite web |url=http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74157.html |title=Indian walking stick |author1=Headrick, D.H. |author2=Walen, C.A. |date=1 May 2011 |work=Pests in Gardens and Landscapes |publisher=UC IPM |access-date=10 October 2015}}</ref>

Fossils of the extinct genus and species ''[[Eoprephasma hichensi]]'' have been recovered from [[Ypresian]] age sediments in the U.S. state of [[Washington (state)|Washington]] and [[British Columbia]], Canada. The species is one of the youngest members of the stem phasmatodean group [[Susumanioidea]].<ref name="Archibald2015">{{cite journal |last1=Archibald |first1=SB |last2=Bradler |first2=S |year=2015 |title=Stem-group stick insects (Phasmatodea) in the early Eocene at McAbee, British Columbia, Canada, and Republic, Washington, United States of America |journal=Canadian Entomologist |volume=147 |issue=6 |doi=10.4039/tce.2015.2 |pages=1–10|s2cid=86608533 }}</ref>

=== European species ===
In Europe there are 17 species of stick insects described, belonging to the genera ''[[Bacillus (animal)|Bacillus]]'' ''[[Clonopsis]]'', ''[[Leptynia]]'' and ''[[Pijnackeria]]''. There are also a few other species that live in Europe but are introduced, as for example with a couple of species of ''[[Acanthoxyla]]'', which are native to New Zealand but are present in southern England.

In the Iberian Peninsula there are currently described 13 species and several subspecies. Their life cycle is annual, living only during the hottest months (especially genera ''Leptynia'' and ''Pijnackeria''), which usually means late spring to early autumn.

<gallery class="center">
File:LeafInsect.jpg|''[[Phyllium]]'' sp., from the [[Western Ghats]]
File:Clonopsis gallica01.jpg|''[[Clonopsis gallica]]''
File:Ctenomorpha chronus02.jpg|''[[Ctenomorpha marginipennis]]''
File:Leptynia hispanica.png|''[[Leptynia hispanica]]''
</gallery>

==Behavior==
[[File:Poke It Stick.ogv|thumb|Video of a walking phasmid]]
Stick insects, like [[praying mantis]]es, show rocking behavior in which the insect makes rhythmic, repetitive, side-to-side movements. The common interpretation of this behavior's function is it enhances [[crypsis]] by mimicking vegetation moving in the wind. These movements may also be important in allowing the insects to discriminate objects from the background by relative motion. Rocking movements by these generally sedentary insects may replace flying or running as a source of relative motion to help them discern objects in the foreground.<ref>O'Dea, JD. Eine zusatzliche oder alternative Funktion der 'kryptischen' Schaukelbewegung bei Gottesanbeterinnen und Stabschrecken (Mantodea, Phasmatodea). Entomologische Zeitschrift, 101, Nr. 1/2, 15 Januar 1991, 25-27.</ref>

Mating behavior in Phasmatodea is impressive because of the extraordinarily long duration of some pairings. A record among insects, the stick insect ''[[Necroscia sparaxes]]'', found in India, is sometimes coupled for 79 days at a time. It is not uncommon for this species to assume the [[mating posture]] for days or weeks on end, and among some species (''[[Diapheromera veliei]]'' and ''[[Diapheromera covilleae|D. covilleae]]''), pairing can last three to 136 hours in captivity.<ref name="siv1980">{{cite journal| last=Sivinski| first=John| title=Effects of Mating on Predation in the Stick Insect ''Diapheromera veliei'' Walsh (Phasmatodea: Heteronemiidae)| journal=Annals of the Entomological Society of America| year=1980| volume=73 |issue=5 |doi=10.1093/aesa/73.5.553 |pages=553–556}}</ref>

Overt displays of aggression between males over mates suggests that extended pairing may have [[evolved]] to guard females from [[sperm competition]]. Fighting between competing males has been observed in the species ''D. veiliei'' and ''D. covilleae''.<ref name="siv1978">{{cite journal|last=Sivinski|first=John|title=Intersexual Aggression in the Stick Insects ''Diapheromera veliei'' and ''D. covilleae'' and Sexual Dimorphism in the Phasmatodea| journal=Psyche: A Journal of Entomology| year=1978| volume=85| issue=4 |doi=10.1155/1978/35784 |pages=395–403|doi-access=free}}</ref> During these encounters, the approach of a challenger causes the existing mate to manipulate the female's abdomen, which he has clasped by means of the clasping organ, or vomer, down upon itself to block the site of attachment. Occasionally, the consort will strike out at the competitor with the mid femora, which are equipped with an enlarged and hooked spine in both sexes that can draw the blood of the opponent when they are flexed against the body to puncture the [[integument]].<ref name="siv1978" /> Usually, a strong hold on the female's abdomen and blows to the intruder are enough to deter the unwanted competition, but occasionally the competitor has been observed to employ a sneaky tactic to [[inseminate]] the female. While the first mate is engaged in feeding and is forced to vacate the [[Anatomical terms of location#Dorsal and ventral|dorsal]] position, the intruder can clasp the female's abdomen and insert his [[genitalia]]. If he is discovered, the males will enter into combat wherein they lean backward, both clasped to the female's abdomen, and freely suspended, engage in rapid, sweeping blows with their forelegs in a manner similar to [[boxing]]. Usually, when the intruder gains attachment to the female's abdomen, these conflicts result in the displacement of the original mate.<ref name="siv1978" />

[[File:Indische Stabschrecke auf einem Himbeerblatt im Terrarium.jpg|thumb|upright|''[[Carausius morosus]]'' is often kept as a pet by schools and individuals.]]

Lengthy pairings have also been described in terms of a defensive alliance. When cleaved together, the pair is more unwieldy for predators to handle. Also, the chemical defenses (secretions, reflex bleeding, regurgitation) of the individual stick insect are enhanced when two are paired. Females survive attacks by predators significantly better when pairing, largely because the dorsal position of the male functions well as a shield. This could indicate that manipulation by females is taking place: if females accept [[ejaculate]] at a slow rate, for instance, the males are forced to remain [[copulation (zoology)|''in copulo'']] for longer and the female's chances of survival are enhanced. Also, evolution could have simply favored males that remained attached to their females longer, since females are often less abundant than males and represent a valuable prize, so for the lucky male, even the sacrifice of his own life to preserve his [[offspring]] with the female may be worthwhile. [[Sexual dimorphism]] in the species, where females are usually significantly larger than the males, may have evolved due to the fitness advantage accrued to males that can remain attached to the female, thereby blocking competitors, without severely impeding her movement.<ref name="siv1980" />

Certain Phasmatodea, such as ''Anisomorpha buprestoides'', sometimes form aggregations. These insects have been observed to congregate during the day in a concealed location, going their separate ways at nightfall to forage, and returning to their refuge before dawn. Such behavior has been little studied, and how the insects find their way back is unknown.<ref name=Costa/>

==In human culture==

[[File:Leaf Insects and Stick Insects Marianne North.jpg|thumb|upright|Painting of Stick Insects by [[Marianne North]], 1870s]]

Stick insects are often kept in captivity: almost 300 species have been reared in laboratories or as pets.<ref>{{cite journal | last1 = Bragg | first1 = P | year = 2008 | title = Changes to the PSG Culture List | journal = Phasmid Study Group Newsletter | volume = 113 | pages = 4–5}}</ref> The most commonly kept is the Indian (or laboratory) stick insect, ''[[Carausius morosus]]'', which eats vegetables such as lettuce.<ref>{{cite journal |last=Boucher |first=Stephanie |author2=Hirondelle Varady-Szabo |title=Effects of different diets on the survival, longevity and growth rate of the Annam stick insect, Medauroidea extradentata (Phasmatodea: Phasmatidae) |journal=Journal of Orthoptera Research |year=2005 |volume=14 |pages=115–118 |doi=10.1665/1082-6467(2005)14[115:eoddot]2.0.co;2|s2cid=86169927 |type=Submitted manuscript}}</ref> Droppings of the stick insect ''[[Eurycnema versirubra]]'' (Serville, 1838) [=''Eurycnema versifasciata''] fed with specific plants are made into a medicinal [[insect tea|tea]] by Malaysian Chinese to treat ailments.<ref>{{cite journal|author=Nadchatram, M.|year=1963|title= The winged stick insect, Eurycnema versifasciata Serville (Phasmida, Phasmatidae), with special reference to its life history|journal= Malayan Nature Journal|volume=17|pages=33–40}}</ref>

The [[botanical illustrator]] [[Marianne North]] (1830–1890) painted leaf and stick insects that she saw on her travels in the 1870s.<ref>{{cite web |last1=North |first1=Marianne|title=Leaf-Insects and Stick-Insects |url=https://artuk.org/discover/artworks/leaf-insects-and-stick-insects-88081 |website=[[Art UK]] |access-date=2 October 2015}}</ref>

Tribesmen in [[Sarawak]] eat phasmids and their eggs.<ref>{{cite journal |author=Baker, Edward |title=The worldwide status of phasmids (Insecta: Phasmida) as pests of agriculture and forestry, with a generalised theory of phasmid outbreaks | journal=Agriculture and Food Security |date=2015 |doi=10.1186/s40066-015-0040-6 |volume=4|issue=1 |page=22 |hdl=10141/615363 |s2cid=17881709 |url=https://nhm.openrepository.com/bitstream/10141/615363/3/Baker%202015.pdf|hdl-access=free |doi-access=free |bibcode=2015AgFS....4...22B }}</ref>

Some indigenous people of the [[D'Entrecasteaux Islands]] have traditionally made fishhooks from the legs of certain phasmids.<ref>{{cite book |last1=Osmond |first1=Meredith |editor-last1=Ross |editor-first1=Malcolm |editor-last2=Pawley |editor-first2=Andrew |editor-last3=Osmond |editor-first3=Meredith|title=The lexicon of Proto Oceanic vol. 1 Material culture |date=1998 |publisher=Pacific Linguistics |location=Canberra |isbn=0-85883-507-X |page=219 |chapter=Chapter 8: Fishing and Hunting Implements |url=https://openresearch-repository.anu.edu.au/handle/1885/106908 |access-date=9 February 2020 |doi=10.15144/PL-C152.211}}</ref>
 
Research has been conducted to analyze the stick insect method of walking and apply this to the engineering of six-legged [[walking robot]]s. Instead of one centralized [[control system]], it seems each leg of a phasmid operates independently.<ref>{{Cite journal |author1=Dean, Jeffery |author2=Kindermann, Thomas |author3=Schmitz, Josef |author4=Schumm, Michael |author5=Cruse, Holk |date=1999 |title=Control of Walking in the Stick Insect: From Behavior and Physiology to Modeling |journal=Autonomous Robots |volume=7 |issue=3 |pages=271–288 |doi= 10.1023/A:1008980606521|s2cid=46306252}}</ref>

In [[Australia]] and [[Hawaii]] many kinds of stick insects are kept as [[exotic pet]]s including the strong, [[Eurycnema goliath|goliath]], [[Extatosoma tiaratum|spiny]] and [[Tropidoderus childrenii|children's]]. The custom of keeping stick insects as pets was probably brought to Australia by either [[Chinese people|Chinese]], [[Japanese people|Japanese]] or [[Vietnamese people|Vietnamese]] immigrants during [[World War II]], the [[Korean War]] or the [[Vietnam War]].

Stick insects have been kept as pets since the time of the [[Han dynasty]]. They were kept inside [[birdcage]]s and people in the Far East believe they bring good luck and [[Wealth|fortune]], just like [[crickets]].<ref>{{Cite web |url=https://australian.museum/learn/animals/insects/care-of-stick-insects/ |title=Care of Stick Insects - Australian Museum|website=australia.nmuseum|access-date=8 May 2016}}</ref>

The video game ''[[Disco Elysium]]'' includes a storyline centered around a giant stick insect and [[cryptid]] called the insulindian phasmid.

A clip of a stick insect swaying back and forth, in a manner akin to dancing, became an Internet meme in 2020 as a [[bait-and-switch]].<ref>{{cite news|url=https://www.fsunews.com/story/news/2020/12/06/our-turn-2020-s-best-meme/6455867002/|title=Our Turn: 2020's Best Meme|newspaper=[[FSView & Florida Flambeau]]|date=December 6, 2020|access-date=November 10, 2024}}</ref>

==References==
{{Reflist|28em}}

==External links==
{{Commons category|Phasmatodea}}
{{Wikispecies}}
* [http://phasmid-study-group.org/ The Phasmid Study Group]
* [http://www.phasmatodea.com/ Phasmatodea.com]
* [http://phasmida.speciesfile.org/HomePage/Phasmida/HomePage.aspx Phasmida Species File]
* [https://www.landcareresearch.co.nz/discover-our-research/biodiversity/plants-invertebrates-fungi-and-bacteria/invertebrate-systematics/stick-insects/ New Zealand Stick Insect Web Site]
* [http://www.asper.org/ ASPER: Lesser Antilles and French stick insects]
<!-- ==============================({{NoMoreLinks}})============================== -->
<!-- DO NOT ADD MORE LINKS TO THIS ARTICLE UNLESS THEY CONFORM TO [[WP:EL]]. WIKIPEDIA IS NOT A COLLECTION OF LINKS -->
<!-- ============================================================================= -->

{{Orders of Insects}}
{{Phasmatodea}}

{{Taxonbar|from=Q188029}}
{{Authority control}}

{{Good article}}

{{DEFAULTSORT:Phasmatodea}}
[[Category:Phasmatodea| ]]
[[Category:Insect orders]]
[[Category:Articles containing video clips]]
[[Category:Cenomanian first appearances]]
[[Category:Extant Late Cretaceous first appearances]]
[[Category:Orthopterida]]