Editing Phasmatodea (section)

==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>