Editing Pheromone (section)

==Categorization by function==

===Aggregation===
[[Image:Bug aggregation.jpg|right|thumb|Aggregation of bug nymphs]]
[[File:Podura aquatica Podkomorské lesy.jpg|thumb|Aggregation of the water [[springtail]] ''[[Podura aquatica]]'']]
Aggregation pheromones function in [[mate choice]], overcoming host resistance by mass attack, and defense against predators. A group of individuals at one location is referred to as an aggregation, whether consisting of one sex or both sexes. Male-produced sex attractants have been called aggregation pheromones, because they usually result in the arrival of both sexes at a calling site and increase the density of conspecifics surrounding the pheromone source. Most sex pheromones are produced by the females; only a small percentage of sex attractants are produced by males.<ref>{{cite web|url=https://www.msu.edu/user/miller20/carmona.htm|title=Insect aggregation pheromones|website=www.msu.edu|access-date=19 February 2018}}</ref> Aggregation pheromones have been found in members of the [[Coleoptera]], [[Springtail|Collembola]],<ref>{{Cite journal | vauthors = Salmon S, Rebuffat S, Prado S, Sablier M, d'Haese C, Sun JS, Ponge JF |date=2019-05-20 |title=Chemical communication in springtails: a review of facts and perspectives |journal=Biology and Fertility of Soils |volume=55 |issue=5 |pages=425–438 |doi=10.1007/s00374-019-01365-8 |bibcode=2019BioFS..55..425S |s2cid=159042283 |issn=0178-2762|url=https://hal.archives-ouvertes.fr/hal-02152310/file/Chemical%20communication%20in%20springtails%20final%20version.pdf }}</ref> [[Diptera]], [[Hemiptera]], [[Dictyoptera]], and [[Orthoptera]]. In recent decades, aggregation pheromones have proven useful in the management of many pests, such as the boll weevil (''[[Anthonomus grandis]]''), the pea and bean weevil (''[[Sitona lineatus]]'', and stored product weevils (e.g. ''[[Sitophilus zeamais]]'', ''[[Sitophilus granarius]]'', and ''[[Sitophilus oryzae]]''). Aggregation pheromones are among the most ecologically selective pest suppression methods. They are non-toxic and effective at very low concentrations.<ref>{{cite journal | vauthors = Landolt JP |title=Sex attractant and aggregation pheromones of male phytophagous insects |journal=American Entomologist |volume=43 |issue=1 |pages=12–22 |year=1997 |doi= 10.1093/ae/43.1.12|doi-access=free }}</ref>

===Alarm===
{{Main|Alarm signal}}
Some species release a volatile substance when attacked by a predator that can trigger flight (in [[aphid]]s) or aggression (in [[ant]]s, [[bee]]s, [[termite]]s, and [[wasp]]s)<ref>{{cite journal | vauthors = Sobotník J, Hanus R, Kalinová B, Piskorski R, Cvacka J, Bourguignon T, Roisin Y | title = (E,E)-alpha-farnesene, an alarm pheromone of the termite Prorhinotermes canalifrons | journal = Journal of Chemical Ecology | volume = 34 | issue = 4 | pages = 478–486 | date = April 2008 | pmid = 18386097 | doi = 10.1007/s10886-008-9450-2 | bibcode = 2008JCEco..34..478S | s2cid = 8755176 | citeseerx = 10.1.1.673.1337 }}</ref><ref>{{cite journal | last1 = Wood | first1 = William F. | last2 = Chong | first2 = Berni  |  year = 1975 | title = 3-Octanone and 3-Octanol; Alarm Pheromones from East African Acacia Ants | journal = Journal of the Georgia Entomological Society | volume = 10 | pages = 332–334}}</ref><ref>{{cite journal | last1 = Wood | first1 = William F. | last2 = Palmer | first2 = Todd M. | last3 = Stanton | first3 = Maureen L. | year = 2002 | title = A comparison of volatiles in mandibular glands from three Crematogaster ant symbionts of the whistling thorn acacia | journal = J Biochemical Systematics and Ecology | volume = 30 | issue = 3 | pages = 217–222 | doi=10.1016/S0305-1978(01)00099-0| bibcode = 2002BioSE..30..217W }}</ref><ref>{{cite journal | last1 = Wood | first1 = William F. | last2 = Hoang | first2 = Thuy-Tien | last3 = McGlynn | first3 = Terrence P. | year = 2011 | title = Volatile components from the mandibular glands of the turtle ants, Cephalotes alfaroi and C. cristatus | journal = Biochemical Systematics and Ecology | volume = 39 | pages = 135–138 | doi=10.1016/j.bse.2011.01.013 }}</ref><ref>{{cite journal | last1 = Wood | first1 = William F. | year = 2005 | title = Comparison of mandibular gland volatiles from ants of the bull horn acacia, Acacia collinsii | journal = Biochemical Systematics and Ecology | volume = 33 | issue = 7 | pages = 651–658 | doi=10.1016/j.bse.2004.12.009| bibcode = 2005BioSE..33..651W }}</ref> in members of the same species. For example, ''[[Vespula squamosa]]'' use alarm pheromones to alert others to a threat.<ref>Landoldt, P. J., Reed, H. C., and Heath, R. R. "An Alarm Pheromone from Heads of Worker Vespula squamosa (Hymenoptera: Vespidae)", "Florida Entomologist", June 1999.</ref> In ''[[Polistes exclamans]]'', alarm pheromones are also used as an alert to incoming predators.<ref>{{cite journal | vauthors = Post DC, Downing HA, Jeanne RL | title = Alarm response to venom by social waspsPolistes exclamans andP. fuscatus (Hymenoptera: Vespidae) | journal = Journal of Chemical Ecology | volume = 10 | issue = 10 | pages = 1425–1433 | date = October 1984 | pmid = 24318343 | doi = 10.1007/BF00990313 | bibcode = 1984JCEco..10.1425P | s2cid = 38398672 }}</ref> Pheromones also exist in plants: Certain plants emit alarm pheromones when grazed upon, resulting in [[tannin]] production in neighboring plants.<ref name=":1">{{Cite book| vauthors = Marcus JB |url=https://www.worldcat.org/oclc/1097958893|title=Aging, nutrition and taste nutrition, food science and culinary perspectives for aging tastefully|date=2019|publisher=Elsevier Academic Press |isbn=978-0-12-813528-0|location=[Place of publication not identified]|oclc=1097958893}}</ref> These tannins make the plants less appetizing to [[herbivore]]s.<ref name=":1" />

An alarm pheromone has been documented in a mammalian species. Alarmed [[pronghorn]], ''Antilocapra americana'' flair their white rump hair and exposes two highly odoriferous glands that releases a compound described having the odor "reminiscent of buttered popcorn". This sends a message to other pronghorns by both sight and smell about a present danger. This scent has been observed by humans 20 to 30 meters downwind from alarmed animals. The major odour compound identified from this gland is [[2-pyrrolidinone]].<ref>{{cite journal | last1 = Wood | first1 = William F. | year = 2002 | title = 2-Pyrrolidinone, a putative alerting pheromone from rump glands of pronghorn, Antilocapra Americana | journal = Biochemical Systematics and Ecology | volume = 30 | issue = 4 | pages = 361–363 | doi=10.1016/S0305-1978(01)00097-7| bibcode = 2002BioSE..30..361W }}</ref>

===Epideictic===
Epideictic pheromones are different from territory pheromones, when it comes to insects. [[Jean Henri Fabre|Fabre]] observed and noted how "females who lay their eggs in these fruits deposit these mysterious substances in the vicinity of their clutch to signal to other females of the same species they should clutch elsewhere." It may be helpful to note that the word [[epideictic]], having to do with display or show (from the Greek 'deixis'), has a different but related meaning in rhetoric, the human art of persuasion by means of words.

===Territorial===
[[File:Urinating dog (7768361246).jpg|thumb|[[Dog communication|Dogs communicate]] using pheromones and [[olfactic communication|olfactory signals]] in [[urine]].<ref>{{Cite book |last=Miklósi |first=Ádám |url=https://books.google.com/books?id=_6BIDwAAQBAJ&pg=PA110 |title=The Dog: A Natural History |date=2018-04-03 |publisher=Princeton University Press |isbn=978-1-4008-8999-0 |language=en}}</ref>]]
Laid down in the environment, territorial pheromones mark the boundaries and identity of an organism's territory. Cats and dogs deposit these pheromones by [[spraying (animal behavior)|urinating on landmarks]] that mark the perimeter of the claimed territory. In social seabirds, the preen gland is used to mark nests, nuptial gifts, and territory boundaries with behavior formerly described as '[[displacement activity]]'.<ref name="users.rcn.com"/>

===Trail===
{{Main|Trail pheromone}}
Social insects commonly use trail pheromones. For example, [[ant]]s mark their paths with pheromones consisting of volatile [[hydrocarbon]]s. Certain ants lay down an initial trail of pheromones as they return to the nest with food. This trail attracts other ants and serves as a guide.<ref>{{cite web |url= http://www.news.cornell.edu/releases/Feb98/antpheromone.hrs.html | title= Excited ants follow pheromone trail of same chemical they will use to paralyze their prey | access-date= 2006-03-14}}</ref> As long as the food source remains available, visiting ants will continuously renew the pheromone trail. The pheromone requires continuous renewal because it evaporates quickly. When the food supply begins to dwindle, the trail-making ceases. Pharaoh ants (''[[Monomorium pharaonis]]'') mark trails that no longer lead to food with a repellent pheromone, which causes avoidance behaviour in ants.<ref>{{cite journal | vauthors = Robinson EJ, Green KE, Jenner EA, Holcombe M, Ratnieks FL | title = Decay rates of attractive and repellent pheromones in an ant foraging trail network. | journal = Insectes Sociaux | date = 2008 | volume = 55 | issue = 3 | pages = 246–251  | doi = 10.1007/s00040-008-0994-5 | s2cid = 27760894 | url = http://eprints.whiterose.ac.uk/46214/1/RobinsonPheromoneDecayInsSoc.pdf }}</ref>
Repellent trail markers may help ants to undertake more efficient collective exploration.<ref>
{{cite journal | vauthors = Hunt ER, Franks NR, Baddeley RJ | title = The Bayesian superorganism: externalized memories facilitate distributed sampling | journal = Journal of the Royal Society, Interface | volume = 17 | issue = 167 | pages = 20190848 | date = June 2020 | pmid = 32546115 | pmc = 7328406 | doi = 10.1098/rsif.2019.0848 | doi-access = free }}</ref> 
The army ant ''[[Eciton burchellii]]'' provides an example of using pheromones to mark and maintain foraging paths. When species of wasps such as ''[[Polybia sericea]]'' found new nests, they use pheromones to lead the rest of the colony to the new nesting site.

Gregarious caterpillars, such as the [[Forest tent caterpillar moth|forest tent caterpillar]], lay down pheromone trails that are used to achieve group movement.<ref>{{cite journal | vauthors = Fitzgerald TD | title = Use of pheromone mimic to cause the disintegration and collapse of colonies of tent caterpillars ( Malacosoma spp.). | journal = Journal of Applied Entomology | date = July 2008 | volume = 132 | issue = 6 | pages = 451–460 | doi = 10.1111/j.1439-0418.2008.01286.x | s2cid = 83824574 }}
</ref>

===Sex===
{{main|Sex pheromone}}
[[File:Danaus chrysippus male by kadavoor.JPG|right|thumb|Male ''Danaus chrysippus'' showing the pheromone pouch and brush-like organ in [[Kerala, India]]]]
In animals, sex pheromones indicate the availability of the female for breeding. Male animals may also emit pheromones that convey information about their species and [[genotype]].

At the microscopic level, a number of bacterial species (e.g. ''[[Bacillus subtilis]]'', ''[[Streptococcus pneumoniae]]'', ''[[Bacillus cereus]]'') release specific chemicals into the surrounding media to induce the "competent" state in neighboring bacteria.<ref>{{cite journal | vauthors = Bernstein C, Bernstein H | title = Sexual communication | journal = Journal of Theoretical Biology | volume = 188 | issue = 1 | pages = 69–78 | date = September 1997 | pmid = 9299310 | doi = 10.1006/jtbi.1997.0459 | bibcode = 1997JThBi.188...69B }}</ref> [[Natural competence|Competence]] is a physiological state that allows bacterial cells to take up DNA from other cells and incorporate this DNA into their own genome, a sexual process called transformation.

Among eukaryotic microorganisms, pheromones promote sexual interaction in numerous species.<ref>Danton H. O’Day, Paul A. Horgen (1981) Sexual Interactions in Eukaryotic Microbes Academic Press, New York. {{ISBN|0125241607}} {{ISBN|978-0125241601}}</ref> These species include the yeast ''[[Saccharomyces cerevisiae]]'', the filamentous fungi ''[[Neurospora crassa]]'' and [[Mucor mucedo]], the water mold ''[[Achlya ambisexualis]]'', the aquatic fungus ''[[Allomyces macrogynus]]'', the slime mold ''[[Dictyostelium discoideum]]'', the ciliate protozoan ''[[Blepharisma japonicum]]'' and the multicellular green algae ''[[Volvox carteri]]''. In addition, male [[copepod]]s can follow a [[three-dimensional]] pheromone trail left by a swimming female, and male [[gamete]]s of many animals use a pheromone to help find a female gamete for [[fertilization]].<ref>Dusenbery, David B. (2009). ''Living at Micro Scale'', Chapters 19 & 20. Harvard University Press, Cambridge, Massachusetts {{ISBN|978-0-674-03116-6}}.</ref>

Many well-studied insect species, such as the ant ''[[Leptothorax acervorum]]'', the moths ''[[Helicoverpa zea]]'' and ''[[Agrotis ipsilon]]'', the bee ''[[Xylocopa sonorina]],''  the frog [[Bibron's toadlet|Pseudophryne bibronii]], and the butterfly [[Edith's checkerspot]] release sex pheromones to attract a mate, and some [[lepidoptera]]ns (moths and butterflies) can detect a potential mate from as far away as {{convert|10|km|mi|abbr=on}}.<ref>{{cite journal | vauthors = Raina AK, Klun JA | title = Brain factor control of sex pheromone production in the female corn earworm moth | journal = Science | volume = 225 | issue = 4661 | pages = 531–533 | date = August 1984 | pmid = 17750856 | doi = 10.1126/science.225.4661.531 | s2cid = 40949867 | bibcode = 1984Sci...225..531R }}</ref><ref name="XiangYang2009">{{cite journal | vauthors = Xiang Y, Yang M, Li Z |title=Calling behavior and rhythms of sex pheromone production in the Black Cutworm Moth in China|journal=Journal of Insect Behavior |volume=23 |issue=1 |year=2009 |pages=35–44 |doi=10.1007/s10905-009-9193-0|s2cid=45577568 }}</ref> Some insects, such as [[ghost moth]]s, use pheromones during [[lek mating]].<ref>{{cite journal | vauthors = Schulz S, Francke W, König WA, Schurig V, Mori K, Kittmann R, Schneider D | title = Male pheromone of swift moth, Hepialus hecta L. (Lepidoptera: Hepialidae) | journal = Journal of Chemical Ecology | volume = 16 | issue = 12 | pages = 3511–3521 | date = December 1990 | pmid = 24263445 | doi = 10.1007/BF00982114 | bibcode = 1990JCEco..16.3511S | s2cid = 26903035 }}</ref> Traps containing pheromones are used by farmers to detect and monitor insect populations in orchards. In addition, ''[[Colias eurytheme]] ''butterflies release pheromones, an olfactory cue important for mate selection.<ref>{{cite journal | vauthors = Papke RS, Kemp DJ, Rutowski RL | year = 2007 | title = Multimodal Signalling: Structural Ultraviolet Reflectance Predicts Male Mating Success Better than Pheromones in the Butterfly Colias eurytheme L. (Pieridae) | journal = Animal Behaviour | volume = 73 | pages = 47–54 | doi=10.1016/j.anbehav.2006.07.004| s2cid = 40403665 }}</ref> In mealworm beetles, ''[[Mealworm|Tenebrio molitor]],'' the female preference of pheromones is dependent on the nutritional condition of the males.  

The effect of Hz-2V virus infection on the reproductive physiology and behavior of female ''[[Helicoverpa zea]]'' moths is that in the absence of males they exhibited calling behavior and called as often but for shorter periods on average than control females. Even after these contacts virus-infected females made many frequent contacts with males and continued to call; they were found to produce five to seven times more pheromone and attracted twice as many males as did control females in flight tunnel experiments.<ref>{{cite journal | vauthors = Burand JP, Tan W, Kim W, Nojima S, Roelofs W | title = Infection with the insect virus Hz-2v alters mating behavior and pheromone production in female Helicoverpa zea moths | journal = Journal of Insect Science | volume = 5 | pages = 6 | year = 2005 | pmid = 16299596 | pmc = 1283887 | doi = 10.1093/jis/5.1.6 }}</ref>

Pheromones are also utilized by bee and wasp species. Some pheromones can be used to suppress the sexual behavior of other individuals allowing for a reproductive monopoly – the wasp ''[[Ropalidia marginata|R. marginata]] ''uses this.<ref>{{Cite journal|title = Natural history and behaviour of the primitively eusocial wasp (Hymenoptera: Vespidae): a comparison of the two sexes| vauthors = Sen R, Gadagkar R |date = 2010|journal = Journal of Natural History|volume = 44|issue = 15–16|pages = 959–968|doi = 10.1080/00222931003615703|s2cid = 84698285}}</ref> With regard to the ''[[Bombus hyperboreus]]'' species, males, otherwise known as drones, patrol circuits of scent marks (pheromones) to find queens.<ref>"Alpinobombus". ''Natural History Museum''. Retrieved 26 September 2015</ref> In particular, pheromones for the ''Bombus hyperboreus,'' include [[Oleyl alcohol|octadecenol]], 2,3-dihydro-6-transfarnesol, citronellol, and geranylcitronellol.<ref>{{cite journal | vauthors = Svensson BG, Bergstrom G | year = 1979 | title = Marking Pheromones of Alpinobornbus Males | doi = 10.1007/bf00987845 | journal = Journal of Chemical Ecology | volume = 5 | issue = 4 | pages=603–615| bibcode = 1979JCEco...5..603S | s2cid = 20759942 }}</ref>

[[Sea urchin]]s release pheromones into the surrounding water, sending a chemical message that triggers other urchins in the colony to eject their sex cells simultaneously.

In plants, some homosporous ferns release a chemical called [[antheridiogen]], which affects sex expression. This is very similar to pheromones.

===Other===
This classification, based on the effects on behavior, remains artificial. Pheromones fill many additional functions.
* [[Nasonov pheromone]]s (worker bees)
* Royal pheromones (bees)
* Calming (appeasement) pheromones (mammals)
* Necromones, given off by a deceased and decomposing organism; consisting of [[oleic acid|oleic]] and [[linoleic acid]]s, they allow crustaceans and hexapods to identify the presence of dead [[Conspecificity|conspecifics]].<ref>{{Cite journal | vauthors = Yao M, Rosenfeld J, Attridge S, Sidhu S, Aksenov V, Rollo CD | title = The Ancient Chemistry of Avoiding Risks of Predation and Disease | journal = Evolutionary Biology | volume = 36 | issue = 3 | pages = 267–281 | issn = 0071-3260 | doi = 10.1007/s11692-009-9069-4 | year = 2009 | bibcode = 2009EvBio..36..267Y | s2cid = 29901266 }}</ref>
* Suckling: [[tert-Amyl alcohol|TAA]] is present in rabbit milk and seems to play a role of pheromone inducing suckling in the newborn rabbit.<ref>{{cite journal | vauthors = Schaal B, Coureaud G, Langlois D, Giniès C, Sémon E, Perrier G | title = Chemical and behavioural characterization of the rabbit mammary pheromone | journal = Nature | volume = 424 | issue = 6944 | pages = 68–72 | date = July 2003 | pmid = 12840760 | doi = 10.1038/nature01739 | s2cid = 4428155 | bibcode = 2003Natur.424...68S }}</ref>