Editing Pheromone (section)

===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.