Editing Parasitism (section)

=== Modifying host behaviour ===

{{further|Behavior-altering parasites}}
<!--
[[File:Reclinervellus nielseni.jpg|thumb|left|A larva of ''[[Reclinervellus nielseni]]'' parasitizing ''[[Cyclosa argenteoalba]]'' in Japan]]-->

Some parasites [[Behavior-altering parasites|modify host behaviour]] in order to increase their transmission between hosts, often in relation to predator and prey ([[parasite increased trophic transmission]]). For example, in the [[California coastal salt marsh]], the fluke ''[[Euhaplorchis californiensis]]'' reduces the ability of its [[killifish]] host to avoid predators.<ref>{{cite journal |last1=Lafferty |first1=K. D. |last2=Morris |first2=A. K. |year=1996 |url=http://parasitology.msi.ucsb.edu/sites/parasitology.msi.ucsb.edu/files/docs/publications/Altered%20Behavior.pdf |archive-url=https://web.archive.org/web/20190303123301/http://parasitology.msi.ucsb.edu/sites/parasitology.msi.ucsb.edu/files/docs/publications/Altered%20Behavior.pdf |archive-date=3 March 2019 |url-status=live |title=Altered behavior of parasitized killifish increases susceptibility to predation by bird final hosts |journal=Ecology |volume=77 |issue=5 |pages=1390–1397 |doi=10.2307/2265536 |jstor=2265536 |bibcode=1996Ecol...77.1390L }}</ref> This parasite matures in [[egret]]s, which are more likely to feed on infected killifish than on uninfected fish. Another example is the protozoan ''[[Toxoplasma gondii]]'', a parasite that matures in [[Felis silvestris catus|cats]] but can be carried by many other [[Mammalia|mammals]]. Uninfected [[Rattus rattus|rats]] avoid cat odors, but rats infected with ''T. gondii'' are drawn to this scent, which may increase transmission to feline hosts.<ref>{{cite journal |last1=Berdoy |first1=M. |last2=Webster |first2=J. P. |last3=Macdonald |first3=D. W. |title=Fatal attraction in rats infected with ''Toxoplasma gondii'' |journal=Proc. Biol. Sci. |volume=267 |issue=1452 |pages=1591–4 |year=2000 |pmid=11007336 |pmc=1690701 |doi=10.1098/rspb.2000.1182 }}</ref> The malaria parasite modifies the skin odour of its human hosts, increasing their attractiveness to mosquitoes and hence improving the chance for the parasite to be transmitted.<ref name="de Boer2017"/> The spider ''[[Cyclosa argenteoalba]]'' often have parasitoid wasp larvae attached to them which alter their web-building behavior. Instead of producing their normal sticky spiral shaped webs, they made simplified webs when the parasites were attached. This manipulated behavior lasted longer and was more prominent the longer the parasites were left on the spiders.<ref>{{cite journal |last=Takasuka |first=Keizo |date=16 September 2019 |title=Evaluation of manipulative effects by an ichneumonid spider-ectoparasitoid larva upon an orb-weaving spider host (Araneidae: Cyclosa argenteoalba) by means of surgical removal and transplantation |url=http://dx.doi.org/10.1636/joa-s-18-082 |journal=The Journal of Arachnology |volume=47 |issue=2 |page=181 |doi=10.1636/joa-s-18-082|s2cid=202579182 |issn=0161-8202}}</ref>

[[File:Bed bug, Cimex lectularius.jpg|thumb|Trait loss: bedbug ''[[Cimex lectularius]]'' is flightless, like many insect ectoparasites.]]