Editing Citrus (section)

=== Pests and diseases ===

{{main list|List of citrus diseases}}

Among the diseases of citrus plantations are [[citrus black spot]] (a fungus), [[citrus canker]] (a bacterium), [[citrus greening]] (a bacterium, spread by an insect pest), and sweet orange scab (a fungus, ''Elsinöe australis'').<ref name="USDA 2024">{{cite web |title=Citrus diseases |url=https://www.aphis.usda.gov/plant-pests-diseases/citrus-diseases |website=U. S. Department of Agriculture Animal and Plant Health Inspection Service |access-date=20 October 2024 |date=22 August 2024}}</ref> Citrus plants are liable to infestation by [[ectoparasite]]s which act as [[Vector (epidemiology)|vectors]] to plant diseases: for example, aphids transmit the damaging [[citrus tristeza virus]],<ref>{{cite journal |last1=Lee |first1=Richard F. |title=Chapter Five - Control of Virus Diseases of Citrus |journal=Advances in Virus Research |date=2015 |volume=92 |pages=143–173 |doi=10.1016/bs.aivir.2014.10.002 |pmid=25591879 }}</ref> while the aphid-like [[Diaphorina citri|Asian citrus psyllid]] can carry the bacterium which causes the serious [[citrus greening disease]].<ref name="Alquezar-et-al-2021">{{cite journal |last1=Alquézar |first1=Berta |last2=Carmona |first2=Lourdes |last3=Bennici |first3=Stefania |last4=Peña |first4=Leandro |title=Engineering of citrus to obtain huanglongbing resistance |journal=[[Current Opinion in Biotechnology]] |publisher=[[Elsevier]] |volume=70 |year=2021 |doi=10.1016/j.copbio.2021.06.003 |pages=196–203 |s2cid=235712334 |pmid=34198205|doi-access=free |hdl=10251/189663 |hdl-access=free }}</ref><ref name="californiacitrusthreat">{{cite web |url=http://www.californiacitrusthreat.org/asian-citrus-psyllid.php |title=About the Asian Citrus Psyllid and Huanglongbing |work=californiacitrusthreat.org |access-date=30 November 2012 |archive-date=13 December 2012 |archive-url=https://web.archive.org/web/20121213014128/http://www.californiacitrusthreat.org/asian-citrus-psyllid.php |url-status=dead}}</ref> This threatens production in Florida,<ref>{{Cite web |url=https://www.nass.usda.gov/Statistics_by_State/Florida/Publications/Citrus/Citrus_Statistics/2015-16/fcs1516.pdf |title=Florida Citrus Statistics 2015–2016 |date=3 October 2017 |website=United States Department of Agriculture – National Agricultural Statistics Service|access-date=3 October 2017 |pages=62 |quote=Abandoned groves are a threat to the citrus industry and are a haven for psyllids carrying the bacterium that causes greening disease.}}</ref><ref>{{cite news |last=Nelson |first=Diane|title=Can Science Save Citrus? Farmers, researchers try to hold off deadly citrus greening long enough to find cure |date=27 August 2019 |url=https://www.ucdavis.edu/food/news/can-science-solve-citrus-greening-disease/ |access-date=20 September 2019}}</ref> California,<ref name="californiacitrusthreat"/> and worldwide. Citrus groves are attacked by parasitic [[Nematode]]s including citrus (''[[Tylenchulus semipenetrans]]'') and sheath nematodes (''[[Hemicycliophora]]'' spp.).<ref>{{Cite web |title=Nematodes / Citrus / Agriculture: Pest Management Guidelines / UC Statewide IPM Program |url=https://ipm.ucanr.edu/agriculture/citrus/nematodes/#gsc.tab=0 |access-date=2024-11-14 |website=ipm.ucanr.edu}}</ref><ref>A Sheath Nematode, Hemicycliophora arenaria raski, Pathogenic to Citrus, by D. E. Stokes, Florida Department of Agriculture and Consumer Services, July 1977[https://ccmedia.fdacs.gov/content/download/10832/file/nem029.pdf]</ref>

<gallery mode=packed>
File:Citrus Black Spot on Valencia orange (detail).jpg|[[Citrus black spot]] on a [[Valencia orange]]
File:CTV Leaf Chlorosis.jpg|[[Chlorosis]] caused by [[Citrus tristeza virus]]
File:Citrus canker on fruit.jpg|[[Citrus canker]], caused by the [[gammaproteobacterium]] ''Xanthomonas axonopodis''
File:Asian Citrus Psyllid adult (detail).jpg|[[Asian citrus psyllid]], [[Disease vector|vector]] of citrus greening disease
File:Huanglongbing (cropped).jpg|[[Citrus greening disease]] on [[mandarin orange]]
File:Life stages of citrus nematode.svg|Life stages of the citrus [[nematode]],''[[Tylenchulus semipenetrans]]''
</gallery>