View source for Pyemotes herfsi

{{Short description|Species of mite}}
{{Italic title}}
{{Taxobox
| name = ''Pyemotes herfsi''
| image = Pyemotes herfsi_2.jpg
| regnum = [[Animal]]ia
| phylum = [[Arthropod]]a
| classis = [[Arachnid]]a
| subclassis = [[Acari]]
| ordo = [[Trombidiformes]]
| familia = [[Pyemotidae]]
| genus = ''[[Pyemotes]]''
| species = '''''P. herfsi'''''
| binomial = ''Pyemotes herfsi''
| binomial_authority = ([[Anthonie Cornelis Oudemans|Oudemans]], 1936)
}}

'''''Pyemotes herfsi''''', also known as the '''oak leaf gall mite''' or '''itch mite''', is an [[parasitism|ectoparasitic]] [[mite]] identified in Europe and subsequently found in India, Asia, and the United States. The mite parasitizes a variety of insect hosts and bites humans, causing red, itchy, and painful [[wikt:wheal|wheal]]s (welts). The mites are barely visible, measuring about 0.2–0.8 millimeters; their great reproductive potential, small size, and high capacity for dispersal by wind make them difficult to control or avoid.<ref name=usda>Multiple sources:
*{{cite web|title=Pyemotes herfsi (Acari: Pyemotidae), a Mite New to North America as the Cause of Bite Outbreaks|url=http://ddr.nal.usda.gov/bitstream/10113/3600/1/IND43948382.pdf|publisher=[[USDA]]|accessdate=2010-04-25|url-status=dead|archiveurl=https://web.archive.org/web/20110721072019/http://ddr.nal.usda.gov/bitstream/10113/3600/1/IND43948382.pdf|archivedate=2011-07-21}}
* {{cite web|last=Cloyd|date=November 3, 2016|first=Raymond|url=https://blogs.k-state.edu/kansasbugs/2016/11/03/oak-leaf-itch-mite/|title=Oak Leaf Itch Mite|work=Extension Entomology|location=[[Manhattan, Kansas]]|publisher=[[Kansas State University]] Department of Entomology|access-date=January 27, 2024|archive-url=https://web.archive.org/web/20200814061543/https://blogs.k-state.edu/kansasbugs/2016/11/03/oak-leaf-itch-mite/|archive-date=August 14, 2020|url-status=live}}</ref>

==Life cycle==
Newly emerged and mated females inject a [[neurotoxin]]-containing saliva into their hosts, which paralyzes the host and enables the [[gravid]] female mites to feed on the host's [[hemolymph]].<ref name=usda/> The posterior portion (opisthosoma) of the female enlarges as its progeny develops inside, and, within a few days, up to 250 adult mites emerge from the gravid female.<ref name=usda/> Bruce and Wrensch (1990) found that progeny of the straw itch mite averaged 254 offspring of which 92% were females. Males emerge before the females, position themselves around the mother's genital opening, and mate with emerging females.<ref name=usda/> Then, mated females disperse to find new hosts.<ref name=usda/> These mites often are dispersed by wind, and when they land on vertebrate hosts, they attempt to feed, resulting in the bites.<ref name=usda/> A life cycle can be completed within seven days, and progeny emergence can be extended to 15 days.<ref name=usda/>

The mites' reported hosts have included ''[[Anobium punctatum]]'', the [[pink bollworm]], ''[[Grapholita molesta]]'', ''[[Tineola bisselliella]]'', ''[[Apis cerana]]'' (Asiatic honey bee), [[periodical cicada]]s, and various pests of stored grain, as well as humans and their pets.<ref name=Broce>{{cite journal|date=May 2006|last1=Broce|first1=Alberto B.|last2=Zurek|first2=Ludek|last3=Kalisch|first3=James A.|last4=Brown|first4=Robert|display-authors=3|url=https://www.srs.fs.usda.gov/pubs/ja/ja_moser050.pdf|title=Pyemotes herfsi (Acari: Pyemotidae), a Mite New to North America as the Cause of Bite Outbreaks|journal=[[Journal of Medical Entomology]]|volume=43|number=3|pages=610–613|doi=10.1093/jmedent/43.3.610 |doi-access=free|pmid=16739423|access-date=March 11, 2024|archive-url=https://web.archive.org/web/20240127224629/https://www.srs.fs.usda.gov/pubs/ja/ja_moser050.pdf|archive-date=January 27, 2024|url-status=live}}</ref><ref>Multiple sources:
* {{cite book|title=Bibliography of Commonwealth Apiculture|author=Richard Jones|publisher=[[Commonwealth Secretariat]]|year=2005|page=104|isbn=978-0-85092-771-9}}
* {{cite web|title=Pests that affect human health – Oak leaf Itch Mite|url=http://www.ksre.ksu.edu/library/entml2/mf2806.pdf|publisher=[[Kansas State University]]|accessdate=2010-04-25|url-status=dead|archiveurl=https://web.archive.org/web/20110716115233/http://www.ksre.ksu.edu/library/entml2/mf2806.pdf|archivedate=2011-07-16}}</ref> Their usual hosts in the United States are oak [[gall midge|midge]] larvae.<ref name="Broce" /> Cooler, more moist conditions favor its population growth. Outbreaks of attacks on humans in the United States have been attributed to fluctuations in the supply of both [[oak]] midge [[larva]]e and periodical cicada eggs.<ref name=usda/><ref name=cicada>Multiple sources:
* {{cite journal|last=Zaborski|first=Edmond R.|date=May 20, 2008|url=https://www.ideals.illinois.edu/items/18258|title=2007 Outbreak of Human Pruritic Dermatitis in Chicago, Illinois Caused by an Itch Mite, Pyemotes herfsi (Oudemans, 1936) (Acarina: Heterostigmata: Pyemotidae|journal=Illinois Natural History Survey Technical Report|id=NHS Technical Report 2008 (17)|location=[[Champaign, Illinois]]|publisher=[[Illinois Natural History Survey]]|access-date=January 28, 2024|archive-url=https://web.archive.org/web/20240128154210/https://www.ideals.illinois.edu/items/18258|archive-date=January 28, 2024|url-status=live}}
* {{cite web|date=May 20, 2008|last=Zaborski|first=Edmond R.|url=http://www.idph.state.il.us/envhealth/pcitchmites_update5-23-08.htm|title=Itch Mite Update: Conclusions from "2007 Outbreak of Human Pruritic Dermatitis in Chicago, Illinois Caused by an Itch Mite, Pyemotes herfsi": Illinois Natural History Survey Technical Report 2008 (17)|location=[[Springfield, Illinois]]|publisher=[[Illinois Department of Public Health]]|access-date=January 27, 2024|archive-url=https://web.archive.org/web/20220713193034/http://www.idph.state.il.us/envhealth/pcitchmites_update5-23-08.htm|archive-date=July 13, 2022|url-status=live}}
* {{cite news|last=Wilder|first=Drew|date=July 30, 2021|url=https://www.nbcwashington.com/news/local/northern-virginia/mysterious-nasty-bug-bites-stump-arlington-health-officials/2751051/|title=Mysterious, Nasty Bug Bites Stump Arlington Health Officials|work=[[WRC-TV|NBC4 Washington]]|location=Washington, D.C.|access-date=March 10, 2024|archive-url=https://web.archive.org/web/20231209041755/https://www.nbcwashington.com/news/local/northern-virginia/mysterious-nasty-bug-bites-stump-arlington-health-officials/2751051/|archive-date=December 9, 2023|url-status=live}} Contains 1:38 minute video showing images and descriptions of ''Pyemotes herfsi'' bites.
* {{cite news|date=July 30, 2021|last=Silverman|first=Ellie|url=https://www.washingtonpost.com/dc-md-va/2021/07/30/oak-mites-bite-cicadas-dc/|title=Oak-mite bites: Cicadas may have left D.C. region an itchy gift|newspaper=[[The Washington Post]]|location=Washington, D.C.|access-date=January 27, 2024}}
* {{cite web|date=August 13, 2021|last=Shrewsbury|first=Paula|url=https://extension.umd.edu/resource/oak-leaf-itch-mites-and-periodical-cicada-eggs/|title=Oak Leaf Itch Mites and Periodical Cicada Eggs|work=[[University of Maryland College of Agriculture and Natural Resources#University of Maryland Extension|University of Maryland Extension]]|publisher=[[University of Maryland College of Agriculture and Natural Resources]]|access-date=January 27, 2024|archive-url=https://web.archive.org/web/20230604234309/https://extension.umd.edu/resource/oak-leaf-itch-mites-and-periodical-cicada-eggs/|archive-date=June 4, 2023|url-status=live}}</ref>

==Distribution==
''P. herfsi'' has been recorded in [[Czechoslovakia]],<ref>{{cite journal |vauthors=Samsinák K, Chmela J, Vobrázková E |title=Pyemotes herfsi (Oudemans, 1936) as causative agent of another mass dermatitis in Europe (Acari, Pyemotidae) |journal=Folia Parasitol. |volume=26 |issue=1 |pages=51–4 |year=1979 |pmid=156143 }}</ref> [[Egypt]],<ref>[http://www.ars.usda.gov/is/np/pinkbollworm/pinkbollworm.pdf USDA. A Bibliography of the Pink Bollworm]</ref> [[Australia]],<ref>[http://agspsrv34.agric.wa.gov.au/ento/staff4.htm Department of Agriculture and Food, Western Australia] {{webarchive|url=http://webarchive.loc.gov/all/20090609121749/http://agspsrv34.agric.wa.gov.au/ento/staff4.htm |date=2009-06-09 }}</ref> northern [[India]],<ref>[http://www.ias.ac.in/j_archive/currsci/53/1/53-54/viewpage.html Proceedings of the Indian Academy of Sciences]</ref> and the United States. It is a regulated pest in [[Germany]].<ref>[http://www.bba.bund.de/nn_1030794/SharedDocs/07__AG/Publikationen/internat/nz/nz3-seeds-avena-et.pdf,templateId=raw,property=publicationFile.pdf/nz3-seeds-avena-et.pdf  Biologische Bundesanstalt für Land- und Forstwirtschaft]</ref>

==Impact on humans==
[[File:Bite of Pyemotes herfsi.jpg|thumb|right|250px|Itch mite bites]] Rashes resulting from the bite of ''P.&nbsp;herfsi'' were first documented in Europe in 1936. The first documented outbreak in the US is thought to have occurred in 2004 in [[Kansas City, Kansas]].<ref>{{Cite journal |last=Broce |first=Alberto B |date=May 2006 |title=Pyemotes herfsi (Acari: Pyemotidae), a mite new to North America as the cause of bite outbreaks |url=https://www.srs.fs.usda.gov/pubs/ja/ja_moser050.pdf |journal=Journal of Medical Entomology |volume=43 |issue=3 |pages=610–613 |pmid=16739423 |doi=10.1603/0022-2585(2006)43[610:phapam]2.0.co;2}}</ref> The closely related straw itch mite (''[[Pyemotes tritici]]'') was initially suspected, but no specimens of this species were found. The reports indicated that the bites occurred on people after being outdoors in or near wooded areas. Based on this information, a search was initiated and resulted in the discovery of ''Pyemotes herfsi'' preying on midge larvae in leaf galls on [[pin oak]] trees.

The United States [[Centers for Disease Control]] estimated that during an outbreak in August 2004, 54% of the population of [[Crawford County, Kansas]], or about 19,000 people, suffered from its bites.<ref name=mm5438a3>* {{cite journal|author=Centers for Disease Control and Prevention (CDC)|author-link=Centers for Disease Control and Prevention|date=September 2005|url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5438a3.htm|title=Outbreak of pruritic rashes associated with mites – Kansas, 2004|journal=Morbidity and Mortality Weekly Report (MMDR Weekly)|volume=54 |issue=38 |pages=952–955 |location=[[Atlanta]], [[Georgia (U.S. state)|Georgia]]|pmid=16195693|access-date=March 11, 2024|archive-url=https://web.archive.org/web/20231129101520/https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5438a3.htm|archive-date=November 29, 2023|url-status=live}}</ref> Other states in the U.S, where humans have been affected during the 2000s are [[Nebraska]], [[Oklahoma]], [[Missouri]], [[Tennessee Shelby County]], [[Texas]], and [[Illinois]].<ref name=Keith>{{cite news|last1=Keith|first1=David|last2=Karstens|first2=Sandi Alswager|date=May 2, 2005|url=http://ianrnews.unl.edu/static/0505021.shtml|title=Itch Mites Are Back, Entomologist Warns|work=IANR News Story|location=[[Lincoln, Nebraska]]|publisher=[[University of Nebraska–Lincoln#Colleges|University of Nebraska - Lincoln: Institute of Agriculture and Natural Resources]]|archive-url=https://web.archive.org/web/20070816073516/http://ianrnews.unl.edu/static/0505021.shtml|archive-date=August 16, 2007|url-status=dead}}</ref><ref>[http://www.chicagotribune.com/news/local/chicago/chi-bugbitesaug14,0,2767759.story?coll=chi-news-hed Chicago Tribune, August 14, 2007]</ref> In August 2008 an outbreak was reported in the northern suburbs of [[Cincinnati, Ohio]] by the [[Hamilton County, Ohio|Hamilton County]] Public Health Department.<ref>[http://www.wlwt.com/health/17299642/detail.html?rss=cin&psp=news WLWT TV, Cincinnati, Ohio, August 26, 2008]</ref>

Many reports of itch mite bites on people's necks, shoulders and chests appeared in the [[Washington metropolitan area]] in July 2021 after an [[Brood X#2021 emergence|emergence of Brood X]] of the periodical cicada had ended. Experts attributed the bites to ''P.&nbsp;herfsi'', as a report of an outbreak of bite rashes around Chicago, Illinois, during August and September 2007 had stated that the developing eggs of periodical cicadas were the only insects that the mites had parasitized in the field at the time. After emerging earlier in the year, the cicadas had laid large numbers of eggs in the terminal branches of many of the area's [[Deciduous|deciduous trees]].<ref name=cicada/>

Humans typically report itching from mite bites within 10 to 16 hours after contact. The victims often do not recall being bitten. The rash that results from the bites is usually described as a red patch with a small blister in the center, most often found on the neck, face, arms, or upper torso. A secondary bacterial infection sometimes arises when the bite is scratched. The suggested treatments include the application of [[calamine]] lotion, an [[antihistamine]] cream such as [[diphenhydramine]], or a [[topical steroid]] cream; a suggested preventive measure is the application of [[DEET]] before outdoor activity.<ref name=Keith/> Anecdotal reports from the Kansas outbreak, however, suggest that DEET might not provide complete protection against ''P.&nbsp;herfsi''.<ref name=mm5438a3/><ref>{{cite journal |title=Outbreak of pruritic rashes associated with mites – Kansas, 2004 |journal=MMWR Morb Mortal Wkly Rep |volume=54 |issue=38 |pages=952–5 |date=September 2005 |pmid=16195693 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/mm5438a3.htm |author1= Centers for Disease Control and Prevention (CDC)}}</ref>

The bites are not life-threatening, but a few individuals suffering 100 or more bites have undergone brief hospitalizations.<ref name=Keith/><ref>{{cite news|last1=Keith|first1=David|last2=Moser|first2=Dan|date=July 15, 2005|url=http://ianrnews.unl.edu/static/0507150.shtml|title=Itch Mite Population About to Increase, Entomologist Warns|work=IANR News Story|location=[[Lincoln, Nebraska]]|publisher=[[University of Nebraska–Lincoln#Colleges|University of Nebraska - Lincoln: Institute of Agriculture and Natural Resources]]|archive-url=https://web.archive.org/web/20060509131236/http://ianrnews.unl.edu/static/0507150.shtml|archive-date=May 9, 2006|url-status=dead}}</ref>

==References==
*''This article utilizes text taken verbatim from ''Pyemotes herfsi (Acari: Pyemotidae), a Mite New to North America as the Cause of Bite Outbreaks'', a [[public domain]] publication of the [[United States Department of Agriculture]].''
{{Reflist|2}}

==External links==
*[https://archive.today/20060901192318/http://mail.pittstate.edu/~dgordon/MysteryBites/MysteryBites.html Photographs of P. herfsi bites on humans. Pittsburg State University, Pittsburg, Kansas. April 18, 2007]
*[https://web.archive.org/web/20120216000854/http://www.oznet.ksu.edu/library/entml2/mf2806.pdf Oak Leaf Itch Mite, Alberto Broce, James Kalisch, Kansas State University, October 2007, 2 p., illustrated]

{{Mite-related diseases and infestations}}
{{Taxonbar|from=Q7262965}}

[[Category:Arachnids of Europe]]
[[Category:Trombidiformes]]
[[Category:Animals described in 1936]]
[[Category:Taxa named by Anthonie Cornelis Oudemans]]