{{Short description|Species of pseudoscorpion}} {{use dmy dates |date=October 2025}} {{Speciesbox | image = Chelifer cancroides 8604300.jpg | parent_authority = Geoffroy, 1762 | taxon = Chelifer cancroides | authority = (Linnaeus, 1758) }}
'''''Chelifer cancroides''''', the '''house pseudoscorpion''', is a species of pseudoscorpion. It is the most widely distributed species of pseudoscorpion in the world and occurs in a range of habitats, but it is mostly synanthropic and harmless to humans.<ref name=Jacobs-pseudoscorpions>{{cite web |last=Jacobs |first=Steve |title=Pseudoscorpions |series=Department of Entomology |publisher=Penn State College of Agricultural Sciences |url=http://ento.psu.edu/extension/factsheets/pseudoscorpions |via=ento.psu.edu |access-date=5 May 2016}}</ref>
==Description== ''Chelifer cancroides'' measure {{convert|2.5|-|4.5|mm|abbr=on}} in length. The pedipalps are very long,<ref name=Levi-1948/> measuring {{convert|7|-|9|mm|abbr=on}} when extended. The body is teardrop-shaped and has a rich mahogany color. The abdomen has 12 segments, only 10 of which are easily visible. The cephalothorax has one pair of eyes.<ref name=Jacobs-pseudoscorpions/>
This species can be distinguished from other Cheliferidae by a number of features. The carapace has large setose tubercles. In males, the carapace and tergites I-VII or I-VIII have distinct lateral keels. The cheliceral hand has 4 setae, lacking seta ''sbs''. The tarsal claws of adults have a lateroventral process, except for those on the first leg pair of adult males. Additionally, the subterminal tarsal setae are denticulate. In males, coxa IV is strongly arcuate, has a large lateral process, and has a coxal sac lacking a differentiated atrium. The male genitalia have rams horn organs and an anteriorly invaginated lateral rod forming a median depression, in which lies a sclerotic rod. The female genitalia have paired spermathecae and paired median cribriform plates.<ref name=Harvey-2014>{{cite journal |last=Harvey |first=Mark S. |year=2014 |title=A review and redescription of the cosmopolitan pseudoscorpion ''Chelifer cancroides'' (Pseudoscorpiones: Cheliferidae) |journal=Journal of Arachnology |volume=42 |issue=1 |pages=86–104 |doi=10.1636/K13-57.1 |s2cid=86777132 |issn=0161-8202 |url=http://www.bioone.org/doi/abs/10.1636/K13-57.1 |via=bioone.org |url-access=subscription |lang=en }}</ref>
== Taxonomy == ''Chelifer cancroides'' was one of the two pseudoscorpion species described by Linnaeus in the 10th edition of Systema Naturae. Both Species were assigned to the mite genus ''Acarus'', then transferred to ''Phalangium'' by Linnaeus in 1767 and to ''Scorpio'' in 1775 by Fabricius. The genus ''Chelifer'' was described anonymously in 1762 to accommodate ''C. cancroides'' and has remained valid since.<ref>{{cite book |last=Geoffroy |first=É.L. |author-link=Étienne Geoffroy Saint-Hilaire |year=1762 |title=Histoire abregée des insectes qui se trouvent aux environs de Paris; dans laquelle ces animaux sont rangés suivant un ordre méthodique |lang=fr |trans-title=Abridged history of the insects found in the vicinity of Paris; in which these animals are arranged according to a methodical order |volume=2 |location=Paris, FR |publisher=Durand }}</ref> Since the genus was described over 300 species-group names have been described and all except ''C. cancroides'' have been moved to other genera or synonymized with ''C. cancroides''.<ref name=Harvey-2014/> The genus is currently monotypic, although it contains fourteen species originally described in ''Chelifer'' that are considered nomina dubia and eleven other species considered nomina nuda.<ref>{{cite web |title=''Chelifer'' {{small|Geoffroy, 1762}} |year=2023 |website=World Pseudoscorpiones Catalog |publisher=Natural History Museum of Bern |place=Bern, CH |url=https://wac.nmbe.ch/order/pseudoscorpiones/species/168 |access-date=13 October 2023 }}</ref>
== Diet == [[File:CheliferRVM.jpg|thumb|''C. cancroides'' eating a ''Dermanyssus gallinae'' mite]] ''Chelifer cancroides'' feeds on small arthropods such as psocids, fruit flies, and mites such as ''Varroa destructor''.<ref name=Krämer-Peigneur-etal-2021>{{cite journal |last1=Krämer |first1=Jonas |last2=Peigneur |first2=Steve |last3=Tytgat |first3=Jan |last4=Jenner |first4=Ronald A. |last5=van Toor |first5=Ronald |last6=Predel |first6=Reinhard |year=2021 |title=A pseudoscorpion's promising pinch: The venom of ''Chelifer cancroides'' contains a rich source of novel compounds |journal=Toxicon |volume=201 |pages=92–104 |doi=10.1016/j.toxicon.2021.08.012|pmid=34416254 |bibcode=2021Txcn..201...92K |hdl=10141/622981 |hdl-access=free |url=https://linkinghub.elsevier.com/retrieve/pii/S0041010121002233 |lang=en }}</ref>
==Reproduction== Males maintain small mating territories, few centimeters in size. When a female enters the territory, the male initiates a mating dance and eventually deposits a spermatophore, which is then picked up by the females. Fecundity is 20–40 eggs. The development from egg stage into maturity takes 10–24 months and requires three molts;<ref name=Jacobs-pseudoscorpions/> molting may involve building a silk nest.<ref name=Levi-1948/> They usually live three or four years.<ref name=Jacobs-pseudoscorpions/>
== Distribution == ''Chelifer cancroides'' has been observed in North America, Europe, Africa, and Australia.<ref>{{cite web |title=''Chelifer cancroides'' {{small|(Linnaeus, 1758)}} |place=Copenhagen, DK |publisher=Global Biodiversity Information Facility (GBIF) |url=https://www.gbif.org/species/5167813 |access-date=2021-08-10 |via=gbif.org |lang=en }}</ref>
== Habitat == ''Chelifer cancroides'' has been found under bark of trees, in caves, in bird nests, and in bee hives, and riding on bats, flies, and hymenopterans.<ref>{{cite journal |last1=Hernández-Corral |first1=Jesús |last2=Zaragoza |first2=Juan A. |last3=Micó |first3=Estefanía |date=2018-10-08 |df=dmy-all |title=New species of Pseudoscorpiones (Arachnida) from tree hollows in a Mediterranean oak forest in Spain |journal=Zootaxa |volume=4497 |issue=2 |pages=201–225 |doi=10.11646/zootaxa.4497.2.3 |pmid=30313674 |s2cid=52977326 |issn=1175-5334 |url=https://biotaxa.org/Zootaxa/article/view/zootaxa.4497.2.3 |via=biotaxa.org |url-access=subscription }}</ref> It also occurs in human structures such as houses, stables, barns, chicken coops, and bee hives.<ref name=Harvey-2014/>
== Venom == Like some other pseudoscorpions, ''C. cancroides'' has venomous pedipalps used for subduing prey. This venom contains various peptides and is toxic to bacteria (e.g. methicillin resistant ''Staphylococcus aureus''), fungi, other arthropods (e.g. aphids and ''Varroa'' mites), and mammalian cells.<ref name=Krämer-Peigneur-etal-2021/><ref>{{cite journal |last1=Krämer |first1=Jonas |last2=Lüddecke |first2=Tim |last3=Marner |first3=Michael |last4=Maiworm |first4=Elena |last5=Eichberg |first5=Johanna |last6=Hardes |first6=Kornelia |last7=Schäberle |first7=Till F. |last8=Vilcinskas |first8=Andreas |last9=Predel |first9=Reinhard |display-authors=6 |date=2022-01-14 |df=dmy-all |title=Antimicrobial, insecticidal, and cytotoxic activity of linear venom peptides from the pseudoscorpion ''Chelifer cancroides'' |journal=Toxins |volume=14 |issue=1 |page=58 |doi=10.3390/toxins14010058 |doi-access=free |issn=2072-6651 |pmc=8778599 |pmid=35051034 |lang=en }}</ref>
== References == {{Reflist|25em|refs=
<ref name=Levi-1948>{{cite journal |last=Levi |first=Herbert W. |year=1948 |title=Notes on the life history of the pseudoscorpion ''Chelifer cancroides'' (Linn.) (Chelonethida) |journal=Transactions of the American Microscopical Society |volume=67 |issue=3 |pages=290–298 |doi=10.2307/3223197 |jstor=3223197 }}</ref> }}
==External links== * {{cite web |first=Marek |last=Ples |date=c. 2022 |title=''Chelifer cancroides'' |department=Entomology, Carcinology & Arachnology |series=Lab snapshots |website=Weird Science (weirdscience.eu) |url=https://weirdscience.eu/ento/#chelifer }}
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Category:Cheliferidae Category:Cosmopolitan arachnids Category:Arachnids described in 1758 Category:Animal taxa named by Carl Linnaeus