Editing Velvet ant

{{Short description|Family of wasps}}
{{Automatic taxobox
| image = Velvet ants - female - various Dasymutilla.jpg
| image_caption = ''[[Dasymutilla]]'' spp.
| taxon = Mutillidae
| authority = Latreille, 1802
| subdivision_ranks = Subfamilies
| subdivision = [[Mutillinae]]<br/>
[[Myrmillinae]]<br/>
[[Pseudophotopsidinae]]<br/>
[[Rhopalomutillinae]]<br/>
[[Sphaeropthalminae]]<br/>
[[Ticoplinae]]
}}
[[File:Mutillidae-Kadavoor-2016-07-26-001.jpg|thumb|Mating pair]]

'''Velvet ants''' ('''Mutillidae''') are a [[family (biology)|family]] of more than 7,000 species of [[wasp]]s whose wingless [[female]]s resemble large, hairy [[ant]]s. Their [[common name]] velvet ant refers to their resemblance to an [[ant]], and their dense pile of hair, which most often is bright scarlet or orange, but may also be black, white, silver, or gold. Their bright colors serve as [[aposematic]] signals. They are known for their extremely painful [[stinger|sting]]s, (the sting of the species ''[[Dasymutilla klugii]]'' rated a 3 on the [[Schmidt sting pain index|Schmidt pain index]] and lasts up to 30 minutes<ref name="prev1" />), and has resulted in the common name "cow killer" or "cow ant" being applied to the species ''[[Dasymutilla occidentalis]].''<ref name="arthromuseum">{{cite web |url=http://www.uark.edu/ua/arthmuse/cowkil.html |title=Red velvet ant; cow killer |work=Arthropod Museum |publisher=University of Arkansas: Division of Agriculture |access-date=September 12, 2011 |archive-url=https://web.archive.org/web/20120526173101/http://www.uark.edu/ua/arthmuse/cowkil.html |archive-date=May 26, 2012 |url-status=dead }}</ref> However, mutillids are not aggressive and sting only in defense. In addition, the actual toxicity of their venom is much lower than that of honey bees or [[harvester ant]]s.<ref name="prev2" /> Unlike true [[ant]]s, they are solitary, and lack complex social systems.<ref name="j5" />

== Distribution ==
Mutillidae can be found worldwide with about 230 genera or subgenera and around 8,000 species worldwide. Over 400 species occur in the North American Southwest.<ref name="prev3"  />

North American Mutillidae have eight phenotypically distinct and geographically limited [[Müllerian mimicry]] rings (Desert, Eastern, Madrean, Texan, Red-headed ''Timulla'', Black-headed ''Timulla'', Tropical, and Western) making up one of the largest Müllerian mimicry complexes on the planet.<ref name="j14" /> These mimicry rings are the result of repeated convergent evolution of aposematic traits between co-occurring velvet ant species, rather than shared phylogenetic history.<ref>{{Cite journal|last1=Wilson|first1=Joseph S.|last2=Williams|first2=Kevin A.|last3=Forister|first3=Matthew L.|last4=von Dohlen|first4=Carol D.|last5=Pitts|first5=James P.|date=2012-12-11|title=Repeated evolution in overlapping mimicry rings among North American velvet ants|journal=Nature Communications|language=en|volume=3|issue=1|pages=1272|doi=10.1038/ncomms2275|pmid=23232402|issn=2041-1723|doi-access=free}}</ref> Through the evolution of [[Aposematism|aposematic]] traits in velvet ant species in the same ring, local predators have learned to avoid these well-defended wasps.

==Description==
The [[exoskeleton]] of all velvet ants is unusually tough (to the point that some entomologists have reported difficulty piercing them with steel pins when attempting to mount them for display in cabinets).{{Citation needed|date=September 2016}} This characteristic allows them to successfully invade the nests of their prey and also helps them retain moisture. Mutillids exhibit extreme [[sexual dimorphism]]. As in some related families in the [[Vespoidea]], males have wings, but females are wingless.  The males and females are so distinct in their [[Morphology (biology)|morphology]] that entomologists often find it very hard to determine whether a given male and female belong to the same species, unless they are captured while mating.<ref name="prev4" /> In some species, the male carries the smaller female aloft while mating, which is also seen in the related family [[Thynnidae]].
[[File:Dasymutilla occidentalis (3726943361).jpg|thumb|200x200px|A female [[Dasymutilla occidentalis|eastern velvet ant]]]]
As is the case for all [[Aculeata|aculeates]], only female mutillids are capable of inflicting a sting. The stinger is a modified female organ called an [[ovipositor]], which is unusually long and maneuverable in mutillids. In both sexes, a structure called a [[Stridulation|stridulitrum]] on the [[metasoma]] is used to produce a squeaking or chirping sound when alarmed. Both sexes of mutillids also bear hair-lined grooves on the side of the [[metasoma]] called felt lines. Only two other vespoid families ([[Bradynobaenidae]] and [[Chyphotidae]]) have felt lines, but the females of these families have a distinct [[pronotum]], with a transverse suture separating it from the [[mesonotum]]; in female mutillids, these two thoracic segments are completely fused. Members of the family [[Myrmosidae]], formerly classified as a subfamily of mutillids, also have a distinct pronotum in females, but lack felt lines in both sexes.

==Behavior==
Adult mutillids feed on [[nectar]]. Although some species are strictly nocturnal, females are often active during the day. Females of ''[[Tricholabiodes thisbe]]'' are sometimes active up to two hours before sunset. Guido Nonveiller (1963) hypothesized the Mutillidae are generally [[stenothermic]] and [[thermophilic]]; they may not avoid light, but rather are active during temperatures that usually occur only after sunset.

==Defense mechanisms==
Predation is one of the strongest forces natural selection uses to drive the evolution of an organism's morphology, physiology, and behavior.<ref name="j6" /><ref name="j7" /><ref name="j10" />  During this coevolution, the prey either being consumed by the predator or escaping has resulted in a plethora of impressive defensive strategies in prey species to improve the likelihood of escape. Velvet ants avoid predation using the following defense mechanisms: a venomous sting (if female), [[aposematic coloration]], a [[stridulatory organ]] in their abdomen, an alarm secretion from their mandibular gland, and a durable exoskeleton. This array of defenses has contributed to the velvet ants being attributed the title of "the indestructible insect." This title was bestowed on them after experimental interactions between velvet ants and their potential predators that resulted in the survival of the ant and the ultimate avoidance by the predator.<ref name=j4/>

The venom that velvet ants inject through their stinger has been investigated for five species of ''[[Dasymutilla]]'', revealing that they are composed primarily of peptides.<ref>{{cite journal |vauthors=Jensen T, Walker AA, Nguyen SH, Jin AH, Deuis JR, Vetter I, King GF, Schmidt JO, Robinson SD |title=Venom chemistry underlying the painful stings of velvet ants (Hymenoptera: Mutillidae) |journal=Cell Mol Life Sci |volume=78 |issue=12 |pages=5163–77 |date=June 2021 |pmid=33970306 |pmc=11072429 |doi=10.1007/s00018-021-03847-1 }}</ref> According to one researcher, the painfulness of the sting of ''Dasymutilla klugii'' outscored 58 other species of stinging insects tested; the only species this researcher rated as having a more painful sting were ''[[Paraponera clavata]]'' (bullet ant), ''[[Synoeca septentrionalis]]'' (warrior wasp), and ''[[Pepsis]]'' and ''[[Hemipepsis]]'' spp. ([[tarantula hawk]]s).<ref name="j12" /> In an experimental setting, only two lizard species (one [[Teiidae|whiptail]] and one [[side-blotched lizard]]) attacked a velvet ant it was exposed to.<ref name=j4 /> In both cases the velvet ants were exhibiting rapid lateral and vertical movements to ward off an attack. Once the attack occurred the velvet ants would immediately sting the lizards. This sting resulted in the dropping of the ants in both cases and avoidance for the remainder of the trial.<ref name="j4" /> The side-blotched lizard was found dead in its tank 24 hours later.<ref name=j4 /> The side-blotched lizard is a natural predator of velvet ants, while the whiptail is not.<ref name=j4 />
The aposematic coloration of velvet ants often corresponds to a specific [[Müllerian mimicry]] ring consisting of dozens of species. This offers protection because many local predators have learned to avoid prey with this same coloration.<ref name="j14" /> To test the aposematic coloration on birds, mealworms were painted to resemble a velvet ant. During these trials, none of the painted mealworms were consumed, while all the control mealworms were consumed immediately.<ref name=j4 /> However, the painted mealworms were attacked by the birds, but the birds immediately ceased the attack.<ref name=j4 /> These experiments provide evidence that the aposematic coloration of velvet ants causes their predators to hesitate, acting as a visual defense mechanism.

The stridulatory organ that velvet ants possess produces an audible squeaking when the abdomen is contracted.<ref name="j11" /> This mechanism is an auditory cue warning predators that are about to attack to stay away. In one experiment, every time a [[shrew]] got within 1 meter of a velvet ant, the velvet ant would begin stridulating.<ref name="j4" /> Stridulations became more frequent as the predator moved closer to the velvet ant, and the shrew never attempted to attack the velvet ant. However, different scenarios with shrews have shown that the velvet ant would also stridulate after the shrew attacked it. Every time this occurred the shrew dropped the wasp.<ref name="j4" />

The exoskeleton of the velvet ant is remarkably strong. It required 11 times more force to crush than that of the honeybee.<ref name="j11" /> As well as being durable, the exoskeleton is also round, making it more difficult for predators to pierce it with attempted stings or bites. During all the trials that led to the fracture of a velvet ant's exoskeleton, a total of 4 times resulted in the death of that velvet ant within 24 hours. Aside from protection from predators, the exoskeleton also helps control moisture.<ref name="j11" />

Due to these strong defense mechanisms, local predators generally avoid the velvet ants, so it has been difficult to determine their predators.<ref name=j4 /> One study found tropical and subtropical iguanian lizards ([[Dactyloidae]]) to be a local predator of velvet ants in the black-headed ''[[Timulla]]'' and tropical mimicry rings.<ref>{{Cite journal|last1=Pan|first1=Aaron D.|last2=Williams|first2=Kevin A.|last3=Wilson|first3=Joseph S.|date=2017-02-01|title=Are diurnal iguanian lizards the evolutionary drivers of New World female velvet ant (Hymenoptera: Mutillidae) Müllerian mimicry rings?|journal=Biological Journal of the Linnean Society|volume=120|issue=2|pages=436–447|doi=10.1111/bij.12894|issn=0024-4066|doi-access=free}}</ref>

== Life cycle ==
[[File:Nemka viduata viduata - 2012-10-17.webm|left|thumb|thumbtime=1:47|A female of ''Nemka viduata viduata'' (Pallas, 1773) looks for a nest of ''Bembix oculata'' to deposit her eggs.]]
Male mutillids fly in search of females; after mating, the female enters a host insect nest, typically a ground-nesting bee or wasp burrow, and deposits one egg near each [[larva]] or [[pupa]]. Only a few species are known to parasitize other types of hosts;<ref>{{cite journal |first=Denis J. |last=Brothers |title=Phylogeny and classification of the aculeate Hymenoptera, with special reference to Mutillidae |journal=University of Kansas Science Bulletin |volume=50 |issue=11 |pages=483–648 |date=1975 |url=https://digitalcommons.usu.edu/bee_lab_bo/210/ }}</ref> exceptions include the European velvet ant, ''[[Mutilla europaea]]'', one of the only species that attacks social bees (e.g., ''[[Bombus]]''), and the genus ''[[Pappognatha]]'', whose hosts are tree-dwelling [[orchid bee]]s. The mutillid larvae then develop as [[Parasitoid|idiobiont ectoparasitoids]], eventually killing their immobile larval/pupal hosts within a week or two. Velvet ants exhibit [[haplodiploid]] sex determination, as do other members of the superfamily [[Vespoidea]].
{{clear}}

==Taxonomy==
Recent classifications of [[Vespoidea]] ''sensu lato'' (beginning in 2008) concluded that the family '''Mutillidae''' contained one subfamily that was unrelated to the remainder, and this subfamily was removed to form a separate family [[Myrmosidae]].<ref name="Pilgrim2008">{{cite journal|last1=Pilgrim |first1=E. |last2=von Dohlen |first2=C. |last3=Pitts |first3=J. |year=2008 |title= Molecular phylogenetics of Vespoidea indicate paraphyly of the superfamily and novel relationships of its component families and subfamilies |journal= Zoologica Scripta |volume= 37 |issue= 5 |pages=539–560 |doi=10.1111/j.1463-6409.2008.00340.x|s2cid=85905070 }}</ref><ref name="Johnson2013">{{cite journal|last1=Johnson |first1=B.R. |year=2013 |title= Phylogenomics Resolves Evolutionary Relationships among Ants, Bees, and Wasps |journal= Current Biology |volume=23 |issue=20 |pages=2058–62 |doi=10.1016/j.cub.2013.08.050|display-authors=etal |pmid=24094856|doi-access=free }}</ref>

[[File:Brothers 2017 Proposed higher classification of Mutillidae.jpg|thumb|centre|800px|Proposed higher classification of Mutillidae<ref name="Brothers & Lelej 2017">{{cite journal |last1=Brothers |first1=DJ |last2=Lelej |first2=AS |title=Phylogeny and higher classification of Mutillidae (Hymenoptera) based on morphological reanalyses |journal=Journal of Hymenoptera Research |date=2017 |volume=60 |pages=1–97 |doi=10.3897/jhr.60.20091|doi-access=free }}</ref>]]

==See also==
* [[List of Mutillidae genera]]

==References==
{{Reflist|refs=
<ref name="prev1">{{cite book |first1=David L. |last1=Evans |first2=Justin O. |last2=Schmidt |chapter=Hymenopteran venoms: striving toward the ultimate defense against vertebrates |title=Insect Defenses: Adaptive Mechanisms and Strategies of Prey and Predators |chapter-url=https://books.google.com/books?id=jpxkhS7O0p0C&pg=PP1 |year=1990 |publisher=SUNY Press |isbn=978-0-88706-896-6 |pages=387–419}}</ref>
<ref name="prev2">{{cite book |last=Meyer |first=W.L. |title=Book of Insect Records |date=1996 |publisher=University of Florida |chapter-url=http://entnemdept.ifas.ufl.edu/walker/ufbir/chapters/chapter_23.shtml#schmidt_blum_overal_1980 |chapter=Most Toxic Insect Venom}}</ref>
<ref name="prev3">{{cite web|url=http://entomology.ifas.ufl.edu/creatures/misc/wasps/mutillidae.htm|title=Mutillidae — velvet ants|publisher=University of Florida/IFAS|website=Featured Creatures}}</ref>
<ref name="prev4">{{Cite book|title=Hymenoptera of the world : an identification guide to families|date=1993 |last1=Goulet |first1=Henri |last2=Huber |first2=John T. |publisher=Agriculture Canada |isbn=978-0-660-14933-2 |oclc=28024976}}</ref>
<ref name="j4">{{cite journal |last1=Gall |first1=B.G. |last2=Spivey |first2=K.L |last3=Chapman |first3=T.L. |last4=Delph |first4=R.J. |last5=Brodie |first5=E.D. Jr. |last6=Wilson |first6=J.S. |title=The indestructible insect: Velvet ants from across the United States avoid predation by representatives from all major tetrapod clades. |journal=Ecology and Evolution |date=2018 |volume=8 |issue=11 |pages=5852–62 |doi=10.1002/ece3.4123|pmid=29938098 |pmc=6010712 }}</ref>
<ref name="j5">{{cite journal |first=J.H. |last=Hunt |title=Trait mapping and salience in the evolution of eusocial vespid wasps |journal=Evolution |volume=53 |issue=1 |pages=225–237 |year=1999 |doi=10.1111/j.1558-5646.1999.tb05348.x |pmid=28565172 |s2cid=205781311 |url=http://www4.ncsu.edu/~jhhunt/TraitMapping&Salience.pdf }}</ref>
<ref name="j6">{{cite journal |last1=Lima |first1=S.L. |last2=Dill |first2=L.M. |title=Behavioral decisions made under the risk of predation: A review and prospect |journal=Canadian Journal of Zoology |date=1990 |volume=68 |issue=4 |pages=619–640|doi=10.1139/z90-092 }}</ref>
<ref name="j7">{{cite book |first=A.S. |last=Lelej |title=Catalogue of the Mutillidae (Hymenoptera) of the Palaearctic region |publisher=Dalnauka |location=Vladivostok |year=2002 |isbn= 978-5-8044-0280-9 |url=http://antvid.org/PDF/2002_Cat_Pal_1-172.pdf }}</ref>
<ref name="j10">{{cite book |first1=G. |last1=Nonveiller |first2=F.J. |last2=Suarez |title=Catalogue of the Mutillidae, Myrmosidae and Bradynobaenidae of the Neotropical Region including Mexico (Insecta: Hymenoptera |publisher=SPB Academic |year=1990 |isbn=978-90-5103-048-8 |volume=18 |series=Hymenopterorum catalogus |oclc=889162931}}</ref>
<ref name="j11">{{cite journal |last1=Schmidt |first1=J.O. |last2=Blum |first2=M.S. |title=Adaptations and responses of ''Dasymutilla occidentalis'' (Hymenoptera: Mutillidae) to predators |journal=Entomologia Experimentalis et Applicata |date=1977 |volume=21 |issue=2 |pages=99–111|doi=10.1111/j.1570-7458.1977.tb02663.x |s2cid=83847876 }}</ref>
<ref name="j12">{{cite journal |last1=Starr |first1=C.K. |title=A simple pain scale for field comparison of hymenopteran stings |journal=Journal of Entomological Science |date=1985 |volume=20 |issue=2 |pages=225–232|doi=10.18474/0749-8004-20.2.225 }}</ref>

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<ref name="j13">{{cite journal |last1=Vitt |first1=L.J. |last2=Cooper |first2=W.E. |title=Feeding responses of skinks (''Eumeces laticeps'') to velvet ants (''Dasymutilla occidentalis''). |journal=Journal of Herpetology |date=1988 |volume=22 |issue=4 |pages=485–8|doi=10.2307/1564347 |jstor=1564347 }}</ref>
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<ref name="j14">{{cite journal |last1=Wilson |first1=J.S. |last2=Jahner |first2=J.P. |last3=Forister |first3=M.L. |last4=Sheehan |first4=E.S. |last5=Williams |first5=K.A. |last6=Pitts |first6=J.P. |title=North American velvet ants form one of the world's largest known Mullerian mimicry complexes |journal=Current Biology |date=2015 |volume=25 |issue=16|pages=R704-6 |doi=10.1016/j.cub.2015.06.053 |pmid=26294178 |doi-access=free }}</ref>
}}

===Sources===
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* <!--<ref name="j3">-->{{cite book |last1=Endler |first1=J.A. |title=Natural selection in the wild |publisher=[[Princeton University Press]] |orig-date=1986 |isbn=978-0-691-20951-7 |doi=10.12987/9780691209517 |series=Monographs in Population Biology |volume=101 |date=2020 }}
* <!--<ref name="j8">-->{{cite journal |last1=Mickel |first1=C.E. |title=Biological and taxonomic investigations on the mutillid wasps. |journal=United States National Museum Bulletin |date=1928 |volume=143 |issue=143 |pages=1–351 |doi=10.5479/si.03629236.143.1|url=https://www.biodiversitylibrary.org/part/70820 }}
* <!--<ref name="j9">-->{{cite book |first=Lorus J. |last=Milne |title=National Audubon Society Field Guide to North American Insects and Spiders |series=Audubon Society Field Guide (Turtleback) |year=1980 |publisher=Knopf |isbn=978-0-394-50763-7 |url-access=registration |url=https://archive.org/details/nationalaudubons00miln }}
{{Refend}}

==External links==
* {{Commons category-inline|Mutillidae}}
* [http://lancaster.unl.edu/pest/resources/CowKiller.shtml Cow Killer] at the [[University of Nebraska-Lincoln]] Extension in [[Lancaster County, Nebraska]]
*[http://entnemdept.ufl.edu/creatures/misc/wasps/mutillidae.htm Mutillidae] at the [[University of Florida]] [[Institute of Food and Agricultural Sciences]]
* [https://texasinsects.tamu.edu/red-velvet-ant-or-cow-killer/ Red Velvet Ant or "Cow Killer"], Texas A&M Field Guide to Common Texas Insects

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[[Category:Mutillidae| ]]
[[Category:Apocrita families]]
[[Category:Aposematic animals]]
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