# Urticating Hair



## mcluskyisms (Jan 24, 2010)

Just found an awesome write up on urticating hairs and decided it should be posted on here for people to read and understand just how amazing a defense mechanism these things really are!!!
*
Urticating hairs* 

Urticating hairs are one of the primary defense mechanisms used by some New World tarantulas and lepidopteran caterpillars. This term refers to the barbed hairs that cover the dorsal and posterior surface of the tarantula's abdomen or caterpillar. Many tarantula species will frequently kick hairs off their abdomens, directing them toward potential attackers. These hairs can embed themselves in the other animal's skin or eyes, thus inducing physical irritation. "Urtica" is Latin for "nettle".

*Development*

Urticating hairs do not appear at birth but form with each consecutive molt, outwardly presenting themselves around areas of more dark hairs on the upper back part of the abdomen of juveniles, widening from molt to molt, but in elder ages – merging with the main tone of abdominal coloration. Urticating hairs do not cover the entire opisthosoma and are distinct from abdominal hairs.

*Types*

There are six different types of urticating hair known in tarantulas (M. Overton, 2002). They are all different in shape and size. 

** Type I* (0.2–0.6 mm) 
** Type II* (0.5–1.5 mm)
** Ty**pe** I**II* (0.3–1.2 mm)
** Type IV* (0.06–0.2 mm)
** Type V
* Type VI*









Each type of urticating hair is believed to target different enemies. Defined targets for some hair types are unknown. 

*Type II* is not kicked off by the tarantula. Direct contact is necessary to penetrate an attacker. Tarantulas from the genera "Avicularia", "Pachistopelma" and "Iridopelma" possess Type II hairs. (Toni Hoover, 1997)

*Type III* urticating hairs are most efficient for defence against vertebrates and invertebrates.

*Types III and IV* are the most irritant to mammalian predators.
*
Types I, II, III and IV* urticating hairs can be found in the subfamilies Avicularinae and Theraphosinae.

*Type I and III* urticating hairs are representative on "Lasiodora" and "Acanthoscurria", excluding "Grammostola" (exhibits types III and IV).

*Type III* urticating hair is typically found on the species of "Theraphosa spp.", "Nhandu spp.", "Megaphoboema spp.", "Sericopelma spp.", "Eupalaestrus spp.", "Proshapalopus spp.", "Brachypelma spp.", "Cyrtopholis spp.", "Iracema spp." and other genera of subfamily Theraphosinae (Rick West, 2002).

*Type V* urticating hair is typical of the species of genus "Ephebopus". As mentioned earlier they are located on the pedipalps. They are much shorter and lighter in contrast with other types of urticating hair. These are easily thrown by the spider into the air (Marshal and Uetz, 1990).

*Type VI* urticating hair is found in the genus "Hemirrhagus" (F. Perez-Miles, 1998,)
According to Vellard (1936) and Buecherl (1951), genera with the most urticating hairs are "Lasiodora", "Grammostola" and "Acanthoscurria".

*Defensive behavior utilizing urticating hairs*

New World tarantulas will at the moment of danger, turn toward the attacker and briskly rub their hind legs against the opisthosoma throwing the urticating hairs in the direction of the enemy. 
The latest studies suggest urticating hairs from tarantulas present not just a mechanical but a chemical influence on the skin and mucous membranes. 

The cloud of small hairs will get into the mucous membrane of small mammals and cause edema, which can be fatal. 
Reaction and the degree of irritation to a defensive urticating hair barrage can vary tremendously, based on the species in question. 
Some, such as those of the Chilean rose hair ("Grammastola rosea") and the pinktoe tarantula ("Avicularia avicularia"), are fairly mild and innocuous to humans. 

Others, such as those of the Brazilian giant white knee tarantula ("Acanthoscurria geniculata"), are moderately irritating. 
Still others, such as the Goliath Birdeater ("Theraphosa blondi"), are far more severe. These hairs can result in painful rashes, and have been likened to sharp shards of fiberglass.
After a defensive maneuver, an urticating hair lobbing tarantula will have a bald spot on its abdominal region.

*Families of Lepidoptera with urticating hairs*

There are species with urticating hairs in at least eleven Lepidopteran families: the Arctiidae (tiger moths), Anthelidae (lappet moths), Bombycidae, Eupterotidae (bag shelter moths), Lasiocampidae, Limacodidae, Lymantriidae (tussock moths), Megalopygidae, Noctuidae, Notodontidae (processionary caterpillars), Nymphalidae, and Saturniidae (Matheson 1950, Riley and Johannsen 1938, Roth and Eisner 1962, Wirtz 1984). Some adults may also have urticating scales.

*Human reactions to urticating hair contact*

In humans a defensive cloud of urticating hairs can cause allergic skin reactions which can manifest itself as inflammation, rash and itching. The reactions can last for several hours or days. A chemical influence upon the skin and mucous membranes explains the different reactions of people to urticating hairs (Rick West, 2002). 
It seems likely the hairs cause an accumulative reaction in people. 
A solution of 2–2.5% hydrocortisone cream applied to the affected area may help relieve the symptoms.
A more serious consequence is urticating hair in the eyes. In this case it is necessary to immediately wash the eye thoroughly with copious amounts of cold water and see an ophthalmologist.

*Urticating hair as territorial markings*

Urticating hair is not just thrown at an enemy as a first line defence. It is also used as an indication of territory. It can be found on and around the burrow entrance and in webbing for protection (for example, some of Theraphosinae subfamily species include these hairs in cocoon silk).
Urticating hair can also be found protecting tarantula egg sacs ("Avicularia" spp. and "Theraphosa blondi" respectively). This is thought to discourage fly larvae from consuming their eggs and young.


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## mcluskyisms (Jan 24, 2010)

I forgot to put on the references!!!

_
Matheson R. 1950. Medical Entomology. (2nd ed.). Comstock Publications, Ithaca, New York. 612 p. _

_Riley WA, Johannsen OA. 1938. Medical Entomology; a Survey of Insects and Allied Forms Which Affect the Health of Man and Animals. McGraw-Hill, New York. 483 p. _

_Roth LM, Eisner T. 1962. Chemical defenses of arthropods. Annual Review of Entomology 7: 107-136. _

_Wirtz RA. 1984. Allergic and toxic reactions to non-stinging arthropods. Annual Review of Entomology 29: 47-69. _


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## 5thPhantom (Feb 8, 2010)

Fascinating! :2thumb:

It would also explain why Grammy and Lassie hairs don't bother me in the slightest, while Brachy hairs give a more severe reaction - apparently different types of hair! :whistling2: 

:no1:


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## mcluskyisms (Jan 24, 2010)

I found it fascinating too, I was in two minds whether or not just to link it up or copy it but the original piece didn't have any diagrams of the different kinds of hair so I googled about for some and I thought I may as well copy it and add the diagram to it.

The original authors did an amazing job on the write up regardless!!!

: victory:


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## Tavor21 (May 24, 2010)

Brachy hairs have no effect on me its weird i got haired in the face and neck didnt feel a thing. But when my lasidora hairs my skin goes red and spotty


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## SkinheadOi85 (Sep 28, 2008)

Very interesting read...Is this stickied?


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## Dayle (Jan 18, 2010)

very interesting read kudos to you mate


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## 5thPhantom (Feb 8, 2010)

SkinheadOi85 said:


> Very interesting read...Is this stickied?


It definitely should be!! 

*smiles sweetly at GRB* ... :whistling2: :2thumb:


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## Christie&Spence (Feb 27, 2010)

Some useful info here . Defo should be a sticky


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## GRB (Jan 24, 2008)

Will sticky - have I missed who wrote the original article however?


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## SkinheadOi85 (Sep 28, 2008)

mcluskyisms said:


> I forgot to put on the references!!!
> 
> _
> Matheson R. 1950. Medical Entomology. (2nd ed.). Comstock Publications, Ithaca, New York. 612 p. _
> ...



^ Think this is what you need Grant.


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## garlicpickle (Jan 16, 2009)

SkinheadOi85 said:


> ^ Think this is what you need Grant.


that's not who wrote the original article, it's the sources the original author used for the info he/she used to write the article.


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## mcluskyisms (Jan 24, 2010)

It doesnt really have one Author as such as its a part of the academic dictionaries & encyclopedia's of Wikipedia, I just wanted to post the article as I found it very informative and useful to people within this hobby, by no means am I taking any credit for it at all, all I did was find a diagram of the different urticating hairs edit it slightly and stitch it onto the original works, and post it here as a informative useful thread....


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## garlicpickle (Jan 16, 2009)

oh yeah, I wasn't implying you had plagiarised it :lol2: it's just I've seen this before but I can't remember where. It might have been on the T-store forum as well as on Wiki etc. Somebody must have originally gathered up the facts from the various references and cobbled them into that article, I wonder who it was as his name seems to be lost in the mists of time!


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## mcluskyisms (Jan 24, 2010)

garlicpickle said:


> oh yeah, I wasn't implying you had plagiarised it :lol2: it's just I've seen this before but I can't remember where. It might have been on the T-store forum as well as on Wiki etc. Somebody must have originally gathered up the facts from the various references and cobbled them into that article, I wonder who it was as his name seems to be lost in the mists of time!


I wish I knew too as he/she did an excellent job in explaining such an interesting characteristic of some of our favourite pets enjoyably!!!

:2thumb:


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## GRB (Jan 24, 2008)

No worries, has now been added to the FAQ section near the top (this just saves having all those stickies like before- don't worry, the thread won't disappear )


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## mcluskyisms (Jan 24, 2010)

GRB said:


> No worries, has now been added to the FAQ section near the top (this just saves having all those stickies like before- don't worry, the thread won't disappear )


Coolbeans 

: victory:


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## Oderus (Nov 24, 2009)

Good work but it might be worth adding that type II have been seen kicked off by _Avicularia versicolour _in this work (I don't have it here but il bet someone else does).

"Bertani, R., Boston, T., Evenou, Y., & Guadanucci, J. P. L. 2003. Release of urticating hairs by _Avicularia versicolor_ (Walckenaer, 1837) (Araneae, Theraphosidae). _Bulletin of the British Arachnological Society_ 12 (9): 395-398."

BTW: IIRC Some of the caterpillars that use hairs as a defence are bad ass and make spider urticating setae look like a joke :devil:


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## mcluskyisms (Jan 24, 2010)

*Ephebopus cyanognathus - Urticating Hair Defence*

I saw this video over on Arachnoboards the other day and thought it was really cool. With permission of the owner I thought it would be a great update to this thread to show how species in the genus _Ephebopus_ defend themselves via flicking their urticating hair from their pedipalps. The owner of the video was fully aware that by using his finger he could've been tagged, and that others should _never_ try to copy such actions. Although that being said, it's still a very informative video of a very unique tarantula defence system. 






I'd like to thank Jason Newland (Protectyaaaneck) for the use of his video.

: victory:


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## Stelios (Aug 28, 2009)

LOL. I didn't realise that my speakers were still on from this morning when I was listening to some tunes.
I just clicked that video and got 700 watts in face which you could say me me jump a little.:lol2:


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## mcluskyisms (Jan 24, 2010)

Stelios said:


> LOL. I didn't realise that my speakers were still on from this morning when I was listening to some tunes.
> I just clicked that video and got 700 watts in face which you could say me me jump a little.:lol2:


Hahaha win. :2thumb:


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## geckodelta (Dec 11, 2008)

mcluskyisms said:


> Hahaha win. :2thumb:


:lol2:


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## spicewwfc (Aug 26, 2009)

You're having a right sticky fest this week chris. Are you on a mission?
Great thread mate. Really interesting read.


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## pacman_addict (Jan 25, 2011)

just cleaned out my rather large salmon pink.... hairs are a nightmare. Especially when shes huge and not afraid to let em fly :devil:


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## mcluskyisms (Jan 24, 2010)

spicewwfc said:


> You're having a right sticky fest this week chris. Are you on a mission?
> Great thread mate. Really interesting read.


Haha, Nah man, this was stickied ages ago, I just wanted to add that _Ephebopus_ _cyanognathus_ video to it that I saw on AB's. Jason was kind enough to let me use it so I fired it up on here seen as though it was relevant to this thread.


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## spicewwfc (Aug 26, 2009)

mcluskyisms said:


> Haha, Nah man, this was stickied ages ago, I just wanted to add that _Ephebopus_ _cyanognathus_ video to it that I saw on AB's. Jason was kind enough to let me use it so I fired it up on here seen as though it was relevant to this thread.


Oh yeah i think i remember it now. My memory aint great, I have to watch a film 3 times before i can remember what happened in it. Lol. I saw the link in the stickies an thought you had just done it.


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## Nick Masson (Nov 8, 2010)

That was awesome! Cheers


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