Recluse spider - wikipedia Recluse spider Recluse spider Loxosceles gaucho, Brazil Scientific classification Kingdom : Animalia Phylum : Arthropoda Class : Arachnida Order : Araneae Family : Sicariidae Genus : Loxosceles Heineken & Lowe, 1832 Species see article Diversity 100 species The recluse spiders or brown spiders, genus Loxosceles ( / ˌlɒkˈsɒsɪliz / ), also known as fiddle - backs, violin spiders, or reapers, are a genus of venomous spiders known for their bite, which sometimes produces a characteristic set of symptoms known as loxoscelism. Recluse spiders are now identified as members of the family Sicariidae, having formerly been placed in their own family, the Loxoscelidae. Although recluse spiders have a bad reputation, they are usually not aggressive. Contents 1 Relation with other spiders 2 Habitat and appearance 3 Venom components and effects 4 Species 5 See also 6 Footnotes 7 External links Relation with other spiders Sicariidae are of the superfamily Scytodoidea. Other families in the Scytodoidea include Drymusidae, Scytodidae, and Periegopidae. Habitat and appearance Loxosceles is distributed nearly worldwide in warmer areas. All have six eyes arranged in three groups of two ( dyads ) and some are brownish with a darker brown characteristic violin marking on the cephalothorax. However, the `` violin marking '' can not be used as a reliable way to identify the spider as thousands of species of spider have similar markings. Spiders come with many markings varying greatly within the same species. Most Loxosceles can live for one and a half to two years. Many species of this genus can live for very long times without food or water. They are about 7 -- 12 mm long. The most common and most famous species in the United States is the brown recluse spider ( Loxosceles reclusa ). It is found in a large area of the Midwest, west to Colorado and the New Mexico state line and east to northern Georgia. Sporadic records from other locations only represent incidental introductions, not established populations. The brown recluse feeds on whatever small prey is available, and has been observed to prefer scavenging over actively hunting. Other notable members of this genus include the Chilean recluse spider ( L. laeta ) and the Mediterranean recluse spider ( L. rufescens ). Recently, concerns have been raised regarding recluses spreading faster due to warmer air carrying them farther as a result of changing climate. On the contrary, newly hatched recluses do not travel via ballooning and thus the populations are confined to very tight spaces with dense populations. Venom components and effects Loxosceles spiders, like Sicarius species, have potent tissue - destroying venoms containing the dermonecrotic agent, sphingomyelinase D, which is otherwise found only in a few pathogenic bacteria. Recent research has indicated the venom is composed largely of sulfated nucleosides, though these compounds are relatively new discoveries, so little is known about them. The venom produces necrotic lesions that are slow to heal and may require skin grafts. Rarely, the venom is carried by the bloodstream, causing red blood cell destruction. The venom is identical in male and female spiders, but females can have almost twice the concentration of toxins. For unknown reasons, the toxicity of the venom to mammalian species varies ; recluse bites may cause necrosis in humans, rabbits, and guinea pigs, but not in mice or rats. The Chilean recluse ( L. laeta ) supposedly has a more potent venom, which results in systemic involvement more often. This spider was introduced to the Los Angeles area ( Alhambra, Sierra Madre, and Monterey Park ). No verified bites and the subsequent systemic hemolysis have been documented, even though it has been known there for over 30 years. All Loxosceles species that have been tested have venoms similar to that of the brown recluse and all should be avoided. In general, though, they are not aggressive and commonly occupy human dwellings without causing problems. Many types of skin wounds are mistaken for or assumed to be the result of a recluse spider bite. Several diseases can mimic the lesions of the bite, including Lyme disease, various fungal and bacterial infections, and the first sore of syphilis. It is important to associate the spider directly with the bite to avoid improper treatment, and to successfully treat common infections or other conditions if no spider was seen. Bites most often occur as a defense when the spider is trapped against the skin, in clothing, for example. Insecticides often fail to kill the spider, instead intoxicating its nervous system and inducing erratic behavior. The bite of a recluse spider can generally be categorized into one of the following groups : Unremarkable - self - healing minute damage Mild reaction - self - healing damage with itchiness, redness, patterns of aggressive behavior and a mild lesion. Dermonecrotic - the uncommon, `` classic '' recluse bite, producing a necrotic skin lesion. About 66 % of necrotic bite lesions heal with no complications. In extreme cases, the lesion may be up to 40 centimeters wide, last for several months, and heal with a permanent scar. Systemic or viscerocutaneous - an extremely rare, systemic reaction to envenomation of the bloodstream. This reaction is more common in obese victims, because the venom destroys adipose tissue. It is more often systemic in children, though there has never been a verifiable death as a result of a brown recluse spider bite in North America. Most bites are unremarkable or mild. Species There are about 100 species of Loxosceles. Species include : Loxosceles accepta Chamberlin, 1920 -- Peru Loxosceles adelaida Gertsch, 1967 -- Brazil Loxosceles alamosa Gertsch & Ennik, 1983 -- Mexico Loxosceles alicea Gertsch, 1967 -- Peru Loxosceles amazonica Gertsch, 1967 -- Brazil Loxosceles anomala ( Mello - Leitão, 1917 ) -- Brazil Loxosceles apachea Gertsch & Ennik, 1983 -- United States, Mexico Loxosceles aphrasta Wang, 1994 -- China Loxosceles aranea Gertsch, 1973 -- Mexico Loxosceles arizonica Gertsch & Mulaik, 1940 -- USA Loxosceles aurea Gertsch, 1973 -- Mexico Loxosceles baja Gertsch & Ennik, 1983 -- Mexico Loxosceles barbara Gertsch & Ennik, 1983 -- Mexico Loxosceles belli Gertsch, 1973 -- Mexico Loxosceles bettyae Gertsch, 1967 -- Peru Loxosceles blancasi Gertsch, 1967 -- Peru Loxosceles blanda Gertsch & Ennik, 1983 -- USA Loxosceles boneti Gertsch, 1958 -- Mexico, El Salvador Loxosceles candela Gertsch & Ennik, 1983 -- Mexico Loxosceles caribbaea Gertsch, 1958 -- Greater Antilles Loxosceles carmena Gertsch & Ennik, 1983 -- Mexico Loxosceles chinateca Gertsch & Ennik, 1983 -- Mexico Loxosceles colima Gertsch, 1958 -- Mexico Loxosceles conococha Gertsch, 1967 -- Peru Loxosceles coquimbo Gertsch, 1967 -- Chile Loxosceles coyote Gertsch & Ennik, 1983 -- Mexico Loxosceles cubana Gertsch, 1958 -- Cuba, Bahama Islands Loxosceles deserta Gertsch, 1973 -- USA, Mexico Loxosceles devia Gertsch & Mulaik, 1940 -- USA, Mexico Loxosceles fontainei Millot, 1941 -- Guinea Loxosceles foutadjalloni Millot, 1941 -- Guinea Loxosceles francisca Gertsch & Ennik, 1983 -- Mexico Loxosceles frizzelli Gertsch, 1967 -- Peru Loxosceles gaucho Gertsch, 1967 -- Brazil, Tunisia Loxosceles gloria Gertsch, 1967 -- Ecuador, Peru Loxosceles guatemala Gertsch, 1973 -- Guatemala Loxosceles harrietae Gertsch, 1967 -- Peru Loxosceles herreri Gertsch, 1967 -- Peru Loxosceles hirsuta Mello - Leitão, 1931 -- Brazil, Paraguay, Argentina Loxosceles huasteca Gertsch & Ennik, 1983 -- Mexico Loxosceles immodesta ( Mello - Leitão, 1917 ) -- Brazil Loxosceles inca Gertsch, 1967 -- Peru Loxosceles insula Gertsch & Ennik, 1983 -- Mexico Loxosceles intermedia Mello - Leitão, 1934 -- Brazil, Argentina Loxosceles jaca Gertsch & Ennik, 1983 -- Mexico Loxosceles jamaica Gertsch & Ennik, 1983 -- Jamaica Loxosceles jarmila Gertsch & Ennik, 1983 -- Jamaica Loxosceles julia Gertsch, 1967 -- Peru Loxosceles kaiba Gertsch & Ennik, 1983 -- USA Loxosceles lacroixi Millot, 1941 -- Ivory Coast Loxosceles lacta Wang, 1994 -- China Loxosceles laeta ( Nicolet, 1849 ) -- South America, introduced to North America, Finland and Australia Loxosceles lawrencei Caporiacco, 1955 -- Venezuela, Trinidad, Curaçao Loxosceles lutea Keyserling, 1877 -- Colombia, Ecuador Loxosceles luteola Gertsch, 1973 -- Mexico Loxosceles manuela Gertsch & Ennik, 1983 -- Mexico Loxosceles martha Gertsch & Ennik, 1983 -- USA Loxosceles meruensis Tullgren, 1910 -- Tanzania Loxosceles misteca Gertsch, 1958 -- Mexico Loxosceles mulege Gertsch & Ennik, 1983 -- Mexico Loxosceles nahuana Gertsch, 1958 -- Mexico Loxosceles neuvillei Simon, 1909 -- Somalia, East Africa Loxosceles olmea Gertsch, 1967 -- Peru Loxosceles pallidecolorata ( Strand, 1906 ) -- Ethiopia Loxosceles palma Gertsch & Ennik, 1983 -- USA, Mexico Loxosceles panama Gertsch, 1958 -- Panama Loxosceles parrami Newlands, 1981 -- South Africa Loxosceles piura Gertsch, 1967 -- Peru Loxosceles pucara Gertsch, 1967 -- Peru Loxosceles puortoi Martins, Knysak & Bertani, 2002 -- Brazil Loxosceles reclusa Gertsch & Mulaik, 1940 -- North America Loxosceles rica Gertsch & Ennik, 1983 -- Costa Rica Loxosceles rosana Gertsch, 1967 -- Peru Loxosceles rothi Gertsch & Ennik, 1983 -- Mexico Loxosceles rufescens ( Dufour, 1820 ) -- Cosmopolitan Loxosceles rufipes ( Lucas, 1834 ) -- Guatemala, Panama, Colombia Loxosceles russelli Gertsch & Ennik, 1983 -- USA Loxosceles sabina Gertsch & Ennik, 1983 -- USA Loxosceles seri Gertsch & Ennik, 1983 -- Mexico Loxosceles similis Moenkhaus, 1898 -- Brazil Loxosceles smithi Simon, 1897 -- Ethiopia Loxosceles sonora Gertsch & Ennik, 1983 -- Mexico Loxosceles spadicea Simon, 1907 -- Peru, Bolivia, Argentina Loxosceles speluncarum Simon, 1893 -- South Africa Loxosceles spinulosa Purcell, 1904 -- Southern Africa Loxosceles surca Gertsch, 1967 -- Peru Loxosceles taeniopalpis Simon, 1907 -- Ecuador Loxosceles taino Gertsch & Ennik, 1983 -- Bahama Islands, Jamaica, Hispaniola Loxosceles tehuana Gertsch, 1958 -- Mexico Loxosceles tenango Gertsch, 1973 -- Mexico Loxosceles teresa Gertsch & Ennik, 1983 -- Mexico Loxosceles tlacolula Gertsch & Ennik, 1983 -- Mexico Loxosceles unicolor Keyserling, 1887 -- South America Loxosceles valdosa Gertsch, 1973 -- Mexico Loxosceles valida Lawrence, 1964 -- South Africa Loxosceles variegata Simon, 1897 -- Paraguay Loxosceles virgo Gertsch & Ennik, 1983 -- Virgin Islands Loxosceles vonwredei Newlands, 1980 -- Namibia Loxosceles weyrauchi Gertsch, 1967 -- Peru Loxosceles yucatana Chamberlin & Ivie, 1938 -- Mexico, Belize, Guatemala Loxosceles zapoteca Gertsch, 1958 -- Mexico See also Wikispecies has information related to : Loxosceles List of Sicariidae species Spider families List of spiders associated with cutaneous reactions Chilean recluse Footnotes Jump up ^ Binkovitz, Leah. `` Why We Should All Celebrate Save a Spider Day ''. Smithsonian. Retrieved 2017 - 07 - 17. Jump up ^ Sandidge, J. ( 2003 ). `` Arachnology : Scavenging by brown recluse spiders ''. Nature. 426 ( 30 ) : 30. Bibcode : 2003Natur. 426... 30S. PMID 14603305. doi : 10.1038 / 426030a. ^ Jump up to : Vetter, R.S. ( 2008 ). `` Spiders of the genus Loxosceles : a review of biological, medical and psychological aspects regarding envenomations '' ( PDF ). Journal of Arachnology. 36 ( 3 ) : 150 -- 163. doi : 10.1636 / RSt08 - 06.1. Jump up ^ Binford, G.J. ; et al. ( 2005 ). `` Sphingomyelinase D from venoms of Loxosceles spiders : evolutionary insights from cDNA sequences and gene structure '' ( PDF ). Toxicon. 45 ( 5 ) : 547 -- 560. PMID 15777950. doi : 10.1016 / j. toxicon. 2004.11. 011. Jump up ^ Schroeder, F.C. ; et al. ( 2008 ). `` NMR - spectroscopic screening of spider venom reveals sulfated nucleosides as major components for the brown recluse and related species ''. PNAS. 105 ( 38 ) : 14283 -- 14287. Bibcode : 2008PNAS... 10514283S. doi : 10.1073 / pnas. 0806840105. ^ Jump up to : Swanson, D.L. ; Vetter, R.S. ( 2006 ). `` Loxoscelism '' ( PDF ). Clinics in Dermatology. 24 ( 3 ) : 213 -- 221. PMID 16714202. doi : 10.1016 / j. clindermatol. 2005.11. 006. Retrieved 12 April 2011. Jump up ^ Vetter, R. and D. Barger. ( 2002 ). `` An infestation of 2,055 brown recluse spiders ( Araneae : Sicariidae ) and no envenomations in a Kansas home : implications for bite diagnoses in nonendemic areas ''. J Med Entomol. 39 ( 6 ) : 948 -- 51. PMID 12495200. doi : 10.1603 / 0022 - 2585 - 39.6. 948. Jump up ^ Vetter, R. and S. Bush. ( 2002 ). `` The diagnosis of brown recluse spider bite is overused for dermonecrotic wounds of uncertain etiology ''. Ann Emerg Med. 39 ( 5 ) : 544 -- 6. PMID 11973562. doi : 10.1067 / mem. 2002.123594. Jump up ^ `` UCR Spiders Site ''. Retrieved 28 October 2014. Jump up ^ Hite, J.M. ( 1966 ). The biology of the brown recluse spider. Kansas State University. Jump up ^ Pauli, I. ; et al. ( 2006 ). `` The efficacy of antivenom in loxoscelism treatment ''. Toxicon. 48 ( 2 ) : 123 -- 37. doi : 10.1016 / j. toxicon. 2006.05. 005. Jump up ^ `` Dispelling the Myths About Brown Recluse Spiders and Their Bites ''. Retrieved 18 April 2016. Jump up ^ Wright, S.W. ; et al. ( 1997 ). `` Clinical presentation and outcome of brown recluse spider bite ''. Annals of Emergency Medicine. 30 : 28 -- 32. doi : 10.1016 / S0196 - 0644 ( 97 ) 70106 - 9. Jump up ^ Anderson, P.C. ( 1998 ). `` Missouri brown recluse spider : a review and update ''. Missouri Medicine. 95 ( 7 ) : 318 -- 22. PMID 9666677. Jump up ^ Cacy, J. and J.W. Mold. ( 1999 ). `` The clinical characteristics of brown recluse spider bites treated by family physicians : an OKPRN study ''. Journal of Family Practice. 48 ( 7 ) : 536 -- 42. PMID 10428252. External links Arachnology Home Pages : Loxosceles : Recluse spiders Biodiversity Explorer : Family Sicariidae. World Spider Catalog. 2014. Vetter, R. 2003. Causes of Necrotic Wounds other than Brown Recluse Spider Bites. Vetter, R. 2003. Myth of the Brown Recluse Fact, Fear, and Loathing. Pictures of L. reclusa and wound ( free for noncommercial use ) Retrieved from `` https://en.wikipedia.org/w/index.php?title=Recluse_spider&oldid=794740591 '' Categories : Sicariidae Venomous spiders Spiders of North America Spiders of South America Spiders of Asia Spiders of Africa Hidden categories : Articles using diversity taxobox Articles with ' species ' microformats All articles with unsourced statements Articles with unsourced statements from December 2016 Articles with unsourced statements from October 2016 Talk Contents About Wikipedia Wikispecies Беларуская Català Cebuano Deutsch Español Français Nederlands Português Română Русский Svenska Tiếng Việt Winaray Edit links This page was last edited on 9 August 2017, at 19 : 54. 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Question: how many species of recluse spiders are there
Answer: about 100