''Latrodectus'' is a broadly distributed
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...
of
spider
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...
s with several species that are commonly known as the true widows. This group is composed of those often loosely called black widow spiders, brown widow spiders, and similar spiders.
However, the diversity of species is much greater. A member of the family
Theridiidae
Theridiidae, also known as the tangle-web spiders, cobweb spiders and comb-footed spiders, is a large family of Araneomorphae, araneomorph spiders first described by Carl Jakob Sundevall in 1833. This diverse, globally distributed family includes ...
, this genus contains 34
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
,
[ which include several North American "black widows" (southern black widow '']Latrodectus mactans
''Latrodectus mactans'', known as southern black widow or simply black widow, and the shoe-button spider, is a venomous species of spider in the genus ''Latrodectus''. The females are well known for their distinctive black and red coloring and f ...
'', western black widow ''Latrodectus hesperus
''Latrodectus hesperus'', the western black widow spider or western widow, is a venomous spider species found in western regions of North America. The female's body is 14–16 mm (1/2 in) in length and is black, often with an hourglass-shape ...
'', and northern black widow ''Latrodectus variolus
''Latrodectus variolus'', the northern black widow spider or northern widow, is a venomous species of spider in the genus ''Latrodectus'' of the family Theridiidae. The population is closely related to the southern black widow, ''Latrodectus mact ...
''). Besides these, North America also has the red widow ''Latrodectus bishopi
''Latrodectus bishopi'' is the scientific name for the red widow spider, which is endemic to certain habitats of central and southern Florida, where it lives primarily in sand dunes dominated by sand pine, ''Pinus clausa'' – a type of vegetati ...
'' and the brown widow ''Latrodectus geometricus
''Latrodectus geometricus'', commonly known as the brown widow, brown button spider, grey widow, brown black widow, house button spider or geometric button spider, is one of the widow spiders in the genus ''Latrodectus''. As such, it is a 'cousi ...
'', which, in addition to North America, has a much wider geographic distribution. Elsewhere, others include the European black widow
''Latrodectus tredecimguttatus'', also known as the Mediterranean black widow, or the European black widow, is a species in the genus ''Latrodectus'' of the widow spiders. It is commonly found throughout the Mediterranean region, ranging from ...
(''Latrodectus tredecimguttatus''), the Australian redback black widow (''Latrodectus hasseltii'') and the closely related New Zealand katipō
The katipō (''Latrodectus katipo'') is an endangered species of spider native to New Zealand. It is one of many species in the genus ''Latrodectus'', such as the Australian redback (''L. hasseltii''), and the North American black widow. The ...
(''Latrodectus katipo''), several different species in Southern Africa that can be called button spider
Button spider is a common name used in Southern Africa to refer to local members of the spider genus, ''Latrodectus'', the family Theridiidae. There are both black and brown button spiders in Southern Africa, that are known elsewhere as widow sp ...
s, and the South American black-widow spiders (''Latrodectus corallinus
''Latrodectus corallinus'' is a species of widow spider native to Argentina. It is approximately in size, and is primarily black with large, red markings on its abdomen, as well as a red, square-like ring under its abdomen.
Distribution and h ...
'' and ''Latrodectus curacaviensis
''Latrodectus curacaviensis'' is a species of black widow spider, that belongs to the genus ''Latrodectus''. It is known as the South American black widow, Brazilian black widow or Araña del trigo.
Description
Like many black widow species, f ...
''). Species vary widely in size. In most cases, the females are dark-coloured and can be readily identified by reddish markings on the central underside (ventral) abdomen, which are often hourglass
An hourglass (or sandglass, sand timer, sand clock or egg timer) is a device used to measure the passage of time. It comprises two glass bulbs connected vertically by a narrow neck that allows a regulated flow of a substance (historically sand) ...
-shaped.
These small spiders have an unusually potent venom containing the neurotoxin latrotoxin
A latrotoxin is a high-molecular mass neurotoxin found in the venom of spiders of the genus ''Latrodectus'' (widow spiders) as well as at least one species of another genus in the same family, '' Steatoda nobilis''. Latrotoxins are the main activ ...
, which causes the condition latrodectism
Latrodectism () is the illness caused by the bite of ''Latrodectus'' spiders (the black widow spider and related species). Pain, muscle rigidity, vomiting, and sweating are the symptoms of latrodectism.
There are several spider species all named b ...
, both named after the genus. Female widow spiders have unusually large venom glands, and their bite can be particularly harmful to large vertebrates, including humans. However, despite their notoriety, ''Latrodectus'' bites rarely cause death or produce serious complications. Only the bites of the females are dangerous to humans.
Description
Female widow spiders are typically dark brown or a shiny black in colour when they are full grown, usually exhibiting a red or orange hourglass on the ventral
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek language, Greek roots, describe something in its standard anatomical position. Th ...
surface (underside) of the abdomen; some may have a pair of red spots or have no marking at all. The male widow spiders often exhibit various red or red and white markings on the dorsal
Dorsal (from Latin ''dorsum'' ‘back’) may refer to:
* Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism
* Dorsal, positioned on top of an aircraft's fuselage
* Dorsal co ...
surface (upper side) of the abdomen, ranging from a single stripe to bars or spots, and juveniles are often similar to the male pattern. Females of a few species are paler brown and some have no bright markings. The bodies of black widow spiders range from in size; some females can measure in their body length (not including legs). Including legs, female adult black widows generally measure .
Behaviour
The prevalence of sexual cannibalism
Sexual cannibalism is when an animal, usually the female, cannibalizes its mate prior to, during, or after copulation.Polis, G.A. & Farley, R.D. Behavior and Ecology of Mating in the journal of Arachnology 33-46 (1979). It is a trait observed in m ...
, a behaviour in which the female eats the male after mating, has inspired the common name
In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...
"widow spiders". This behaviour may promote the survival odds of the offspring
In biology, offspring are the young creation of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This ca ...
; however, females of some species only rarely show this behaviour, and much of the documented evidence for sexual cannibalism has been observed in laboratory cages where the males could not escape. Male black widow spiders tend to select their mates by determining if the female has eaten already to avoid being eaten themselves. They are able to tell if the female has fed by sensing chemicals in the web. ''Latrodectus hesperus
''Latrodectus hesperus'', the western black widow spider or western widow, is a venomous spider species found in western regions of North America. The female's body is 14–16 mm (1/2 in) in length and is black, often with an hourglass-shape ...
'' is referred to as an "opportunistic cannibal" because in dire situations it will resort to cannibalism. In addition to sexual cannibalism, ''Latrodectus hesperus'' are also known to engage in sibling cannibalism.
Like other members of the Theridiidae, widow spiders construct a web of irregular, tangled, sticky silken fibres. Black widow spiders prefer to nest near the ground in dark and undisturbed areas, usually in small holes produced by animals, or around construction openings or woodpiles. Indoor nests are in dark, undisturbed places such as under desks or furniture or in a basement. The spider frequently hangs upside down near the centre of its web and waits for insects to blunder in and get stuck. Then, before the insect can extricate itself, the spider rushes over to envenomate and wrap it in silk. To feed, the spider's mouth pulses digestive juice
Gastric acid, gastric juice, or stomach acid is a digestive fluid formed within the stomach lining. With a pH between 1 and 3, gastric acid plays a key role in digestion of proteins by activating digestive enzymes, which together break down the ...
s over the prey, which liquifies, which the spider internalizes by capillary action
Capillary action (sometimes called capillarity, capillary motion, capillary rise, capillary effect, or wicking) is the process of a liquid flowing in a narrow space without the assistance of, or even in opposition to, any external forces li ...
, sucking the slurry into its mouth. Their prey consists of small insects such as flies, mosquitoes, grasshoppers, beetles, and caterpillars. If the spider perceives a threat, it quickly lets itself down to the ground on a safety line of silk.
As with other web-weavers, these spiders have very poor eyesight and depend on vibrations reaching them through their webs to find trapped prey or warn them of larger threats. When a widow spider is trapped, it is unlikely to bite, preferring to play dead or flick silk at the potential threat; bites occur when they cannot escape. Many injuries to humans are due to defensive bites delivered when a spider gets unintentionally squeezed or pinched. The blue mud dauber species, '' Chalybion californicum'', is a wasp that, in western North America, is the primary predator of black widow spiders.
The ultimate tensile strength
Ultimate tensile strength (UTS), often shortened to tensile strength (TS), ultimate strength, or F_\text within equations, is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials t ...
and other physical properties of ''Latrodectus hesperus
''Latrodectus hesperus'', the western black widow spider or western widow, is a venomous spider species found in western regions of North America. The female's body is 14–16 mm (1/2 in) in length and is black, often with an hourglass-shape ...
'' (western black widow) silk are similar to the properties of silk from orb-weaving spider
Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name ...
s that had been tested in other studies. The tensile strength for the three kinds of silk measured in the Blackledge study was about 1,000 MPa. The ultimate strength reported in a previous study for ''Trichonephila edulis
''Trichonephila edulis'' is a species of large spider of the family Araneidae, formerly placed in the genus ''Nephila''. It is referred to the common name Australian golden orb weaver. It is found in Indonesia from Java eastwards, Papua New Gui ...
'' was 1,290 ± 160 MPa. The tensile strength of spider silk is comparable to that of steel wire of the same thickness. However, as the density of steel is about six times that of silk, silk is correspondingly stronger than steel wire of the same weight.
Spiders of the genus '' Steatoda'' (also of the Theridiidae) are often mistaken for widow spiders, and are known as "false widow spider
The spider genus ''Steatoda'', in the family Theridiidae, includes about 120 recognized species, distributed around the world (including many cosmopolitan species which are found among human populations worldwide). One common name is cupboard spi ...
s"; while their bite can be painful, they are significantly less harmful to humans.
Taxonomy
The genus ''Latrodectus'' was erected by Charles Athanase Walckenaer
Baron Charles Athanase Walckenaer (25 December 1771 – 28 April 1852) was a French civil servant and scientist.
Biography
Walckenaer was born in Paris and studied at the universities of University of Oxford, Oxford and University of Glasgow ...
in 1805, for the species ''Latrodectus tredecimguttatus
''Latrodectus tredecimguttatus'', also known as the Mediterranean black widow, or the European black widow, is a species in the genus ''Latrodectus'' of the widow spiders. It is commonly found throughout the Mediterranean region, ranging from ...
'' and ''Latrodectus mactans
''Latrodectus mactans'', known as southern black widow or simply black widow, and the shoe-button spider, is a venomous species of spider in the genus ''Latrodectus''. The females are well known for their distinctive black and red coloring and f ...
''. Arachnologist Herbert Walter Levi Herbert Walter Levi (January 3, 1921 – November 3, 2014) was professor emeritus of zoology and curator of arachnology at the Museum of Comparative Zoology, Harvard University. He was born in Germany, educated there and at Leighton Park School, Rea ...
revised the genus in 1959, studying the female sexual organs and noting their similarity across described species. He concluded the colour variations were variable across the world and were not sufficient to warrant species status, and reclassified the redback and several other species as subspecies of the black widow spider.
Levi also noted that study of the genus had been contentious; in 1902, both F. O. Pickard-Cambridge and Friedrich Dahl
Karl Friedrich Theodor Dahl (June 24, 1856 in Rosenhofer Brök north of Dahme, Holstein – June 29, 1929 in Greifswald) was a German zoologist, and in particular an arachnologist.
The son of a farmer, Dahl studied at the universities of Leipzi ...
had revised the genus, with each criticising the other. Cambridge questioned Dahl's separating species on what he considered minor anatomical details, and the latter dismissed the former as an "ignoramus".
Species
the World Spider Catalog
The World Spider Catalog (WSC) is an online searchable database concerned with spider taxonomy. It aims to list all accepted families, genera and species, as well as provide access to the related taxonomic literature. The WSC began as a series of ...
accepted the following species:[
*'' Latrodectus antheratus'' (Badcock, 1932) – ]Paraguay
Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...
, Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
*''Latrodectus apicalis
''Latrodectus apicalis'', known as the Galapagos black widow, is endemic to the Galápagos Islands
The Galápagos Islands ( Spanish: , , ) are an archipelago of volcanic islands. They are distributed on each side of the equator in the P ...
'' Butler
A butler is a person who works in a house serving and is a domestic worker in a large household. In great houses, the household is sometimes divided into departments with the butler in charge of the dining room, wine cellar, and pantry. Some a ...
, 1877 – Galapagos Islands
*''Latrodectus bishopi
''Latrodectus bishopi'' is the scientific name for the red widow spider, which is endemic to certain habitats of central and southern Florida, where it lives primarily in sand dunes dominated by sand pine, ''Pinus clausa'' – a type of vegetati ...
'' Kaston, 1938 – USA
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
*''Latrodectus cinctus
''Latrodectus cinctus'' is a species of spider in the family Theridiidae, found in Cape Verde Islands, Africa, Kuwait and Iran. It is one of six species of ''Latrodectus'' found in southern Africa, four of which, including ''L. cinctus'', ar ...
'' Blackwall, 1865 – Cape Verde Is., Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
, Kuwait
Kuwait (; ar, الكويت ', or ), officially the State of Kuwait ( ar, دولة الكويت '), is a country in Western Asia. It is situated in the northern edge of Eastern Arabia at the tip of the Persian Gulf, bordering Iraq to the nort ...
, Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
*''Latrodectus corallinus
''Latrodectus corallinus'' is a species of widow spider native to Argentina. It is approximately in size, and is primarily black with large, red markings on its abdomen, as well as a red, square-like ring under its abdomen.
Distribution and h ...
'' Abalos, 1980 – Argentina
*''Latrodectus curacaviensis
''Latrodectus curacaviensis'' is a species of black widow spider, that belongs to the genus ''Latrodectus''. It is known as the South American black widow, Brazilian black widow or Araña del trigo.
Description
Like many black widow species, f ...
'' (Müller, 1776) – Lesser Antilles
The Lesser Antilles ( es, link=no, Antillas Menores; french: link=no, Petites Antilles; pap, Antias Menor; nl, Kleine Antillen) are a group of islands in the Caribbean Sea. Most of them are part of a long, partially volcanic island arc betwe ...
, South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southe ...
*'' Latrodectus dahli'' Levi
Levi (; ) was, according to the Book of Genesis, the third of the six sons of Jacob and Leah (Jacob's third son), and the founder of the Israelite Tribe of Levi (the Levites, including the Kohanim) and the great-grandfather of Aaron, Moses and M ...
, 1959 – North Africa, Cyprus
Cyprus ; tr, Kıbrıs (), officially the Republic of Cyprus,, , lit: Republic of Cyprus is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. Its continental position is disputed; while it is geo ...
, Turkey
Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a list of transcontinental countries, transcontinental country located mainly on the Anatolia, Anatolian Peninsula in Western Asia, with ...
, Azerbaijan
Azerbaijan (, ; az, Azərbaycan ), officially the Republic of Azerbaijan, , also sometimes officially called the Azerbaijan Republic is a transcontinental country located at the boundary of Eastern Europe and Western Asia. It is a part of th ...
, Kazakhstan
Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...
, Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabian Peninsula, Arabia (including the Arabian Peninsula and Bahrain), Anatolia, Asia Minor (Asian part of Turkey except Hatay Pro ...
, Iran, Central Asia
Central Asia, also known as Middle Asia, is a subregion, region of Asia that stretches from the Caspian Sea in the west to western China and Mongolia in the east, and from Afghanistan and Iran in the south to Russia in the north. It includes t ...
*'' Latrodectus diaguita'' Carcavallo, 1960 – Argentina
*'' Latrodectus elegans'' Thorell, 1898 – India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
, Myanmar
Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...
, Thailand
Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is bo ...
, China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
, Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
*''Latrodectus erythromelas
''Latrodectus erythromelas'', is a species of venomous spider of the genus ''Latrodectus'', commonly called widow spiders. It is native to India and Sri Lanka.
Description
Female is larger than male, and the average total length is about 8.8mm. ...
'' Schmidt
Schmidt may refer to:
* Schmidt (surname), including list of people with the surname
* Schmidt (singer) (born 1990), German pop and jazz singer
* Schmidt (lunar crater), a small lunar impact crater
* Schmidt (Martian crater), a List of craters on ...
& Klaas, 1991 – India, Sri Lanka
Sri Lanka (, ; si, ශ්රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...
*'' Latrodectus garbae'' Rueda & Realpe, 2021 – Colombia
Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...
*''Latrodectus geometricus
''Latrodectus geometricus'', commonly known as the brown widow, brown button spider, grey widow, brown black widow, house button spider or geometric button spider, is one of the widow spiders in the genus ''Latrodectus''. As such, it is a 'cousi ...
'' C. L. Koch, 1841 – Africa. Introduced to both Americas, Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...
, Middle East, Pakistan
Pakistan ( ur, ), officially the Islamic Republic of Pakistan ( ur, , label=none), is a country in South Asia. It is the world's List of countries and dependencies by population, fifth-most populous country, with a population of almost 24 ...
, India, Thailand, Japan, China, Papua New Guinea
Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...
, Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
, Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...
*''Latrodectus hasselti
The redback spider (''Latrodectus hasselti''), also known as the Australian black widow, is a species of highly venomous spider believed to originate in South Australia or adjacent Western Australian deserts, but now found throughout Austral ...
'' Thorell, 1870 – Southeast Asia
Southeast Asia, also spelled South East Asia and South-East Asia, and also known as Southeastern Asia, South-eastern Asia or SEA, is the geographical United Nations geoscheme for Asia#South-eastern Asia, south-eastern region of Asia, consistin ...
to Australia. Introduced to Iran, Pakistan, India, Japan, New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
*''Latrodectus hesperus
''Latrodectus hesperus'', the western black widow spider or western widow, is a venomous spider species found in western regions of North America. The female's body is 14–16 mm (1/2 in) in length and is black, often with an hourglass-shape ...
'' Chamberlin
The Chamberlin is an electro-mechanical keyboard instrument that was a precursor to the Mellotron. It was developed and patented by the American inventor Harry Chamberlin from 1949 to 1956, when the first model was introduced. There are severa ...
& Ivie, 1935 – Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
, USA, Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
. Introduced to Israel
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
, Korea
Korea ( ko, 한국, or , ) is a peninsular region in East Asia. Since 1945, it has been divided at or near the 38th parallel, with North Korea (Democratic People's Republic of Korea) comprising its northern half and South Korea (Republic o ...
*'' Latrodectus hurtadoi'' Rueda & Realpe, 2021 – Colombia
*'' Latrodectus hystrix'' Simon
Simon may refer to:
People
* Simon (given name), including a list of people and fictional characters with the given name Simon
* Simon (surname), including a list of people with the surname Simon
* Eugène Simon, French naturalist and the genus ...
, 1890 – Yemen
Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the Saudi Arabia–Yemen border, north and ...
(mainland, Socotra
Socotra or Soqotra (; ar, سُقُطْرَىٰ ; so, Suqadara) is an island of the Republic of Yemen in the Indian Ocean, under the ''de facto'' control of the UAE-backed Southern Transitional Council, a secessionist participant in Yemen’s ...
)
*''Latrodectus indistinctus
''Latrodectus indistinctus'' is a species of spider in the family Theridiidae, found in Namibia and South Africa. It is one of six species of ''Latrodectus'' found in southern Africa, four of which, including ''L. indistinctus'', are known a ...
'' O. Pickard-Cambridge
Octavius Pickard-Cambridge FRS (3 November 1828 – 9 March 1917) was an English clergyman and zoologist. He was a keen arachnologist who described and named more than 900 species of spider.
Life and work
Pickard-Cambridge was born in Blox ...
, 1904 – Namibia
Namibia (, ), officially the Republic of Namibia, is a country in Southern Africa. Its western border is the Atlantic Ocean. It shares land borders with Zambia and Angola to the north, Botswana to the east and South Africa to the south and ea ...
, South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...
*''Latrodectus karrooensis
''Latrodectus karrooensis'' is a species of spider in the family Theridiidae, found in South Africa. It is one of six species of ''Latrodectus'' found in southern Africa, four of which, including ''L. karrooensis'', are known as black button ...
'' Smithers, 1944 – South Africa
*''Latrodectus katipo
''Latrodectus'' is a broadly distributed genus of spiders with several species that are commonly known as the true widows. This group is composed of those often loosely called black widow spiders, brown widow spiders, and similar spiders. Howeve ...
'' Powell, 1871 – New Zealand
*'' Latrodectus lilianae'' Melic, 2000 – Spain
, image_flag = Bandera de España.svg
, image_coat = Escudo de España (mazonado).svg
, national_motto = ''Plus ultra'' (Latin)(English: "Further Beyond")
, national_anthem = (English: "Royal March")
, i ...
, Algeria
)
, image_map = Algeria (centered orthographic projection).svg
, map_caption =
, image_map2 =
, capital = Algiers
, coordinates =
, largest_city = capital
, relig ...
?
*''Latrodectus mactans
''Latrodectus mactans'', known as southern black widow or simply black widow, and the shoe-button spider, is a venomous species of spider in the genus ''Latrodectus''. The females are well known for their distinctive black and red coloring and f ...
'' ( Fabricius, 1775) – Probably native to North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
only. Introduced to South America, Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area ...
*'' Latrodectus menavodi'' Vinson, 1863 – Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
, Comoros
The Comoros,, ' officially the Union of the Comoros,; ar, الاتحاد القمري ' is an independent country made up of three islands in southeastern Africa, located at the northern end of the Mozambique Channel in the Indian Ocean. It ...
, Seychelles
Seychelles (, ; ), officially the Republic of Seychelles (french: link=no, République des Seychelles; Creole: ''La Repiblik Sesel''), is an archipelagic state consisting of 115 islands in the Indian Ocean. Its capital and largest city, V ...
(Aldabra)
*'' Latrodectus mirabilis'' (Holmberg, 1876) – Argentina
*'' Latrodectus obscurior'' Dahl, 1902 – Cape Verde Is., Madagascar
Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...
*''Latrodectus pallidus
''Latrodectus pallidus'' is a species of spider commonly found throughout North Africa, the Middle East, and central Asia. A common name in English is the white widow spider, and it is known in Russian as белый каракурт, or white ste ...
'' O. Pickard-Cambridge, 1872 – Cape Verde Is. to Libya
Libya (; ar, ليبيا, Lībiyā), officially the State of Libya ( ar, دولة ليبيا, Dawlat Lībiyā), is a country in the Maghreb region in North Africa. It is bordered by the Mediterranean Sea to the north, Egypt to Egypt–Libya bo ...
, Turkey, Kazakhstan, Iran, Central Asia
*'' Latrodectus quartus'' Abalos, 1980 – Argentina
*''Latrodectus renivulvatus
''Latrodectus renivulvatus'' is a species of spider in the family Theridiidae, found in Africa, Saudi Arabia and Yemen. It is one of six species of ''Latrodectus'' found in southern Africa, four of which, including ''L. renivulvatus'', are k ...
'' Dahl, 1902 – Africa, Yemen, Saudi Arabia
Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in Western Asia. It covers the bulk of the Arabian Peninsula, and has a land area of about , making it the fifth-largest country in Asia, the second-largest in the A ...
, Iraq
Iraq,; ku, عێراق, translit=Êraq officially the Republic of Iraq, '; ku, کۆماری عێراق, translit=Komarî Êraq is a country in Western Asia. It is bordered by Turkey to Iraq–Turkey border, the north, Iran to Iran–Iraq ...
*'' Latrodectus revivensis'' Shulov, 1948 – Israel
Israel (; he, יִשְׂרָאֵל, ; ar, إِسْرَائِيل, ), officially the State of Israel ( he, מְדִינַת יִשְׂרָאֵל, label=none, translit=Medīnat Yīsrāʾēl; ), is a country in Western Asia. It is situated ...
*''Latrodectus rhodesiensis
''Latrodectus rhodesiensis'' is a species of spider in the family Theridiidae, found in southern Africa. It is one of six species of ''Latrodectus'' found in southern Africa, two of which, including ''L. rhodesiensis'', are known as brown bu ...
'' Mackay, 1972 – Southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of ...
*'' Latrodectus thoracicus'' Nicolet, 1849 – Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
*''Latrodectus tredecimguttatus
''Latrodectus tredecimguttatus'', also known as the Mediterranean black widow, or the European black widow, is a species in the genus ''Latrodectus'' of the widow spiders. It is commonly found throughout the Mediterranean region, ranging from ...
'' (Rossi, 1790) ( type) – Mediterranean, Ukraine
Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inv ...
, Caucasus
The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historically ...
, Russia
Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...
(Europe to South Siberia), Kazakhstan, Iran, Central Asia, China
*''Latrodectus umbukwane
''Latrodectus umbukwane,'' commonly known as the Phinda button spider, is a species of the spider in the genus ''Latrodectus'' described in 2019, named after the Phinda Private Game Reserve where research specimens were collected. , it is known ...
'' B. M. O. G. Wright, C. D. Wright, Lyle & Engelbrecht, 2019 – South Africa
*'' Latrodectus variegatus'' Nicolet, 1849 – Chile, Argentina
*''Latrodectus variolus
''Latrodectus variolus'', the northern black widow spider or northern widow, is a venomous species of spider in the genus ''Latrodectus'' of the family Theridiidae. The population is closely related to the southern black widow, ''Latrodectus mact ...
'' Walckenaer, 1837 – USA, Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
Nomina dubia
In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application.
Zoology
In case of a ''nomen dubium'' it may be impossible to determine whether a s ...
*''L. dotatus'' C. L. Koch, 1841
*''L. limacidus'' Cantor, 1842
*''L. pallidus'' Caporiacco, 1933
Distribution
Widow spiders are found on every continent of the world except Antarctica. In North America, the black widows commonly known as southern (''Latrodectus mactans
''Latrodectus mactans'', known as southern black widow or simply black widow, and the shoe-button spider, is a venomous species of spider in the genus ''Latrodectus''. The females are well known for their distinctive black and red coloring and f ...
''), western (''Latrodectus hesperus
''Latrodectus hesperus'', the western black widow spider or western widow, is a venomous spider species found in western regions of North America. The female's body is 14–16 mm (1/2 in) in length and is black, often with an hourglass-shape ...
''), and northern (''Latrodectus variolus
''Latrodectus variolus'', the northern black widow spider or northern widow, is a venomous species of spider in the genus ''Latrodectus'' of the family Theridiidae. The population is closely related to the southern black widow, ''Latrodectus mact ...
'') are found in the United States, as well as parts of southern Canada – particularly in the Okanagan Valley
The Okanagan ( ), also known as the Okanagan Valley and sometimes as the Okanagan Country, is a region in the Canadian province of British Columbia defined by the basin of Okanagan Lake and the Canadian portion of the Okanagan River. It is part ...
of British Columbia, as can the "grey" or "brown widow spiders" (''Latrodectus geometricus
''Latrodectus geometricus'', commonly known as the brown widow, brown button spider, grey widow, brown black widow, house button spider or geometric button spider, is one of the widow spiders in the genus ''Latrodectus''. As such, it is a 'cousi ...
'') and the "red widow spiders" (''Latrodectus bishopi
''Latrodectus bishopi'' is the scientific name for the red widow spider, which is endemic to certain habitats of central and southern Florida, where it lives primarily in sand dunes dominated by sand pine, ''Pinus clausa'' – a type of vegetati ...
'').
The most prevalent species occurring in eastern Asia and Australia is commonly called the redback (''Latrodectus hasselti
The redback spider (''Latrodectus hasselti''), also known as the Australian black widow, is a species of highly venomous spider believed to originate in South Australia or adjacent Western Australian deserts, but now found throughout Austral ...
'').
They are often confused with spiders in the genus '' Steatoda'', known as false widow spiders, due to their similar appearance.
Venom
Due to the presence of latrotoxin
A latrotoxin is a high-molecular mass neurotoxin found in the venom of spiders of the genus ''Latrodectus'' (widow spiders) as well as at least one species of another genus in the same family, '' Steatoda nobilis''. Latrotoxins are the main activ ...
in their venom, black widow bites are potentially dangerous and may result in systemic effects (latrodectism
Latrodectism () is the illness caused by the bite of ''Latrodectus'' spiders (the black widow spider and related species). Pain, muscle rigidity, vomiting, and sweating are the symptoms of latrodectism.
There are several spider species all named b ...
) including severe muscle pain, abdominal cramps, hyperhidrosis
Hyperhidrosis is a condition characterized by abnormally increased sweating, in excess of that required for regulation of body temperature. Although primarily a benign physical burden, hyperhidrosis can deteriorate quality of life from a psychologi ...
, tachycardia
Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal (su ...
, and muscle spasms. Symptoms usually last for 3–7 days, but may persist for several weeks. In 1933, a University of Alabama
The University of Alabama (informally known as Alabama, UA, or Bama) is a Public university, public research university in Tuscaloosa, Alabama. Established in 1820 and opened to students in 1831, the University of Alabama is the oldest and la ...
medical faculty, Allan Blair
Allan Walker Blair (1900–1948) was a professor at the University of Alabama's medical school who is best known for allowing himself to be bitten by a black widow spider in order to investigate the toxicity of its venom in humans. As a result of t ...
conducted an experiment on himself to document the symptoms of a black widow bite, and to test whether someone can build immunity after being bitten. The effects of the bite were so painful and harsh that Blair failed to complete the experiment and did not follow through with being bitten a second time.
In the United States each year, about 2,200 people report being bitten by a black widow, but most do not need medical treatment. Some bites have no venom injected—a "dry" bite. In the United States, no deaths due to black widows have been reported to the American Association of Poison Control Centers since 1983. Black widows are not especially aggressive spiders, and they rarely bite humans unless startled or otherwise threatened.
Contrary to popular belief, most people who are bitten suffer no serious damage, let alone death. Fatal bites were reported in the early 20th century mostly with ''Latrodectus tredecimguttatus
''Latrodectus tredecimguttatus'', also known as the Mediterranean black widow, or the European black widow, is a species in the genus ''Latrodectus'' of the widow spiders. It is commonly found throughout the Mediterranean region, ranging from ...
'', the Mediterranean black widow.
Since the venom is not usually life-threatening, antivenom
Antivenom, also known as antivenin, venom antiserum, and antivenom immunoglobulin, is a specific treatment for envenomation. It is composed of antibodies and used to treat certain venomous bites and stings. Antivenoms are recommended only if th ...
has been used as pain relief
Pain management is an aspect of medicine and health care involving relief of pain (pain relief, analgesia, pain control) in various dimensions, from acute and simple to chronic and challenging. Most physicians and other health professionals pr ...
and not to save lives. However, a study demonstrated that standardized pain medication
An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of drugs used to achieve relief from pain (that is, analgesia or pain management). It i ...
, when combined with either antivenom or a placebo, had similar improvements in pain and resolution of symptoms.
See also
* List of spiders associated with cutaneous reactions
A spider bite, also known as arachnidism, is an injury resulting from the bite of a spider. The effects of most bites are not serious. Most bites result in mild symptoms around the area of the bite. Rarely they may produce a necrotic skin wound ...
References
Further reading
*
*
*
*
*
External links
Tree of Life: ''Latrodectus''
Description of crossing experiments between various ''Latrodectus'' species
on the UF / IFAS Featured Creatures Web site
{{Authority control
Araneomorphae genera
Cosmopolitan spiders
Venomous arthropods