Button spider is a

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 ...

used in

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 ...

to refer to local members of the

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 ...

genus, ''

Latrodectus ''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 ...

'', 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 ...

. There are both black and brown button spiders in Southern Africa, that are known elsewhere as widow spiders. Seven ''Latrodectus'' species can be found in Southern Africa; six of them are native, one is possibly imported.

Venom

All species of ''Latrodectus'' are venomous to humans, and their bite constitutes a

medical emergency A medical emergency is an acute injury or illness that poses an immediate risk to a person's life or long-term health, sometimes referred to as a situation risking "life or limb". These emergencies may require assistance from another, qualified p ...

. Envenomation by these spiders can be fatal to children and ill or infirm adults but there has never been a documented fatality from any button spider species in Southern Africa. Ordinarily, the body mass of a healthy adult is sufficient to dilute the venom to less than a fatal concentration. In most species, only the female spider is capable of effectively delivering the venom to humans as the males have much smaller

chelicerae The chelicerae () are the mouthparts of the subphylum Chelicerata, an arthropod group that includes arachnids, horseshoe crabs, and sea spiders. Commonly referred to as "jaws", chelicerae may be shaped as either articulated fangs, or similarly ...

. Although rarely fatal, the symptoms of the bite are often incredibly painful and medical attention is recommended following any ''Latrodectus'' species bite, as complications relating to the bite can arise. Treatment of bites is usually supportive, administering

opiates An opiate, in classical pharmacology, is a substance derived from opium. In more modern usage, the term ''opioid'' is used to designate all substances, both natural and synthetic, that bind to opioid receptors in the brain (including antagonist ...

for pain and

benzodiazepines Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, i ...

for spasms. An antidote is available in

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 ...

for the bites of both ''L. indistinctus'' and ''L. geometricus'', however it is only used for severe cases of envenomation due to its potentially severe side effects.http://ewhighered.mcgraw-hill.com/sites/dl/free/0071437630/358186/goldfrank_toxicology_chap115a.pdf{{Dead link, date=October 2019 , bot=InternetArchiveBot , fix-attempted=yes Individuals who are allergic to the venom may also require

epinephrine Adrenaline, also known as epinephrine, is a hormone and medication which is involved in regulating visceral functions (e.g., respiration). It appears as a white microcrystalline granule. Adrenaline is normally produced by the adrenal glands and ...

(adrenaline) or

diphenhydramine Diphenhydramine (DPH) is an antihistamine and sedative mainly used to treat allergies, insomnia, and symptoms of the common cold. It is also less commonly used for tremor in parkinsonism, and nausea. It is taken by mouth, injected into a vein ...

to treat subsequent

anaphylaxis Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the follow ...

Button spider species

The species are informally divided into two groups, based on their color: The black button spiders are black or brown in color, and include the following species: * '' L. cinctus'' (east coast button spider) * '' L. indistinctus'' (west coast button spider) * '' L. karooensis'' (

Karoo The Karoo ( ; from the Afrikaans borrowing of the South Khoekhoe !Orakobab or Khoemana word ''ǃ’Aukarob'' "Hardveld") is a semi-desert natural region of South Africa. No exact definition of what constitutes the Karoo is available, so its ext ...

button spider) * '' L. renivulvatus'' (inland button spider) All of these spiders are native to Southern Africa. The brown button spiders are lighter in color than the black button spiders and have a red hourglass marking under the abdomen (not above) with exception of the L. umbukwane which has both red markings above and below the opisthosoma (abdomen); there are three brown button species: * '' L. geometricus'' (brown button spider) * '' L. rhodesienses'' (Zimbabwe button spider) * '' L. umbukwane'' (Phinda button spider) ''L. geometricus'' is found in many parts of the world,(including in the

United States 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 territorie ...

) and it is known as the

brown widow spider ''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 ...

. it is unknown where this species' origins are. ''L. rhodesienses'' is native to Africa. Both brown button species have the famed hourglass markings of the black widow from other countries on their abdomens, but are generally lighter in colour. The brown button spiders' venom is less toxic to humans than the venom of the black buttons.

References

External links

Ansie Dippenaar-Schoeman: The button spiders of southern Africa

* Spiders of Africa Arthropod common names nl:Weduwen#Weduwen uit Subsaharisch Afrika en Madagaskar Recent edit introducing L. umbukwane: Marty Wright