- Open Access
First report of brown widow spider sightings in Peninsular Malaysia and notes on its global distribution
© Muslimin et al.; licensee BioMed Central. 2015
Received: 11 August 2014
Accepted: 27 April 2015
Published: 9 May 2015
The brown widow spider (Latrodectus geometricus Koch, 1841) has colonised many parts of the world from its continent of origin, Africa. By at least 1841, the species had successfully established populations in South America and has more recently expanded its range to the southern states of North America. This highly adaptable spider has been far more successful in finding its niche around the world than its famous cousins, the black widow, Latrodectus mactans, found in the south-eastern states of North America, and the red-back, Latrodectus hasselti, found mostly in Australia, New Zealand and Japan.
We performed an extensive web search of brown widow sightings and mapped the location of each sighting using ArcGIS. Specimens reputedly of the species L. geometricus were collected at three localities in Peninsular Malaysia. The spiders were identified and documented based on an examination of morphological characteristics and DNA barcoding.
The spiders found in Peninsular Malaysia were confirmed to be Latrodectus geometricus based on their morphological characteristics and DNA barcodes. We recorded 354 sightings of the brown widow in 58 countries, including Peninsular Malaysia.
Reports from the Americas and the Far East suggest a global-wide invasion of the brown widow spider. Herein we report the arrival of the brown widow spider in Peninsular Malaysia and provide notes on the identification of the species and its recently expanded range.
The widow spiders comprise 30 species in the genus Latrodectus Walckenaer, 1805 . They earned the name “widow” because the female eats the male after mating. However, this behavior has been only conclusively documented for one species, the red-back spider (L. hasselti Thorell, 1870) . Black widow [L. mactans, (Fabricius 1775)] envenomation can cause death in humans; however, lethality is less than 1% [3,4]. Human mortality caused by the red-back spider, native to Australia and New Zealand, has never been reported, perhaps in part because these two countries have an extensive supply of antivenom [5,6]. Human death resulting from envenomation by the lesser-known brown widow (L. geometricus Koch, 1841) was reported in Madagascar in 1991. However, the identity of the spider, consequences of delayed medical intervention and the exact details of the case, whose report is in French, remain in question . Furthermore, medical conditions associated with spider bites are often over-diagnosed and misdiagnosed . The brown widow is known by many arachnologists to be nonaggressive and usually bites only when threatened. Like most widow spiders, it avoids people and prefers the shelter of its protective retreat. If the retreat is disturbed, the spider often jumps from its web to the ground, retracts its legs and plays dead, in a behavior known as thanatosis .
Reports from the Americas to the Far East suggest a recent global-wide invasion of the brown widow spider and numerous sightings of brown widows have been reported in Central Asia and the Middle East [10-16]. The Department of Parasitology at the University of Malaya Faculty of Medicine, Kuala Lumpur, is monitoring this invasion and is contacted periodically by concerned local citizens reporting unusual spiders in their homes. These concerns are likely unwarranted since only one single case of a venomous spider (Lampropelma violaceopedes Abraham, 1924) biting a human has been reported in Southeast Asia . However, rapid urbanization in East Asia and the region’s bustling economic trade and growing population may promote colonization by synanthropic widow spiders as specimens “hitchhike” in containers to densely populated areas [1,18,19]. This paper reports the arrival of the brown widow spider in Peninsular Malaysia and provides notes on the identification of the species and its global distribution.
Global distribution of Latrodectus geometricus
Global records of L. geometricus were compiled from the scientific literature and popular media through web searches, together with GPS coordinates obtained directly from the records or inferred as precisely as possible from the stated locations. These records were then mapped using ArcGIS 9.2 .
Latrodectus geometricus in Peninsular Malaysia
Acting on calls from the general public, spider specimens reputedly of the species L. geometricus were collected at three localities in Peninsular Malaysia: Penang (5°24′00″N, 100°14′20″E), at a private residence after obtaining permission from the owners; on the roadside, near food stalls in a residential area in Selangor (3°20′N, 101°30′E); and in a private vehicle in Johor (1°29′14″N, 103°46′52″E) after obtaining the permission of the vehicle owner. Permission to collect spiders in Peninsular Malaysia was approved by the Department of Wildlife and National Parks of Peninsular Malaysia, commonly known as PERHILITAN (application number: JPHL&TN(IP): 80-4/2 Jld16).
Spiders were provisionally identified by examining the palps, epigynum, geometrical markings on the underside of the abdomen and spherical spikey off-white egg sacs . As a member of the family Theridiidae, L. geometricus has four pairs of eyes positioned in two parallel rows, a comb feet arranged in a comb-like row of bristles on the tarsi of the hind legs, and distinctive paired spermathecae with coiled copulatory ducts [21-24]. Similarly to some other widow spiders, brown widows have a characteristic hourglass-shaped streak on the underside of the abdomen which varies from a pale to dark orange as the spider matures. Females are significantly larger than males (leg length 30-40 mm compared with 16-20 mm in males).
DNA was extracted from whole spiders using a NucleoSpin tissue kit (Macherey-Nagel) following the procedures recommended by the manufacturer. We PCR-amplified the “DNA barcode” fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene (mtDNA) using the primer combination LepF1/LepR1 and standard thermocycling conditions . The PCR product was sequenced in both directions using the PCR primers by a local company (MyTACG Bioscience, Kuala Lumpur). The resulting sequences were edited and combined with all COI sequences from Latrodectus available on the GenBank and analyzed using the neighbor-joining method and MEGA 6 software . The DNA sequences and associated information about the specimens (photographs, collection date and locality) can be found in the public dataset DS-LATRO on the Barcode of Life Datasystems’ (BOLD) website (http://www.boldsystems.org), and also on GenBank (http://www.ncbi.nlm.nih.gov/genbank; accession numbers: KF227386-KF227396).
Although the description of this species is based on a specimen collected in Colombia, South America in 1841, Latrodectus geometricus is thought to be native to southern Africa and to have gradually expanded its range since the 1800s to cover both tropical and temperate regions of the world (Figure 1) . Sightings of brown widows had already been reported in South America, North America, and the Middle East (Yemen in 1890) before 1900 [28,32,88]. Since then, sightings were reported in Saudi Arabia in 1959, Israel in 1983, Central Asia (Afghanistan in 2008 and Turkey in 2008), Southeast Asia (Indonesia in 1950, the Philippines in 1950 and Singapore in 2006), Japan in 1995, and Australia in 1987 [15,51,52,73,75,80,86,95,107]. Although the presence of the brown widow has yet to be reported in Europe, with the exception of Turkey, the species is extending its range into temperate North America with recent reports from southern US states such as Texas, North Carolina and Mississippi .
Although the L. geometricus specimens found in Peninsular Malaysia were easily identifiable due to their morphological characteristics, the findings were confirmed using DNA barcoding. The brown widows collected in the northwest (Penang) and south (Johor) of Peninsular Malaysia seemed to be morphologically similar to those reported in port cities in Japan, suggesting that Japan is the source of the infestation . This would not be surprising, given the amount of trade between Japan and these two ports . Penang is an international port, popularly known as the Pearl of the Orient, and therefore we suspect that L. geometricus was accidentally imported.
Upon arrival, L. geometricus is known to colonize urban areas especially in and around homes and gardens, which is consistent with our observations of brown widow webs and eggs in both well-lit and dark areas around windows, ceilings and car door hinges [1,48,78,130]. Since Latrodectus geometricus was reported in Singapore, the proximity of Singapore and Johor suggests that the brown widow collected in Johor may have come from the former, whose population is likely to have originated in Japan . The L. geometricus colony from Selangor (central Peninsular Malaysia) appeared to have two different morphotypes. However, no genetic differentiation was found in their DNA barcodes. The first was similar to those found in Penang and Johor, while the second had a spherical abdomen and was more similar to the brown widow reported in India and Brazil . Phylogeographic studies of different gene regions together with searches for L. geometricus in other localities may shed some light on these findings. Following recent reports from South and North America, Peninsular Malaysia is the latest region to be occupied by the global invasion of the brown widow.
The brown widow spider remains a potential concern and should be monitored. Reports from the Americas and the Far East suggest a global-wide invasion of the brown widow spider due to its far-reaching adaptability. The arrival of the brown widow spider in Peninsular Malaysia including identification of the species using both taxonomic and molecular methods was reported. Furthermore, its recently expanded range and its phylogeographic distribution were discussed in view of its impact on humans.
Ethics committee approval
Permission to collect samples was granted by the Department of Wildlife and National Parks, Peninsular Malaysia (PERHILITAN): application number JPHL&TN(IP): 80-4/2 Jld16(24). This consent prohibits the collection of endangered or protected species.
Authors were awarded University of Malaya Research Grants (RG301/11HTM to WSW, and RG509-13HTM to NMAA) and Fundamental Research Grants from the Malaysian Ministry of Higher Education (FP013/2010A to WSW, and FP036/2010A to RM). KAB was supported by the University of Malaya Postgraduate Research Fund (PV052/2012A) and research assistantship High Impact Research Grant (UM.C/625/1/HIR/148/2). JJ was awarded a research assistantship (RG509-13HTM). The funders played no part study design, data collection and analysis, decision to publish, or preparation of the manuscript. The corresponding author, Noraishah Mydin Abdul-Aziz, had full access to all study data and had final responsibility for the decision to submit for publication.
- Garb JE, González A, Gillespie RG. The black widow spider genus Latrodectus (Araneae: Theridiidae): phylogeny, biogeography, and invasion history. Mol Phylogenet Evol. 2004;31(3):1127–42.PubMedGoogle Scholar
- Segoli M, Arieli R, Sierwald P, Harari AR, Lubin Y. Sexual cannibalism in the brown widow spider (Latrodectus geometricus). Ethology. 2008;114(3):279–86.Google Scholar
- Gaisford K, Kautz DD. Black widow spider bite: a case study. Dimens Crit Care Nurs. 2011;30(2):79–86.PubMedGoogle Scholar
- Clark RF, Wethern-Kestner S, Vance MV, Gerkin R. Clinical presentation and treatment of black widow spider envenomation: a review of 163 cases. Ann Emerg Med. 1992;21(7):782–7.PubMedGoogle Scholar
- Sutherland SK, Trinca JC. Survey of 2144 cases of red-back spider bites: Australia and New Zealand, 1963–1976. Med J Aust. 1978;2(14):620–3.PubMedGoogle Scholar
- Bonnet MS. The toxicology of the Latrodectus hasselti spider–the Australian red back spider. Br Homoeopath J. 1999;88(1):2–6.Google Scholar
- Ramialiharisoa A, de Haro L, Jouglard J, Goyffon M. Latrodectism in Madagascar. Med Trop (Mars). 1994;54(2):127–30.Google Scholar
- Diaz JH. The global epidemiology, syndromic classification, management, and prevention of spider bites. Am J Trop Med Hyg. 2004;71(2):239–50.PubMedGoogle Scholar
- Vetter RS. Spiders of the genus Loxosceles (Araneae, Sicariidae): a review of biological, medical and psychological aspects regarding envenomations. J Arachnol. 2008;36(1):150–63.Google Scholar
- Yoshida T. Distribution of Latrodectus geometricus in Japan. Med Entomol Zool. 2003;53 Suppl:62. (in Japanese).Google Scholar
- Vetter RS, Vincent LS, Danielsen DW, Reinker KI, Clarke DE, Itnyre AA, et al. The prevalence of brown widow and black widow spiders (Araneae: Theridiidae) in urban southern California. J Med Entomol. 2012;49(4):947–51.PubMedGoogle Scholar
- Simó M, Dias MFR, Jorge C, Castro M, Dias MA, Laborda A. Habitat, redescription and distribution of Latrodectus geometricus in Uruguay (Araneae: Theridiidae). Biota Neotropica. 2013;13(1):371–5.Google Scholar
- Borkan J, Gross E, Lubin Y, Oryan I. An outbreak of venomous spider bites in a citrus grove. Am J Trop Med Hyg. 1995;52(3):228–30.PubMedGoogle Scholar
- Jiang L, Peng L, Chen J, Zhang Y, Xiong X, Liang S. Molecular diversification based on analysis of expressed sequence tags from the venom glands of the Chinese bird spider Ornithoctonus huwena. Toxicon. 2008;51(8):1479–89.PubMedGoogle Scholar
- Lamb L, Ross D, Lalloo DG, Green A, Morgan E, Warrell DA. Management of venomous bites and stings in British Military Personnel deployed in Iraq, Afghanistan and Cyprus. J R Army Med Corps. 2008;154(Supp 4):2–40.PubMedGoogle Scholar
- Schäfer CN, Nissen LR, Kofoed LT, Hansen FØ. A suspected case of systemic envenomation syndrome in a soldier returning from Iraq: implications for Special Forces Operations. Mil Med. 2010;175(5):375–8.PubMedGoogle Scholar
- Lim B, Davie C. The bite of a bird-eating spider Lempropelma violaceopedes. Med J Malaya. 1970;24(4):311.PubMedGoogle Scholar
- Luniak M. Synurbization - adaptation of animal wildlife to urban development. In: Shaw W, Harris L, Van Druff L, editors. Proceedings of the 4th International Symposium on Urban Wildlife Conservation. Tucson, AZ: College of Agriculture and Life Sciences, University of Arizona; 2004. p. 50–5.Google Scholar
- Brown KS, Necaise JS, Goddard J. Additions to the known US distribution of Latrodectus geometricus (Araneae: Theridiidae). J Med Entomol. 2008;45(5):959–62.PubMedGoogle Scholar
- ESRI. ArcGIS 9.2. Environmental Systems Research Institute Inc Redlands, California; 2006.Google Scholar
- Center for Invasive Species Research (CISR): How to identify Brown Widow Spiders. Riverside: University of California. 2013 http://cisr.ucr.edu/identifying_brown_widow_spiders.html.
- Knoflach B, Pfaller K. Kugelspinnen – eine Einführung (Araneae, Theridiidae). Denisia. 2004;14:111–60.Google Scholar
- Koh JKH, Ming LT. Biodiversity in the Heart of Borneo - Spiders of Brunei Darussalam. Kinabalu: Natural History Publications (Borneo); 2013.Google Scholar
- Levi HW. Cosmopolitan and pantropical species of theridiid spiders (Araneae: Theridiidae). Pac Insects. 1967;9(2):175–86.Google Scholar
- Wilson JJ. DNA barcodes for insects. Methods Mol Biol. 2012;858:17–46.PubMedGoogle Scholar
- Tamura K, Stecher G, Peterson D, Filipski A, Kumar S. MEGA6: molecular evolutionary genetics analysis version 6.0. Mol Biol Evol. 2013;30(12):2725–9.PubMed CentralPubMedGoogle Scholar
- Shukla S, Broome VG. First report of the brown widow spider, Latrodectus geometricus CL Koch (Araneae: Theridiidae) from India. Curr Sci. 2007;93(6):775–7.Google Scholar
- Koch CL. Die Arachniden getreu nach der Natur abgebildet und beschrieben. Nürnberg: C H Zeh'schen Buchhandlung; 1831. p. 1–129.Google Scholar
- Thorell T. On some spiders from New-Caledonia, Madagascar, and Réunion. Proc Zool Soc Lond. 1875:146–8.Google Scholar
- Keyserling E. Die Insektuto. Konchuaikokai. 1884;26:14–8.Google Scholar
- Karsch FAF, Übereinige von Herr JM. Hildebrandt im Zanzibargebiet erbeutete Arachniden. Zeitschrift fur Ges Naturschft. 1878;51(3):311–22.Google Scholar
- Marx G. Catalogue of the described Araneae of temperate North America. Proc US Nat Mus. 1890;12(782):497–594.Google Scholar
- Simon E. Études arachnologiques. 22e Mémoire. XXXV. Etude sur les arachnides recueillis par M. L. von Höhnel, officier de la marine autrichienne, pendant l’expédition de M. le comte Teleki dans l’Afrique orientale équatoriale en 1887–1888. Ann Soc Entomol Fr. 1890:125-130. http://biostor.org/cache/pdf/9f/9b/49/9f9b49419eb2d3d752fb86ba1f8b93ed.pdf.
- Pocock RI. The fauna of British India, Arachnida. London: Taylor and Francis; 1900.Google Scholar
- Cambridge FP. On the spiders of the genus Latrodectus Walckenaer. Proc Zool Soc Lond. 1902;1:247–61.Google Scholar
- Cambridge OP. Descriptions of some new species, and characters of three new genera, of Araneidea from South Africa. Ann S Afr Mus. 1904;5(3):143–66.Google Scholar
- Strand E. Arachniden aus Madagaskar, gesammelt von Herrn Walter Kaudern. (Pseudoscorpiones by Edv. Ellingsen). Zool Jahrb Abt Anat Ontog Tiere. 1908;26:453–88.Google Scholar
- Pocock R. Arthropoda. Arachnida. Scorpions and spiders. In: Forbes HO, editor. The natural history of Sokotra and Abd-el-Kur. Bull Liverpool Mus (Special Bulletin). 1903. p. 209–32.Google Scholar
- Berland L. Araignées. In: Voyage de M. le Baron de Rothschild en Ethiopie et en Afrique orientale anglaise (1904-1905). Résultats scientifiques. Animeux articulés. Paris. 1922;1:43–90.Google Scholar
- Carbonell J. Algunos datos sobre las arañas del género Latrodectus que se hallan en la Argentina. Physis. 1923;6:350–3.Google Scholar
- Reimoser E. Einheimische Spinnen 1 & 2. Die Natur (Wien). 1928;4(5):103–8.Google Scholar
- Chamberlin RV, Woodbury AM. Notes on the spiders of Washington County. Utah Proc Biol Soc Wash. 1929;42:131–42.Google Scholar
- Petrunkevitch A. The spiders of Porto Rico, part 1. Trans Conn Acad Arts Sci. 1929;30:1–158.Google Scholar
- Petrunkevitch A. The spiders of Porto Rico, part 2. Trans Conn Acad Arts Sci. 1930;30:159–356.Google Scholar
- Pearson JF. Latrodectus geometricus Koch in southern Florida. Science. 1936;83:522–3.PubMedGoogle Scholar
- Vellard J. Le venin des araignées. Paris: Masson et Cie; 1936.Google Scholar
- Roewer CF. Katalog der Araneae von 1758 bis 1940, vol. 1. Natura: Bremen, Bruxelles; 1942.Google Scholar
- Smithers RHN. Contributions to our knowledge of the genus Latrodectus (Araneae) in south Africa. Ann S Afr Mus. 1944;36:263–312.Google Scholar
- Bianchi FA. Notes on the abundance of the spiders Latrodectus mactans, L. geometricus and Argiope avara, and of their parasites on the Island of Hawaii. Proc Hawaiian Entomol Soc. 1945;12(2):245–7.Google Scholar
- Caporiacco DL. Aracnidi della Colonia del Kenya raccolti da Toschi e Meneghetti negli anni 1944-1946. Commentat Pontif Acad Scient. 1949;13(6):309–17.Google Scholar
- Keegan HL, Blauw AS, Anderson RI. Latrodectus geométricas Koch on Luzon. Am J Trop Med Hyg. 1950;30(6):901–7.PubMedGoogle Scholar
- Roza M, Soedibio R. Latrodectus hasselti Thorell. Hemera Zoa. 1950;58:169–70.Google Scholar
- Baerg WJ. The brown widow and the black widow spiders in Jamaica (Araneae, Theridiidae). Ann Entomol Soc Am. 1954;47(1):52–60.Google Scholar
- Bouillon A. La fécondité chez l'araignée Latrodectus geometricus C. Koch. Leopoldville: Éditions de l'Université; 1957.Google Scholar
- Levi HW. The spider genus Latrodectus (Araneae, Theridiidae). Trans Am Microsc Soc. 1959;78(1):7–43.Google Scholar
- Abalos JW, Baez EC. On spermatic transmission in spiders. Psyche. 1963;70(4):197–207.Google Scholar
- Chrysanthus P. Spiders from south New Guinea V. Nova Guinea (NS, Zool). 1963;24:727–50.Google Scholar
- Bucherl W. Distribuição geografica dos aracnoides peçonhentos temiveis. Mem Inst Butantan. 1964;31:55–66.Google Scholar
- Gerschman BS, Schiapelli RD. El genero Latrodectus Walckenaer 1805 en la Argentina. Rev Soc Ent Arg. 1965;27:51–9.Google Scholar
- McCrone JD, Stone KJ. The widow spiders of Florida, vol. 2. Florida: Division of Plant Industry; 1965 [Series: Arthropods of Florida and neighboring land areas].Google Scholar
- Abalos JW, Báez EC. Las arañas del genero Latrodectus en Santiago del Estero. Cordoba: Universidad Nacional de Cordoba; 1967 [Série Ciências Naturales N. 55].Google Scholar
- Abalos JW, Baez EC. The spider genus Latrodectus in Santiago del Estero, Argentina. Animal Toxins. Oxford: Pergamon Press; 1967. p. 59–74.Google Scholar
- Pinter LJ. Species of widow spiders in northern Argentina (Latrodectus: Theridiidae). Psyche. 1967;74(4):290–8.Google Scholar
- Abalos JW. La transferencia espermática en los arácnidos. Rev Univ Nac Córdoba. 1968;9(1-2):251–78.Google Scholar
- Lamoral BH. On the nest and web structure of Latrodectus in South Africa, and some observations on body colouration of L. geometricus (Araneae: Theridiidae). Ann Natal Mus. 1968;20(1):1–14.Google Scholar
- Levi HW, Levi LR. A guide to spiders and their kin. New York: Golden Press; 1968.Google Scholar
- Zumpt F. Latrodectism in south Africa. S Afr Med J. 1968;42(16):385–90.PubMedGoogle Scholar
- Kaston BJ. Comparative biology of American black widow spiders. Trans San Diego Soc Nat Hist. 1970;16(3):33–82.Google Scholar
- Mackay IR. A new species of widow spider (genus Latrodectus) from Southern Africa (Araneae: Theridiidae). Psyche. 1972;79(3):236–42.Google Scholar
- Anderson MP. Notes on the brown widow spider, Latrodectus geometricus (Araneae: Theridiidae) in Brazil. Great Lakes Entomol. 1972;5(4):115–8.Google Scholar
- Abalos JW. Las arañas del género Latrodectus en la Argentina. Rev Cent Museo de La Plata. 1980;4(1):29–51.Google Scholar
- Pinter LW. The widow spiders of Hawai'i. In: Smith CW, editor. Proceedings of the Third Conference in Natural Sciences Hawaii Volcanoes National Park; 1980 June 4-6; Honolulu. Honolulu (HI): University of Hawaii at Manoa, Department of Botany; 1980. p. 265.Google Scholar
- Levy G, Amitai P. Revision of the widow-spider genus Latrodectus (Araneae: Theridiidae) in Israel. Zool J Linn Soc. 1983;77:39–63.Google Scholar
- Müller HG. Abgebrochene Emboli in der Vulva der ‘Schwarzen Witwe’Latrodectus geometricus C. L. Koch 1841 (Arachnida: Araneae: Theridiidae). Entomol Z, Frankf. 1985;95:27–30.Google Scholar
- Raven R, Gallon J. The redback spider. In: Covacevich J, Davie P, Pearn J, editors. Toxic plants and animals: A guide for Australia. Brisbane: Queensland Museum; 1987. p. 307–11.Google Scholar
- Dippenaar-Schoeman AS. Annotated check list of the spiders (Araneae) of the Mountain Zebra National Park. Koedoe. 1988;31(1):151–60.Google Scholar
- Heeres A. Natural history observations of the brown widow spider Latrodectus geometricus (Araneae: Theridiidae). Naturalist. 1991;35(1):31–4.Google Scholar
- Müller G. Black and brown widow spider bites in south Africa. A series of 45 cases. S Afr Med J. 1993;83(6):399–405.PubMedGoogle Scholar
- Lotz LN. Revision of the genus Latrodectus (Araneae, Theridiidae) in Africa. Navorsinge van die Nasionale Museum, Bloemfontein. 1994;10:1–60.Google Scholar
- Ono H. Records of Latrodectus geometricus (Araneae: Theridiidae) from Japan. Acta Arachnol. 1995;44(2):167–70.Google Scholar
- Levy G. Fauna Palaestina, Arachnida III: Araneae: Theridiidae. Jerusalem, Israel: Acad Sci Human; 1998.Google Scholar
- Dippenaar-Schoeman AS, Leroy A, de Jager M, van den Berg A. A check list of the spider fauna of the Karoo National Park, South Africa (Arachnida: Araneae). Koedoe. 1999;42(1):31–42.Google Scholar
- Forster R, Forster L. Spiders of New Zealand and their worldwide kin. New Zealand: University of Otago Press; 1999.Google Scholar
- Rafiinejad J, Tirgari S, Balali M. Dispersion of poisonous species genus Latrodectus sp. in north of Khorasan and their medical importance (Araneae: Theridiidae). Scientific Res Q Shahed Univ. 2000;27:31–8.Google Scholar
- Foord S, Dippenaar-Schoeman AS, Van der Merwe M. A check list of the spider fauna of the western Soutpansberg, south Africa (Arachnida: Araneae). Koedoe. 2002;45(2):35–43.Google Scholar
- Knoflach B, van Harten A. The genus Latrodectus (Araneae: Theridiidae) from mainland Yemen, the Socotra Archipelago and adjacent countries. Fauna of Arabia. 2002;19:321–62.Google Scholar
- Cardoso JLC, Brescovit AD, Haddad Jr V. Clinical aspects of human envenoming caused by Latrodectus geometricus (Theridiidae). J Vemon Anim Toxins incl Trop Dis. 2003;9(2):418. http://www.jvat.org.br/full/i-2003/volume_9/number_2/symposium_2002/posters_051-100/p63-sbtx-2002.htm.
- Dippenaar-Schoeman AS, Leroy A. A check list of the spiders of the Kruger National Park, South Africa (Arachnida: Araneae). Koedoe. 2003;46(1):91–100.Google Scholar
- Dippenaar-Schoeman AS, van der Walt AE, de Jager M, le Roux E, van der Berg A. The spiders of the Swartberg Nature Reserve in South Africa (Arachnida: Araneae). Koedoe. 2005;48(1):77–86.Google Scholar
- Garb JE, Hayashi CY. Modular evolution of egg case silk genes across orb-weaving spider superfamilies. Proc Natl Acad Sci U S A. 2005;102(32):11379–84.PubMed CentralPubMedGoogle Scholar
- Craemer C. Spiders a problem on export grapes. Plant Prot News. 2006;67:10.Google Scholar
- Dippenaar-Schoeman AS. New records of 43 spider species from the Mountain Zebra National Park, South Africa (Arachnida: Araneae). Koedoe. 2006;49(2):23–8.Google Scholar
- Sahra G. Renew checklist of spiders (Aranei) of Iran. Pakistan J Biol Sci. 2006;9(10):1839–51.Google Scholar
- Miller J. Latrodectus geometricus. Version 08 january. 2007. http://tolweb.org/Latrodectus_geometricus/93770/2007.01.08.
- Bayram A, Danisman T, Yigit N, Kunt KB, Sancak Z. A brown widow spider new for the Turkish araneo-fauna: Latrodectus geometricus C. L. Koch, 1841 (Araneae, Theridiidae). Turk J Arachnol. 2008;1(1):98–103.Google Scholar
- Bowles LCDE, Swaby CJA. Field guide to venomous and medically important invertebrates affecting military operations: identification, biology, symptoms, treatment. Version 2.0, 31 july 2006. San Antonio: USAF Institute for Operational Health; 2008.Google Scholar
- Dippenaar SM, Dippenaar-Schoeman AS, Modiba MA, Khoza TT. A checklist of the spiders (Arachnida, Araneae) of the Polokwane Nature Reserve, Limpopo Province. South Africa Koedoe. 2008;50(1):10–7.Google Scholar
- Eberhard WG, Barrantes G, Madrigal-Brenes R. Vestiges of an orb-weaving ancestor? The “biogenetic law” and ontogenetic changes in the webs and building behavior of the black widow spider Latrodectus geometricus (Araneae Theridiidae). Ethol Ecol Evol. 2008;20(3):211–44.Google Scholar
- Goddard J, Upshaw S, Held D, Johnnson K. Severe reaction from envenomation by the brown widow spider, Latrodectus geometricus (Araneae: Theridiidae). South Med J. 2008;101(12):1269–70.PubMedGoogle Scholar
- Kiriakos D, Núñez P, Parababire Y, García M, Medina J, Sousa LD. First case of human latrodectism in Venezuela. Rev Soc Bras Med Trop. 2008;41(2):202–4.PubMedGoogle Scholar
- Kobelt M, Nentwig W. Alien spider introductions to Europe supported by global trade. Divers Distrib. 2008;14(2):273–80.Google Scholar
- Vincent LS, Vetter RS, Wrenn WJ, Kempf JK, Berrian JE. The brown widow spider Latrodectus geometricus C. L. Koch, 1841, in southern California. Pan-Pac Entomol. 2008;84(4):344–9.Google Scholar
- Almeida RAMB, Ferreira Junior RS, Chaves CR, Barraviera B. Envenomation caused by Latrodectus geometricus in São Paulo state, Brazil: a case report. J Venom Anim Toxins incl Trop Dis. 2009;15(3):562-571. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992009000300016.
- Brazil TK, Pinto-Leite CM, Almeida-Silva LM, Lira-da-Silva RM, Brescovit AD. Aranhas de importância médica do Estado da Bahia, Brasil. Gaz Méd Bahia. 2009;79 Suppl 1:32–7.Google Scholar
- Reyes-Lugo M, Sánchez T, Finol HJ, Sánchez EE, Suárez JA, Guerreiro B, et al. Neurotoxic activity and ultrastructural changes in muscles caused by the brown widow spider Latrodectus geometricus venom. Rev Inst Med Trop Sao Paulo. 2009;51(2):95–101.PubMedGoogle Scholar
- Gerlach J, Marusik Y, editors. Arachnida and Myriapoda of the Seychelles islands. United Kingdom: Siri Scientific Press; 2010.Google Scholar
- Ng PKL, Corlett R, Tan HTW, editors. Singapore biodiversity: an encyclopedia of the natural environment and sustainable development. 1st ed. Singapore: Editions Didier Millet; 2011.Google Scholar
- Offerman SR, Daubert GP, Clark RF. The treatment of black widow spider envenomation with antivenin Latrodectus mactans: a case series. Perm J. 2011;15(3):76–81.PubMed CentralPubMedGoogle Scholar
- Taucare-Ríos A. Primer registro de la viuda marrón, Latrodectus geometricus Koch, 1841 (Araneae: Theridiidae) en el Norte de Chile. Rev Chil Entomol. 2011;36:39–42.Google Scholar
- Vetter RS, Vincent LS, Itnyre AA, Clarke DE, Reinker KI, Danielsen DWR, et al. Predators and parasitoids of egg sacs of the widow spiders, Latrodectus geometricus and Latrodectus hesperus (Araneae: Theridiidae) in southern California. J Arachnol. 2012;40(2):209–14.Google Scholar
- Muller GJ, Wium CA, Marks CJ, Du Plessis CE, Veale DJ. Spider bite in southern Africa: diagnosis and management. New Haven: Continuing Med Educ (CME). 2012;30(10):382.Google Scholar
- Raven RJ, Seeman O. Latrodectus geometricus C.L. Koch, 1841 - Brown Widow Spider. Brisbane: Queensland Museum provider for OZCAM. 2013. http://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:6909553a-1336-4db1-9c7f-436b72099c1d.
- Cnanaraneae. Portal UNIBIO, Instituto de Biología, Universidad Nacional Autónoma de México. 2013. http://www.gbif.org/occurrence/126884996.
- Museum of Comparative Zoology. Latrodectus geometricus C. L. Koch, 1841. Cambridge: Harvard University; 2013.Google Scholar
- Naturhistorisches Museum der Burgergemeinde Bern, Suiça. Latrodectus geometricus C. L. Koch, 1841. 2013. http://www.wsc.nmbe.ch/species/39047/Latrodectus_geometricus.
- iNaturalist.org. iNaturalist research-grade observations. 2013. http://www.gbif.org/dataset/50c9509d-22c7-4a22-a47d-8c48425ef4a7.
- Instituto Nacional de Biodiversidad (INBio), Costa Rica. Especímenes INBio. 2013. http://www.gbif.org/dataset/4220d19f-f919-4f36-8251-41fe1a36b1da.
- Museo Argentino de Ciencias Naturales. Colección Nacional de Aracnología - Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia'. 2013. http://www.gbif.org/dataset/34e892b0-d9c7-11de-b793-b8a03c50a862.
- Nearctic Spider Database. Latrodectus geometricus C. L. Koch, 1841. 2013. http://www.biologybrowser.org/node/1194423.
- Royal Museum for Central Africa. Arachnomorphae Collection & Systematics. Latrodectus geometricus Koch C.L., 1841. 2013. http://www.africamuseum.be/collections/browsecollections/naturalsciences/biology/arachnomorphae/browse_systematics?orderby=Full%20name&b_start:int=29700.
- Senckenberg. Collection Arachnology SMF. Latrodectus geometricus C. L. Koch, 1841. 2013. http://www.gbif.org/occurrence/207865986.
- Srinivasulu C, Srinivasulu B, Javed SMM, Seetharamaraju M, Jyothi SA, Srinivasulu CA, et al. Additions to the araneofauna of Andhra Pradesh, India-part II. Records of interesting species of the comb-footed genera Latrodectus, Rhomphaea and Coleosoma (Araneae: Theridiidae). J Threat Taxa. 2013;5(10):4483–91.Google Scholar
- SysTax: SysTax - Zoological Collections. 2013. http://www.gbif.org/dataset/7d8ed137-1d30-42f1-8b78-12a4957e4690.
- Vetter RS. Spider envenomation in north America. Crit Care Nurs Clin North Am. 2013;25(2):205–23.PubMedGoogle Scholar
- Western Australian Museum. Western Australian Museum provider for OZCAM. Latrodectus geometricus C. L. Koch, 1841. 2013. http://www.gbif.org/occurrence/search?taxon_key=2157944&dataset_key=7c93d290-6c8b-11de-8226-b8a03c50a862.
- Platnick NI. The World Spider Catalog. Version 14.5. New York: American Museum of Natural History; 2014.Google Scholar
- Ori M, Shinkai E, Ikeda H. Introduction of widow spiders into Japan. Med Entomol Zool. 1996;47(2):111–9.Google Scholar
- Vetter RS. The distribution of brown recluse spiders in the southeastern quadrant of the United States in relation to loxoscelism diagnoses. South Med J. 2009;102(5):518–22.PubMedGoogle Scholar
- Kratoska PH, editor. Southeast Asian minorities in the wartime Japanese empire. United Kingdom: Routledge Curzon; 2002.Google Scholar
- Hunter P. The human impact on biological diversity. How species adapt to urban challenges sheds light on evolution and provides clues about conservation. EMBO Rep. 2007;8(4):316.PubMed CentralPubMedGoogle Scholar
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