<P> The brown widow has a cosmopolitan distribution . It is thought by some researchers to originate in South Africa, although this is uncertain, as specimens were discovered in both Africa and South America . They are usually found around buildings in tropical areas . They can compete with populations of the black widow spider . It is found in many areas of South Africa, the United States (including Hawaii), Australia, Afghanistan, Southern Europe, China, Japan, Dominican Republic, Cyprus, Costa Rica, El Salvador, Uruguay, and Brazil, and there have been sightings in the United Arab Emirates, Pakistan, India (Ahmedabad) and Thailand . </P> <P> As of 2012, researchers at the University of California, Riverside, suggested that the brown widow spider, newly established in Southern California, may in fact be displacing black widow spiders from the region, competing and / or fighting for territory . While certainly not definitive, this evidence does suggest that the brown widow is likely to be more hostile and aggressive towards its relative, the black widow, than the black widow is towards it . If that proves to be true, humans may be positively affected since, while brown widows are not less venomous than black widows, they inject less venom than a black widow would, thus posing less of a threat and making the area safer as they aggressively eradicate and replace the black widows over time . </P> <P> Like all Latrodectus species, L. geometricus has a neurotoxic venom . The venom acts on nerve endings causing the very unpleasant symptoms of latrodectism . However, brown widow bites are usually not very dangerous; usually much less dangerous than those of L. mactans, the black widow . The effects of the toxin are usually confined to the bite area and surrounding tissue, unlike the black widow's . Mere toxicity of the venom is not the only factor in dangerousness . Brown widow bites are minor compared to black widow bites because they cannot deliver the same amount of venom as the black widow . The LD of L. geometricus venom has been measured in mice as 0.43 mg / kg, and separately again as 0.43 mg / kg (with a 95% confidence interval of 0.31--0.53). </P>

Where did the brown widow spider come from