Latrodectus geometricus

Latrodectus geometricus, commonly known as the brown widow,brown button, 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 'cousin' to the more infamous Latrodectus mactans (black widow).

Geographic distribution

The brown widow is thought by some researchers to originate in South Africa. The origin of this species 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,Australia,Afghanistan, China, Japan,Tanzania, Dominican Republic,Cyprus,Costa Rica, El Salvador, and Brazil, and there have been sightings in the United Arab Emirates, Pakistan and Thailand.

As of 2012, researches 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 because, over time, brown widows will aggressively eradicate and replace the black widows from the areas they inhabit, and since brown widows are less venomous than black widows, this may have the effect of making those areas safer.