Widow spiders (Latrodectus), which occur in most parts of the world except for central and northern Eurasia, are venomous. The bite is painful but rarely fatal. In the Americas, the bite of the brown recluse (Loxosceles) spiders causes dead tissue in the region of the bite. The bite of Atrax, a venomous funnel weaver found in southern and eastern Australia, may be fatal. Large tarantulas of the United States are not venomous but may brush off their irritating setae.