actually there is no where on this world where there arent black widows i mean no, there not in houses and stuff but there is some in ur country even California has em' but if u want some good advice stay away from em' :)
Female black widows are the spiders you'd see in pictures of black widows. The males are much smaller, do not even look like black widows, and are not dangerous. The females can be deadly but you'd have to really disturb one to get bitten. They're not like bees.
Just the opposite, Blue Mud Dauber Wasps kill black widows, so don't destroy their nests unless you like to have black widows hanging around your doorways. http://www.sutter-yubamvcd.org/Wasp_information.asp
"Black Widow" is the common name of some Spiders in the genus Latrodectus. They are easily identified by the red hourglass marking on their abdomens. The black widows are highly venomous, and can be fatal to humans.