gpr,
If you're worried that your backyard might have black widows in it; then yes it does, more than likely.
It at least has a high potential for them to be there unless treated regularly for pests.
Black widows do a number of good things, but remember that a bite from them can be serious for the health of you and your family, children even more so. As an entomologist I'm glad that your first choice is not to kill but to relocate, just be mindful of where you are placing it and hopefully it won't ever seen a human again.
And trust me, killing it will not destroy the species in CS/Bryan