The spider in your image looks most like an immature western black widow, (although it could be a related spider in the combfooted spider family). See this webpage for confirmation and to distinguish between this native spider and the exotic invasive brown widow spider:

How to identify Brown Widow Spiders

http://cisr.ucr.edu/identifying_brown_widow_spiders.html

Pesticide applications are not usually warranted, since prime web sites will usually get re-colonized within weeks or months given the local abundance of the species. Removal with a vacuum (shop vac filled with soapy water) is a good mechanical control tactic. Oftentimes, monthly vacuuming of a shop or garage situation can really reduce widow incidence. The best approach in my opinion is awareness. Learn how to identify the spiders and their webs, teach your family, and then be aware when working or playing in areas where widows are likely to be (usually within one meter of the ground, sometimes a little higher, cracks, crevices or corners protected from rain and sun during the day). Widows are nocturnal and will be hiding in these cracks / crevices during the day and will emerge at night to sit in the web and feed on insects caught in the web. These spiders can sometimes be considered beneficial since they consume cockroaches and other large nuisance insects. For more information, please visit the following webpage:

Black Widow and Other Widow Spiders

Best regards,