A UCR Entomologist (Mark Hoddle) recently told the Foothill CRFG that the CDFA has recently stopped spraying in residential areas (OC, LA)...because of its observed effectiveness and because of resistance from people. He also said that UCR has finished its Southern California campaign of releasing "CA adapted" Tamarixia. UCR is now considering releasing Tamarixia in the Central Valley as a preventative measure. I vaguely recall that tamarixia's flying/spreading range was under 20 miles.
In summary, for the southern CA folks, there is almost nothing we can do now. UCR does not sell Tamarixia to the public (nor anyone). Hoddle said he believed the focus will shift to genetically developing HLB resistant citrus.