Anaheim boasted a thriving wine industry in the late 1800s, before an unnamed affliction killed 40,000 acres of the grapevines and put 50 wineries out of business. The problem was later found to have been Pierce’s disease of grapevines. Would Anaheim be wine country today if it weren’t for Pierce’s disease? Probably not, but the sad fate of this Southern California wine industry underscores the importance of controlling the disease and the insects that spread it in California’s thriving grape growing regions.

The bacterium that causes Pierce’s disease has always existed in California, affecting a wide variety of plants, from oleanders to almonds. But the problem shot to prominence in the 1990s with...