This is not a drill. California is poised to lose the Western monarch butterfly and its mysterious annual migration from the continent’s Western regions to the coastal areas between Baja and Mendocino. The list for blame is long — habitat destruction, insecticides, herbicides and, yes, good intentions, because if you’ve ever planted a showy orange milkweed in Southern California with the goal of helping the monarch, consider yourself part of the problem. So why should we care? First off, cat...