From CBS News. – Ask fire fighters, foresters and environmentalists to find the culprit for two years’ worth of California wildfires and their fingers would unerringly point at a creature smaller than a grain of rice — the bark beetle. The tiny insect has migrated from Central America up through the U.S. and now into Canada. But not before boring into and killing millions of trees, creating the fuel for the Golden State’s raging forest fires. A Columbia University study calls the bark beetle “one of the world’s most aggressive tree-killing insects,” while the U.S. Department of Agriculture asks, “How can something so small kill something so big?” (more)