What do the grizzly bears of Yellowstone National Park and the recent moth invasion across the San Bernardino Mountains have to do with each other? The answer lies in the bears’ notorious sweet tooth.
I was watching a documentary about grizzly bears when events took a very interesting turn. “By the end of July,” the narrator said, “the bears of Yellowstone just seem to disappear as they head above the treeline.”
What attracts the bears up there? We watch scenes of grizzlies turning over large rocks as they plunge their snouts into what lies beneath. Under the rocks are hordes of army cutworm moths, the same that invade mountain homes in early summer. “The moths,” the narrator says, “arrive in the high country to feed on wildflowers. They’ve come from as far away as the wheat fields of Kansas. They spend the night feeding on nectar, retreating at sunrise to the cool crannies in the rocks. To the grizzlies, the moths are like candy, and the bears devour up to 40,000 a day.”
For homeowners who find hundreds of the mystery moths in their cabins, this explains a lot. At sunrise, the moths squeeze into crannies around doors, windows, and open beam rafters, then get trapped inside. If you want to keep them out, seal them out with weather stripping and a quality sealant. Soon enough, though, they’ll head home to Kansas.
Homeowners in Crestline, Lake Arrowhead, and Running Springs may be baffled by all this, since moth populations there have been low. Big Bear homeowners, however, have seen large populations—suggesting large populations of wildflowers. Every rose has its thorns.
The humble moths aren’t as as noble as the grizzly bear, nor as majestic as the wonders in Yellowstone, but as they fly a thousand miles across the big western sky, they’re as sublime as anything on earth.