As much as I wish those red forest splotches were caused by Mothra– how cool would that be?- the correct answer was forest die-off by means of Dendroctonus ponderosae, the mountain pine beetle.
In the grand scheme of insect plagues, Dendroctonus ponderosae should rank as one of the most damaging. It is a native beetle historically prone to outbreaks, but climate change and logging practices appear to have pushed infestations to unprecedented levels. Beetles bore into phloem, exposing the tree to a deadly fungus, and shortly thereafter the trees starve. Millions of forested acres in western North America succumb every year.
Points are awarded as follows: 10 to Biobob for getting both the beetle and the dieback. 2 consolation points to Alissa, for missing by only a few seconds, 2 to Rob Higgins for a thoughtful monograph on the topic, and a point each for ihateaphids and Michael Suttkus for the tongue-in-cheek responses of Rosy Apple Aphids and Mothra. We do award Humor points here at Myrmecos blog.