If you missed the news this late summer about the patches of oak devastation near Sheridan and other places in the Willamette Valley, here’s a hyper-local update (our property). When the damage is in full spate (i.e. the larvae are making oaks and doug firs look dead and blighted) it’s all about the caterpillars. Right now (mid November) I am seeing these moths everywhere flopping around on the ground. Their diaphanous wings seem hardly up to the task of finding a mate and laying eggs, particularly when they are rain-soaked. However, I’m sure we’ll be seeing their leaf-chewing offspring soon enough. By the way, there is a nice description of life cycles in that first link above. I highly recommend.
Perhaps these adults arrived from Dupee Valley or even as far as Red Prairie, where the oaks looked blasted last summer, carried on the wind of fall storms? They seem to be weak flyers so it’s hard to imagine them making the trip under their own steam.
It will be interesting to see whether our oaks get the same treatment next year, having escaped till now. See previous post for a good control method: our beloved brown creepers.