2015 November 16 

   Jean Oliver sends a photograph of a Large Yellow Underwing caterpillar found in an acorn in a local park.  Although they eat almost anything, acorns, and indeed oaks are not their usual foodplant, and I expect the caterpillars just found the old acorn shell to be a comfortable place to curl up and have a snooze.

Large Yellow Underwing Noctua pronuba (Lep.: Noctuidae)  Jean Oliver