yup seen/heard that before as well
almost 14 years ago when first purchasing our property, My land and all other land for several miles had been victim of and in the path of the Pine Beetles, look like a bad storm or twister had came through and snapped off the trees leaving stumps as high as 10 ft, the odd thing was all the Oaks were nice and healthy and were left alone, I guess not such thing as Oak beetles
I was told from someone that the Beetles will return every so many years, ( can't remember exactly ) I think was 7 years, and sure enough about 6-7 years ago we heard the sound of popping/crunching coming from the wooded area of our property and tracked it down to coming from inside the pine trees, The trees that were left from last time they hit and the smaller ones that had grown to mature pine trees, anyway! we had the Pulp wooder's come out and remove every Pine and Pop from the woods, I sure didn't want to be left with this fallen tree issue as had before as it took me forever to cleanup with my small kubota and only a 4 ft box scrape
although not sure which was worst the Pine beetle damage... or cleaning up after the pulp wood'rs,
seems though if my mind is not mistaken it was mid spring time of the year when they hit... not Fall,