I brought in some contaminated flour years ago and didn't notice or get after them soon enough. It was one of those specialty or "natural" brands so I'm not so fond of them now - thinking perhaps the mainline brands may do a better job of eliminating those type of critters at the mill? They got into an oriental (wool) rug and ate a couple of holes in it too.
I've heard anecdotal stories of that about my grandmother baking in the 1940s. Of course, when you live in rural Saskatchewan transportation is difficult and you have a bajillion children, you buy a lot of staples and do a lot of baking.
Weevils are still bad in bags of feed. It seems like every time I buy scratch grain for the chickens to have a snack weevils will turn up. You have to use it fast. The processed feeds never have the problem. I guess they use heat during the processing which kills the eggs.