I agree with the others- something is getting to your feed other than your chooks. Have you tried hanging feeders? That may help. Even if your birds DO have a heavy worm load, there's absolutely no way they should be eating that much food - in fact, I don't see how they physically COULD eat that much food.
Also, you "may" want to try switching to layer pellets. Crumbles are much more easily wasted than pellets. But do try hanging the feeders, in case something off the ground is eating the feed. Mice, rates, squirrels, even other (wild) birds can & will eat from the feeders. Also mink, opossum....etc.
As far as where the eggs are - most hens will not lay when they are getting less than 12 hours of sunlight per day, so as the days shorten, the eggs will diminish. The only thing I look forward to in December is the shortest day of the year...this year, it's 12/22 - we'll see the days slowly begin to lengthen after that, and the eggs will begin to increase come the end of January (at least in my situation). BEST of luck!
Oh, another thought - do you know anyone who has a game camera that you can borrow? That would definitley let you know what is getting to your feed!