Many of the farmers that store their corn in silos use a fumigant in with the corn. Most of the farmers around here use one called "Weevilcide". It comes in tablet form which they put into the silo as it is filled. The tablet vaporizes away to form a poison gas...phosphine. You have to have a license to use it. If the corn you have has been treated with the gas, it will keep longer at home since it will be insect free when you get it.
Interesting side point about the Weevilcide...last year one of the farm laborers nearby took a few tablets and placed them under his mobile home to get rid of pests. The whole family passed out and nearly died...if it had not been for a relative coming to get one of them. Nasty stuff.
I usually keep 1500 pounds or so of corn at home in my workshop. I use a pump duster and spray it over with sevin dust. That helps a lot. Under the pallets I have mouse/rat bait. I also occasionally dust my entire workshop and garage with sevin dust. Then use my gas blower the next day to blow everything out. It gets all the palmetto bugs, roaches, etc.
"If your sport does not put grease, blood, or dirt under your fingernails, then it's just a game!"