Excellent question.

If you truly want to prevent their eggs hatching, leave them outside when it freezes down into the teens for a day or two. Oh, you live in GA! In that case you might have to freeze small portions in your freezer. Then don't put them back into the same bag. Put them into a clean, insect free, plastic bin. I use Rubbermaid bins to keep the rats out.

In San Antonio it never freezes hard/long enough to kill weevils. Thus I try to use up everything at Thanksgiving so that there is nothing left to grow weevils in. Then I start over in February.

Before I learned to use everything up in the fall, when my fertilizer did have weevils, I just mixed it all up (a little icky) and spread the weevils too. They were full of protein so why not? They die soon and become "meat byproducts."

Given that our FDA has allowed the producers of many of our food products to increase the level of feces and eggs from vermin in our foods, such as flour, corn meal, etc. there is no reason to believe that there would be any less in what are essentially animal feed. Mixing some Diamotaceous Earth, food grade, in is a bit easier than trying, in Georgia, to freeze that although the grains you eat can be frozen to keep those insects from hatching.

Thanks so much.

So glad I thought to ask this question before it's too late. One day last summer I opened a bag of fish meal that was just half gone and the contents were moving -- I mean, the bag was thick with weevils.

About the Diamotaceous Earth, I use it at the base of my citrus trees to help keep the ants from crawling up the trunks. I think it works.

Is there any 'organic' pesticide that could be used to treat weevils and such in stored grain?

Diatomatious earth would be the only one I know of. I've never seen it work on anything, but I've never tried it in grains, either.

Not to hijack the thread, but even a mouse can chew its way into a Rubbermaid bin. I stored bird seed in one in the garage for my bird feeders and found a hole chewed in it practically overnight. I think you've just been lucky so far that no rats have found your stash. The only thing that will keep a rodent out is a galvanized metal container, with the lid on tight. That's what the kennels around here use for storing their dry kibble too.

For insect pests in stored grain, freezing is what has worked best for me, but I've never tried the DE. I'd want to check the label before putting any pesticide, organic or not, on grain I'm planning to eat. Organic doesn't necessarily mean edible or safe.

There is a food grade DE.

Your reply reminded me of college when a mouse chewed its way into my little plastic trash bucket. Good times.

bcday, some food processors already add food grade DE to the foods you eat to aid in control of these insect larva. This has been a common practice since the 1950's at least.

Bay leaves are effective but expensive for the amount needed. Safflower seed, available from bird feeding stores, buzzed in a food processor and stirred through grain bags is effective. Cheapest method is to grow a marigold crop, pull it in the fall, hang to dry, save the dried leaves and add them to the stored grain. For additional protection, work a few drops of neem oil into any of the above.