African cowpeas—known to many as black-eyed peas—are a wonder crop, loaded with agricultural, ecological, and nutritional benefit. But they have an unfortunately robust enemy which vanquishes them after a month or two in storage: the mighty bruchid, or cowpea weevil. Bruchids render that lovely bagful of food, and all that farmer’s hard work, worthless.

Suppose you dreamed up a $2, low-tech, pesticide-free bruchids solution which could be deployed repeatedly, amortizing that small investment over many years, saving the farmers’ product. It would be a trifecta of increasing food security, improving nutrition, and raising farmer incomes.

Reader, it exists. Perhaps the Purdue Improved Crop Storage (PICS) bag isn’t the catchiest of brand names, but this deceptively simple triple bag, where adopted, has been increasing farmers’ incomes significantly. The triple bags consist of two heavy plastic inner bags, one fitting inside the other, which fits inside a third woven, tear-resistant outer bag. Each bag is tied, hermetically sealing its contents, before being placed in the next bag. Storing the harvest in airtight bags eliminates the oxygen that support the critters. The eggs don’t mature and gradually disintegrate, leaving the cowpeas undisturbed.