Many insects, notably beetles and moths, subsist on stored or manufactured products of vegetable or animal origin. Most have been widely distributed through commerce.
Insects consume and destroy large quantities of foodstuffs. In so doing, they pollute them with substantial amounts of their excreta, which further damages the product and poses the risk of infection during handling or consumption. At least 30 million tons of bread grains and rice in storage are lost to insects each year. The granary and rice weevils, lesser grain borer and angoumois grain moth prefer whole grains; the saw-toothed grain beetle, flour beetles, mealworms, Mediterranean flour moth and Indian meal moth prefer flour or coarse ground cereals. The cacao moth and almond moth attack nuts and dried fruit, the bruchid beetle attacks beans, and the khapra beetle eats peanuts and grains. The drugstore beetle and the cigarette beetle infect tobacco, drugs and spices; the larder beetle and cheese skipper are important pests of dairy products, such as bacon and cheese. Goods made of animal hair, skins, wool, or feathers are attacked by clothes moth larvae and carpet beetles.