Protectant insecticides were tested on shelled corn in small bins. Of the candidates sprays, pirimiphos-methyl and chlorpyrifos-methyl were superior to the standard dosage of malathion in protecting the corn against attack by stored-grain insects. Fenitrothion rendered protection equal to malathion. A malathion and diatomaceous-earth dust gave the best protection, but the addition of the dust reduced the test weight of the corn.