Phosphine in the form of proprietary tables of aluminum phosphide each containing 1000 mg phosphine was applied to bagged cocoa beans in an airtight warehouse. 7,160 tablets were applied to the top of two stacks of cocoa containing in all 2,500 tons. The store volume was 9,226 cubic meters. The mean ct product obtained was 12.48 mgh/1. Good control of all insect pests was obtained but reinfestation by the day-flying Carpophilus dimidiatus took place after airing.