A case history of an asthmatic patient who developed delayed responses to intradermal and inhalation provocation tests with whole body allergen of a common beetle (cantharidine) is presented. The response was maximal at 48 hr after the test and it took almost a week for complete resolution. Prior administration of sodium cromoglycate failed to inhibit this response, whereas corticosteroid treatment completely inhibited it. An asthmatic response which appears 48 h after inhalation challenge with an insect allergen is a new variety and the mechanism needs study.