Concise characterization of allergy is presented and allergy to insects is discussed. Three kinds of allergy to locusts and grasshoppers are reviewed: 1) occupational allergy, i.e, allergy of personnel working with rearing and breeding these insects; 2) allergic reactions to acridid aggregations in the field; and 3) food allergy. Occupational allergy is the major subject, detailing the results of several relevant studies. Some inconsistent issues regarding reports on field allergy are illuminated and anaphylactic reaction to consumption of locusts/grasshoppers is discussed. Prevention and treatments of allergy to locusts and grasshoppers are described. Approximate molecular masses of locust allergens, as found in three studies, are summarized. A major allergen is the peritrophic membrane (today often termed peritrophic matrix or peritrophic envelope) which is secreted by the gut and excreted as a wrapping around the feces. It is concluded that the molecular structure of locust and grasshopper allergens should be revealed for full characterization.