Fruit-bearing food products are controlled by phytosanitary regulatory mechanisms. Among the existing pests of economic interest, Cetatitis capitata (medfly) can be highlighted, which can infest from 250 to 400 vegetable varieties. Vicilins, constitutive proteins of chitin-binding seeds, are potentially candidates to fight this pest. Vicillin-rich fractions of Erythrina veluntina (mulungu), Canavalia ensiformis (pork beans) and Phaseolus vulgaris (common beans), isolated by affinity chromatography on a chitin column, were tested on adults of C. capitata, in laboratory and semi-laboratory bioassays. field. All were able to bind chitin, have acidic characteristics and association with carbohydrates. E. velutina vicilin was the only one to present a high lethality (100 %) in a 15 % diet (w/w). In semi-field it was observed that 10 and 15 % (w/w) of vicilin added to the diet were lethal. For TL50, death of half the population in days were 3.5 (10 %) and 3 (15 %). These results showed that vicilins are potential bioinsecticides in the control of C. capitata.