The species Ceratitis capitata is considered the major pest of the fruitculture in the world and million of dollars are spent annually to control and eradication of this pest. Many control programs utilize great quantity of insecticides causing damages to environment and farmers. Solutions for this situation are based on the development of new compound target-specifics with less persistence in the environment. Compounds able to interfere on the insect digestive process, either inhibiting digestive enzymes or altering peritrophic membrane permeability can be considered an alternative to decrease the use of the pesticides. Vicilins, 7S storage globulins, are proteins found widely in leguminous species and have been implicated as antibiosis factors against insects. In this work, the aim was to evaluate the effect of a vicilin purified from Erythrina veluntina (EvV) seeds on development of C. capitata larvae. Vicilins were purified by fractionated with ammonium sulphate at 70-90% saturation followed of a chromatography on a chitin affinity column. EvV was eluted with 0.1M glicine, pH, 2.0, and then dialyzed against water and lyophilized and was evaluated by SDS-PAGE and showed molecular mass around 46 kDa. EvV was added in the diet of C. capitata larvae, using an artificial diet model at 0.25 to 4% (w/w). Controls were made without presence of EvV. The effects on the larval mass and mortality were evaluated. Each treatment was conducted with 4 repetitions, each replicate containing 15 larvae. The bioassay was maintained under controlled conditions at 28 °C and 75% RH. After 5 days, artificial diets were opened and larvae were counted and weighted to determine WD₅₀ and LD₅₀. EvV at 0.25% caused 100% of mortality. EvV had a WD₅₀ of 0.175% and a LD₅₀ of 0.152% for C capitata larvae. Larvae were dissected to remove the whole guts which were submitted to Von Wisselingh test to chitin detection. Presence of chitin was confirmed in the gut. The strong effects of EvV should be explained by binding of vicilins to chitin present in peritrophic membrane from fruit fly. This work is the first to show that vicilins have an insecticidal activity to dipteran insects and can be used at pest control programs.