ABSTRACT
Anastrepha fraterculus and Ceratitis capitata are widely distributed fruit flies that cause significant damageto fruit crops in tropical and temperate regions. The economic importance of these flies has resulted innumerous studies of their biology, with particular emphasis on their control and management. However,various aspects of the biology of these species are still poorly understood. In this work, we used scanningelectron microscopy (SEM) to examine the external anatomy and organization of the digestive system inthese two species. Adult males and females of A. fraterculus and females of C. capitata were dissected inphysiological saline solution, and the digestive tracts were removed and prepared for microscopy. SEMshowed that the crop was covered by a strong muscular layer that consisted of circular fibers connected bylongitudinal fibers; this arrangement was probably related to the post-feeding behavior of these flies in whichthe crop contents are regurgitated and reingested. The size of the rectum varied and was probably related tothe different body sizes of the two species.