There is now enough support for the hypothesis that nominal Anastrepha fraterculus is a complex of cryptic species that are currently recognized, using morphometric procedures, as eight morphotypes that probably correspond to different biological species. In addition to this variability, there is also evidence that this nominal species presents important variation in its range of preferential host use. The aim of this chapter is to provide a comprehensive understanding of the natural host plants used by the nominal A. fraterculus under natural field conditions. This was accomplished through a bibliographic examination of information from the original sources of host plants recorded for this fly species. A total of 200 references from all regions of the Americas were examined. Data useful to the analysis were captured in a database incorporating information pertaining to host identity, original source of data, and location of distribution, where available. The list of host plants for the A. fraterculus complex comprised 177 species belonging to 40 plant families, which together accounted for 1,622 documented reports. The most highly represented families were Myrtaceae (27.1%), Rosaceae (11.9%), and Rutaceae (8.5%). The Myrtaceae exhibited a high percentage (>90%) of native species in contrast to the higher proportions of exotic species presented in the other families. Guava was the only common host shared by different populations throughout the tropical and subtropical landscapes of the Americas. The highest number of hosts was recorded in Brazil (121), followed by Argentina (40), Ecuador (40), Colombia (38), Venezuela (24), and Mexico (19). The landscapes occupied by different populations of this nominal species presented some preferential patterns in terms 90of resource use. This reinforces the hypothesis of distinct taxonomic entities because most of the plants are present throughout the range but are not found to be common hosts to all of the fly populations. In this context, the potential application of the sterile insect technique (SIT) in certain geographical areas requires knowledge of the particular hosts consumed by the target species.