Amylase variants of Drosophila melanogaster were screened for spatial variation in adult and larva midgut α-amylase (EC 3-2-1-1, 1,4-α-glucan glucanohydrolase; Amy). Enzyme activity was detected by DNSA method during several generations in each food component for dietary control. Every strain revealed a different activity in each restricted medium, indicating that each strain has different adaptation ability to carbon source. In this study, standard medium contained starch-like cornmeal gives less dietary stress to fly than two other carbon sources. The relationship of Amy genotype and midgut amylase-activity pattern(Map) analysis was shown expression of MapP indicated highly enzyme activity at posterior region than that at anterior. In clectrophoretic analysis, it revealed Amy¹ and Amy¹·³ was MapA^(123) P^0, Amy^(4·6) was MapA^(123) P^(12). This suggests that somehow Amy genes, or their products, are differentially recognized by products of the Map gene in addition to being differentially recognized in different parts of the midgut